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PSY1 Stem Psychrometer Manual

1. File name 1215 0q8 v My Network Files of type Figure 51 Loading a cqs calibration file from Hard Disk Drive PSY1 Stem Psychrometer Manual Ver 4 4 Page 86 of 162 16 6 4 Calibration Live View Mode It is recommended that a minimum 30 to preferably 60 minutes thermal equilibration time be left between the handling and loading of each calibration solution These figures are arbitrary in nature and designed to err on the side of caution to ensure all thermal gradients introduced to the psychrometer through handling of the chamber introduction of samples of different temperatures be allowed to dissipate so as not to cause errors in the calibration This can cause a calibration to be a long and time consuming process An alternative protocol is to utilise the Live View feature incorporated within the calibration function This is a more intensive protocol based on active interpretation of empirical data to determine how long the psychrometer takes to return to thermal equilibrium after loading a calibration solution To activate the Calibration Live View click the Live View icon in the upper right hand corner of the calibration tab Raw Data Measurement Protocols Calibration SD Card PC Logging Stop Calibration Mew Calibration a Head Calibration Cal SH Comment ICT Demo Calibration Hall Wet Chamber Corrected Molality Bulb Temp Wet Bulb Average Figure 52 Calibration Live View icon Th
2. Mike Dixon University of Guelph Alec Downey ICT International Version 4 4 1 Contents 2 System Requirements eeesecves evt v eva eee Eae EEREREQEES EQ FEN ERN TEER VEN YER SEEN CRURA YE EYES AEER EUR Co FUP ALES AUR X Ee TREES 10 2 1 CPU PTO CESSON 10 2 2 enr 4 10 2 3 eiui ET 10 S MEE eeu ipeo cielo mmm 11 DZ OE ae GUE Rm 12 4 1 Charge the PSY Internal Battery ics ccaiceaiethsccosesccarnccties abee sesainesia E E 12 4 2 Clean the Psychrometer ChambDOef siepe ere pe EPI qe Sexo SUE eE iiS 12 4 3 Install the PSY1 Software amp USB Driver eeeeseeeseseseeeee enne nennen nnne nne nnns 12 44 TUM TNE Instrumienb OTi eb n vui qetobEMES AS udi UE OE ERUN FEE OPEP INDE E 12 4 5 COMMECE CO the IS EFUIMENIE m TM 12 4 6 Setthe Measurement Protocole A E 13 4 7 SEE EE E I E E E E E E EEE E E O A E EE E IUE 13 4 8 Install EE EE E E A E T A E A E A O E N E NE 13 4 9 Setthe Logge Wi aN seresa E ME EM EM E E UU 13 410 ME PTo o EB CT 13 AIE PUPA SED ze RR 13 MEME MOSSE ONO ihe berate Rem 14 5 1 SCS Psvehrameter cha seen a snes orti teres Svan og even cece Seen eens ones 14 5 2 COUPE E E oat ncasamnausene sn E A E 15 5 3 APE EE T T 15 5 4 Measurement leido RET T 15 5 5 Measurement of Stem Water Potential ccccccsssssssccccccssseessseeccccessaeaesseeecesessauaaseseeeees 15 5
3. cccccccsssccccessecceeesececceeceeeeesecessuaecessueceeeeees 33 7 4 Connecting Power via External 12V Battery cccccccsssccccesseccceesececeeecceeeeeceseueceeseeneeeeas 34 7 5 Connecting Power via External 12V Battery and Solar Panel cccccccssseccceseceeeeeeeeeeees 35 7 6 Sharing an External 12V Battery and Solar Panel via Daisy Chaining 36 7 7 Connecting Power via AC Mains 12V DC Plug Pack eeeeseeeeeeeernnnennne 37 o Handlnsthelnstrumellt aus cteciccid is eod re iet seva Eie vua do ae riae soe iri deem rr etes dies 38 9 AdjustiBe T hermocotlblesss iot ice roii stat ca ends iater ub aed oes dea uet odes ea e n ep cour CE 38 10 Cleaning the PSVChrOmietel sou ees tite tel A pH TE ake 40 PSY1 Stem Psychrometer Manual Ver 4 4 Page 3 of 162 TOE VSS AASV UCN Cs cassia o pute east oc notos tse de tapes d aveo un Uc o ode put aces out e e EUIS reu ec E UE 41 10 1 1 Cleaning the psychrometer using CHIOFOTOFM ccccccesecccceesececeesececeeseceeeeeeceeseeeeeeeas 42 10 1 2 Cleaning the psychrometer using Electronic Contact Cleaner sees 43 10 2 Diagnosing a Dirty THErMOcOuple cccccccsssecccessececcenecceceesececseececsenecceseeseceseugeceeseaeeetas 45 103 Storing the Stem PSVCBIOImIe t eEs rrenaren vi ee N E a e aoe 49 11 Software amp USB Driver Installation ie pre nene vera terea enna eee 51 11 1 lt Ans
4. c ccesccccsseccccesecceeesececeesececeeeceeeeeeceeseeeeeeeas 93 Zaye Jdentiyine the xvlellidasenctusiddaridie oe Ie D eiit en Iesu aoa see DI 96 17 3 3 Sample Preparation on Herbaceous Stems eene enne nnns 99 17 4 Positioning ThermocolplesS secto a Rd M a n ib et Nw M tod ibus eui E 100 17 5 dnstr mernt Attachimeltb scio v exe Ede ap Rees oae RARO E vui dvo Ree on mio ER APRI ara Eo Bass 101 176 ealhgthe EX OO SCC Sites seu E tintulu dedu piat mto mata ope uet co LIE UNE CIO od 102 17 7 IBUN usen ober e a sb ieco e Dol dd fete x es PauU Oo bMs 103 17 8 De snst llatior amp Re Install tiOTlu ee ee tene ctun anre Rua PR RN eR ERN new euntes E NVY uS OE 104 17 9 Installation on Large Diameter Stems ierant pet DERE NEC TRRE QU HEY Ex E VEP UFU UNETR DUNS FOLE EUR TRUE 105 17 9 1 Modified Surface Attachment eia E 105 17922 SRorstherBiFInstallatlOn sisde i vats beh v qa ee veld dub ever N EE 107 18 Instrument Setup amp Configuration esses eene enne nnns rne nnne 112 15 1 Jdnstr ment Information cessit rr ree FERRENT E En x ka ari N UEM Ex siete TUQUE Me RA henson deb bbs vie 112 lol ob NIME eincnssne iuo Ed de de o um RU sels d uS II 112 19 1 2 COMMENCE deuiost oue den ioe toii d ut Nope Date te de itat dubii doni UR odi 112 IM MEE S ENNO ER HM E PEU M P 113 1814 TNE X PH 113 18 1 5 Update Instrument Information citans eann ski a tn ia nii 113 153 5 SOC N E E E A E E E 113 181 7 SD Card InitialiSat
5. Note 61 allow at least 60 seconds between each of the manual readings as persistent pulsing of the Peltier cooling will add microscopic water to the thermocouple and make the measured water potential less negative closer to zero MPa Ideally 10 minute temporal sampling resolution should be employed but for test purposes 60 seconds is fine as we are just conducting a performance test not an accuracy test 16 Again download the data file serial number csv this 1s done automatically by clicking on the Download Data icon and verify the data was saved 17 This completes the functional testing of the PSY PSY1 Stem Psychrometer Manual Ver 4 4 Page 150 of 162 22 2 Electronic Contact Cleaners Manufacturer Produt MSDS TDS Picture QD Electronic Cleaner CRC XTR Precision Electronic Cleaner CO Contact Cleaner m NF Contact Cleaner 22 3 Compressed Air Manufacturer Product MSDS TDS Picture v Dick Smith Electronics BILER APEN PSY1 Stem Psychrometer Manual Ver 4 4 Page 151 of 162 22 4 Preparation of Calibration Solutions Calibration over a range of water potentials is accomplished using sodium chloride NaCl solutions the molecular weight of sodium chloride 58 4428 g mole The following Table represents a suitable range of molalities 1 e mass of salt per unit mass of water of salt solutions with the corresponding water potential equivalent at 25 C You can ma
6. 6 Connect 7 Change measurement mode from Manual to Live Mode and update settings 8 In Live Mode you will see a continuous output of dT Chamber Temperature and Thermocouple C this is refreshed at 10Hz sampling frequency 9 If the connections are ok the results should be as follows a dT in the range 0 to 1 uV b Chamber Temp stable and indicative of the ambient conditions should be within 0 1 C of actual but no necessary to test this c Thermocouple C in the range of 0 to 0 8 uV 10 Run the Instrument in Live Mode for approx 3 minutes continuously If all values remain stable within the set range the psychrometer cable connections and instrument are operating well You can log this data at any interval of your choosing by clicking on the logging interval icon under the Measurement Mode drop down box This data will be logged automatically to the SD card named serial number lve this will serve as a test of the SD card 11 Return the unit to Manual mode and perform a measurement The Peltier cooling pulse should be set to 5 seconds and wait time of 6 seconds as a default in firmware If not change this in the Measurement protocol tab first 12 Use a 1 0 molal NaCl calibration solution on a Whatmans number filter paper punched to the correct size of the well in the calibration lid PSY1 Stem Psychrometer Manual Ver 4 4 Page 149 of 162 a An initial measurement is taken of dT and Thermocou
7. Device SN Comment ICT Demo Calibration NaCl Wet Chamber Corrected Molality Bulb Temp Wet Bulb C Average Plot Against Nothing Figure 39 click calibrate once all measurements have been recorded The data points will be automatically plotted a regression line fitted the slope intercept and R2 calculated If the calibration is of suitable accuracy an R of at least 0 999 preferably 0 9999 should be possible and the slope be within the general range of 3 8 to 4 2 uV MPa and intercept of between O to 1 uV m Calibration Slope Intercept CumentCalibrationCuve 3872 387 0858 mesa 0 99991 bo I Apply Cancel Calibration Curve O Corrected Wet Bulb Calibration Curve 2 2 3 a E 2 v g e o 9 De o o B Solution Water Potential MPa Figure 40 the calibration results are automatically processed and plotted 16 4 6 Write Calibration to Firmware Click on the Apply icon located in the top right hand corner of the plot This will automatically write the calibration slope and intercept to the firmware of the PSY1 And take you to the measurement protocol tab and stop the calibration PSY1 Stem Psychrometer Manual Ver 4 4 Page 79
8. iii Wet Bulb corrected to 25 C Remove the calibration solution and replace it with the next solution Repeat this procedure for at least 3 calibration solutions The software is locked to ensure a minimum of any 3 points are recorded satisfy a calibration 6 points are preferred NOTE 31 if you check the Average box you will be able to take multiple measurements at each cal solution and automatically average the values for use as the data point for that cal solution on the graph Allow at least 10 minutes between replicate readings Whilst this option is provided if readings show sufficient variation to warrant using an average function it is recommended that you review your calibration procedure and clean the psychrometer Raw Data Measurement Protocols Calibration SD Card Br Logging Stop Calibration New Calibration v Head Calibration Cal SH Comment ICT Demo Calibration NaCl Wet Chamber Corrected Molality Bulb Temp Wet Bulb Figure 38 tick the average box if you wish to make multiple measurements at each calibration solution and average them 16 4 5 Generate Calibration Curve When at least a minimum 3 data points have been measured click on the Calibrate button at the bottom of the screen PSY1 Stem Psychrometer Manual Ver 4 4 Page 78 of 162 Raw Data Measurement Protocols Calibration SD Card PC Logging Stop Calibration New Calibration v t a s a Head Calibration caist
9. 162 Peltier Cooling Curve Peltier Cooling Curve 20 Time since end of cooling s Figure 99 Set to default Auto rescale of Peltier Cooling Curve plot PSY1 Stem Psychrometer Manual Ver 4 4 Page 142 of 162 20 4 Peltier Cooling Curve Raw Data File The Raw Data File rdf csv is a true csv file and can be directly opened in Excel It is a log of the Peltier cooling curve data for each measurement It is sampled at 10 Hz frequency and it is synchronised with the Main Data file PSYOA201 csv It contains an 8 row header line that corresponds to the same header line information of the main data file This enables direct cross referencing between data files to check the performance or cleanliness of the thermocouple against each Corrected Water Potential value recorded Providing a means of determining if readings are valid throughout the measurement period especially as an installation reaches the end of its productive life SS a pe foo e a aa ee RU Armidale NSW Australia a as Ros RR c Table 2 Raw Data logged data file of the Peltier cooling pulse curve Used for manual plotting of the Peltier cooling curve 5 11 2010 19 14 19 0500 19 91 PSY1 Stem Psychrometer Manual Ver 4 4 Page 143 of 162 This data can be manually graphed in spreadsheet software such as Excel to generate the same graph and Peltier cooling curve as the PSY1 software can generate after each manual measurement Peltier Coolin
10. 22 11 Extension Cable SD6 5 iode xao aac Noe tois NoME es opted eT e Nu pM E PEL CL DL eec 161 22 12 SDCR e MItt a tION od stet este xo eui A Io ob tu HI eet Lut Isle feo eu 161 23 COMPACT Deballss deese atrae E DE MR NINE UNS meii oU iere 162 PSY1 Stem Psychrometer Manual Ver 4 4 Page 9 of 162 2 System Requirements 2 1 CPU Processor The ICT Instrument software does not require large processing power For example it is compatible with NetBooks Minimum Recommended Processor Capacity Intel Atom Processors with a CPU N270 1 66 GHz and 1GB RAM or higher 2 2 Software The ICT Instrument software is compatible with the following Windows Operating Systems a Windows XP b Windows Vista c Windows 7 d Windows 8 e Windows Virtual OS run from a Mac computer 2 3 Screen Resolution The ICT Instrument software is written to a fixed screen resolution of 857 x 660 dpi it does not Auto Resize and works best on current model laptops that have a screen size of 11 6 or larger and a default screen resolution of 1366 x 768 the vertical height of 768 being most important otherwise you can t see the bottom of the software This means on small netbook s and some old laptops the bottom 5 or 1096 of the screen is cut off or obscured from view This can significantly limit software functionality The only netbook ICT is aware of that does support the ICT Software in full window display is the ACER Aspire One netbook It has
11. 3 15 Min Optional temporal resolution logging interval often chosen for environmental research 19 1 4 20 Min Optional temporal resolution logging interval 19 1 5 30 Min This is a Good temporal resolution as it affords the plant sufficient time to re equilibrate thoroughly yet still frequent enough to see rapid changes in plant water potential 19 1 6 60 Min Optional temporal resolution logging interval PSY1 Stem Psychrometer Manual Ver 4 4 Page 124 of 162 19 2 Live Mode Live mode is used as a diagnostic tool to ensure integrity of chamber thermocouples through stability of Thermocouple C and dT values Live mode in conjunction with Chamber Heating Protocol or Peltier Warming Protocol can also be used to test and verify a selected protocol before field deployment See Appendix A for a PSY1 Test Procedure E ICT Stem Psychrometer File PSY Help Connect to PSY Disconnect from PSY Instrument Information Raw Data Measurement Protocols Calibration SD Card PC Logging Hame ICT Demo Stem Psychrometer dt Chainb r Tanp cule Comment Armidale NSW Australia uv 22 39 deg C uv PSY Serial Ho 0006 4 Update Instrument Information scan SD OK Seriainumber PSVOA2D E Measurement status COM Ver R1 3 0G APP Ver Bia External Supply FJ Battery 4 06 v idle Plot Peltier Cooling Curve Peltier cooling curve can be plotted for the last measurement taken by the Measurement Control Stem Psychro
12. 6 Measurement of Leaf Water Potential ccccccsssssssecccccecseeesseeeccccesseeeesseeeeeeesssaaaeeseeeess 16 5 7 Measurement of Osmotic Potential cccccccccsssssssseecccccsseeesseeeccccessaeaeseeeeceessaneaseeeseess 16 5 8 PSY d Stem Psychtometeft VICTOR vicasasecesecnrncdeetracseessacegticasevsnastenssuiestns SETS Aca estas 16 5 8 1 Waste PIODIIB edes terest testudo nti mesevine dcs eEM cda E 17 5 8 2 FOwWer Manageme BIETET m 17 5 8 3 Extern DOUUBP accade eredi ecu Ded dust CM tU Oda MUN Ed UE 17 5 8 4 TOO m P 17 5 8 5 due 1234 IET c 17 5 8 6 GERNE POCO C TION erre ERE T 18 PSY1 Stem Psychrometer Manual Ver 4 4 Page 2 of 162 5 8 7 Data Storage amp MOermoLy ior re ire t ayer N o Bead v es EeRH EUR Meg d EYE UES 18 5 8 8 COMMUNICATION marean ES 18 5 8 9 Software amp Firmware onee e AE VIR AI E A ANETTR OUR 18 5 8 10 Operating Temperature Range cccsccsssccssccseccseccseccseccseeceececseecesscesscessceseceseeeaes 18 o Iheob esse edu NIMM IM M MMC M M MM IE 19 6 1 Stem Water Potential ede een epe ne ert DIN Mae ERU Ue bn E eres Re E RE TTE RUE uan CERE EM dO UNE 19 6 1 1 T rer Press Ures nen T 19 6 1 2 OsmotiemDotentialu an a vnd ulus icu op retine dunE 19 6 1 3 Matric Potential sepatu RE RR RARE nA MP EMT P NE CH RI 19 6 1 4 GESVIU deoeteresio baeo oa Va Teva sepa br rds Fade e i a pen id n vta aeta bet nds 19 6 2 Psychrormet
13. 8 362 8 359 8 326 8 323 8 315 EY WO O N O O N ey O N N O 8 287 8 279 8 262 8 251 8 244 8 240 8 219 8 21 8 208 8 205 8 191 8 184 8 18 8 173 8 169 8 155 8 148 8 14 8 138 8 134 8 121 8 114 8 110 8 103 8 10 N W 0 Ul N Og O O N lon Ul CO N N O U1 8 086 8 079 8 076 8 069 8 06 8 051 8 041 8 034 8 031 8 010 8 007 8 000 7 997 7 977 7 973 7 966 7 963 0 7 950 7 943 7 939 7 933 7 929 0 7 916 7 909 7 906 7 899 7 896 7 883 7 876 7 873 7 866 7 863 7 850 7 840 7 833 7 830 7 810 7 807 7 800 7 797 7 774 7 768 7 765 WIWININ e O W 0O OIOJOJ JO WW W W N2 UW I O W W W W OINI Oc O o o 7 752 7 745 7 742 7 735 7 732 7 719 7 710 7 703 7 681 7 678 7 671 7 655 7 649 7 646 7 640 0 7 618 7 614 7 608 0 7 592 7 586 7 583 7 577 0 7 536 7 527 7 521 7 515 7 700 7 668 7 636 7 605 7 574 7 512 gt W I WO O O A e W N2 I Ul E PSY1 Stem Psychrometer Manual Ver 4 4 Page 154 of 162 22 8 PSY1 Installation Kit Post insulation the low tack label tape is used to combine the chamber heads Use for calibration procedure and with 1 0 Molal NaCl calibration solution for checking PSY1 operation Whatman 1 Filter Paper Discs A preformulated 1 0 Molal NaCl solution to use in Calibration calibration and or Solution checking of PSY1 operation Fill the 10 ml Offset
14. Ads 59 13 23 44 REDEVICE CHOOSER exuit ape S RSEN EO Un MN RU edu ta us OUR e s nM Ne Hub e Ne ER A UR DURER SNR 60 19 3 5 IRE DISCOV OR uito er bres cae tage ea ase eect eee 60 13 3 6 RF Device Wake Up Routine iro ou doers benc ster reete rU PE Iis 61 13 3 7 ESearchTormore DEVICES easet ves a es co baciadion onan onal trust op autera 61 13 3 8 Saving discovered devices aS a grOUp ico reo ripper er Ere en RE QE x E QU vo du n E UV DE 62 14 LED cce LU S 64 14b PowerCICUlt LED Suerrin t ote oh troia tr eset reni eed bue Laeta ub eu Parece eos E 64 14 1 1 LED Flash Sequence Definitions eeesseeeeseeenenenennn nennen nns 64 14 2 USB Commiuhicatior LED Sus nass tn e o EUR vr ean Ema tenute oe emp du eae ea 64 14 2 1 PROC ITED zuo come debole one Aer dist mmt vEte dum dM e pdb pce DM TRDUeM 64 PSY1 Stem Psychrometer Manual Ver 4 4 Page 4 of 162 14 2 2 areen LEDs ood Ee ETC NIT ERTL DU ELE ONE DM S ID EOS NM OMIT UE DE M ELE 64 14 3 DEVICE PIED Wa 8 deese sotalatusiitex utpat tede sdulc o iens teda ovn hu tedstduliten d pe dtd ca pA ND LIS 65 t44 POWOL COWL c aisi dott RA MIC Er MI EMI MM P MEME 65 15 Measurement Protocols scel rteta bo Ede Rogue uet deri eov ia Drs ede opas kept desit ven ko PR NE OH Op aU MEA 66 15cb GS DESLIO NI SELL PIE Secus aee Ec eC MeL M E Md 66 15 2 MECASUFEMENT OPTIONS uis eee n opc EERE MARAE CER TER ERE RAN NR ES EUR 67 15 2 1 3C00lIDE TME Soeur ittete bte ua esad od n ap ieu
15. Connection Type Available Devices i u Device Name SerialNumber COM Port Drop down the Connection Type box ICT Compatible RF Modem COM32 located in the bottom left hand corner of the screen and select RF Radio Frequency C Show All Ports Remember Devices Connection Type PF Find Devices vV Select Device Cancel Figure 14 Device Selection Window Connection Type RF If an MCC Multi Converter RF Modem is connected to the PC it will automatically be displayed in the list of Available Devices showing the COM port it has been automatically allocated by the Windows OS 13 3 2 RF Find Devices If the message No compatible devices found is displayed before proceeding to click the Find Devices icon please check the C Device Selection Available Devices following Toe Serial Number COM Port a The MCC is connected via a USB cable to the PC b The LED of the MCC is lit up to confirm the MCC is functioning c The Connection Type has been changed from USB to RF Show Al Ports Remember Devices d Then click the Find Devices icon e rn pe vissempeies f icone Figure 15 Device Selection Window 13 3 3 RF Select Device You can now select the device ICT Compatible RF Modem by clicking on it with the mouse to highlight the device then click on the Select Device icon Alternatively you can simply double click on the device name PSY1 Stem Psychrome
16. Date 05 11 2010 Device Time 24hr 12 18 Figure 4 Manual mode Configuration and operation Click on the Get Latest Data icon and then plot the data by clicking on the Plot icon The Peltier cooling pulse is graphed and can be reviewed to illustrate the numerical results from the Dialogue box VIDEO 14 Diagnosing Dirty Thermocouples provides explanation and examples of the effect of a dirty thermocouple on the shape of the Psychrometric plateau PSY1 Stem Psychrometer Manual Ver 4 4 Page 45 of 162 The flat line shown in Figure 5 with no evidence of Peltier cooling which would generate a positive uV response is an extreme example of a dirty thermocouple and clearly shows that water has not been able to be condensed on the thermocouple due to severe contamination probably by silicon grease or perhaps plant material Peltier Cooling Curve Peltier Cooling Curve 20 Time since end of cooling s Figure 5 Shows an extreme response of a dirty Thermocouple C that requires cleaning as no water could be condensed on the thermocouple Photo 14 the corresponding contamination of the thermocouples that results in no Wet Bulb Depression being generated as water vapour could not be condensed on Thermocouple C PSY1 Stem Psychrometer Manual Ver 4 4 Page 46 of 162 The second example Figure 6 below is less extreme showing a more subtle response yet still indicating a dirty thermocouple The thermocouple ou
17. Figure 61 Generic Communication Board Serial Number Field PSY1 Stem Psychrometer Manual Ver 4 4 Page 115 of 162 18 1 16 O Clicking on this icon toggles between the individual circuit board serial numbers and the overall serial number field o Figure 62 Overall Instrument Serial Number Toggle Icon 18 1 17 APP Ver The firmware version number loaded into the application circuit board The user should review this at regular intervals and compare it against the current version available from the ICT web site www ictinternational com download html if a new version is available the user can upgrade the firmware using ICT s Boot Strap Loader Utility software This firmware version number is also stored in the header line of the data file It is used for technical support purposes by ICT technicians APP Ver Figure 63 Application Board Firmware Number Field 18 1 18 COM Ver The firmware version number loaded into the communication circuit board The user should review this at regular intervals and compare it against the current version available from the web site www ictinternational com download html if a new version is available the user can upgrade the firmware using ICT s Boot Strap Loader Utility software This firmware version number is also stored in the header line of the data file It is used for technical support purposes by ICT technicians CON Ver p 1 3 LC3 Figure 64 Generic Communications Board Firmware Number
18. P aging Stop Calibration Hew Calibration yt t Ig Head Calibration Cal 5H Comment ICT Demo Calibration NaCl West Chamber Molality Bulb Temp Corrected s 1111 cqs Wet Bulb Average T31218 cas aJ My Recent Documents Desktop 0 2 Mal 0 4 Mal My Documents 43 My Computer 1 HMol 18 80 uv 2 gt My Network File name Save as type a b Savein 3 ICT Stem Psychrometer 121 Hogs cqs Figure 50 a click the Save Current Calibration to HDD icon to save the calibration data for later retrieval b Save As Window to select a preferred location on the computer PSY1 Stem Psychrometer Manual Ver 4 4 Page 85 of 162 16 6 3 Load saved Calibration from HDD Any calibration file cqs saved to HDD can also be loaded within the calibration interface This enables a calibration to be opened edited saved as an archived file name or transferred between PSY1 instruments should the psychrometer chamber be used on more than one instrument To load a saved cqs calibration file click on the Load Saved Calibration from HDD icon Clicking on the icon opens a MS Open Window that defaults to the directory C Program Files ICT ICT Stem PsychrometerM cqs or the directory where the last cqs calibration file was saved R E 1111 cas us 1218 cas 1 My Recent Documents B Desktop My Documents gs hu Computer
19. Print window 20 3 6 Show Point Values The microvolt value for each corresponding time is displayed on the graph for each data point wherever the cursor is held over the line Peltier Cooling Curve Peltier Cooling Curve 3 4 15 05 Time since end of cooling S Figure 97 Point values displayed when moving mouse over the line In this example at 3 4 seconds after the cooling pulse Thermocouple C output is 16 05 uV PSY1 Stem Psychrometer Manual Ver 4 4 Page 140 of 162 20 3 7 Zoom Specific aspects of the plot can be zoomed in one of two ways a Select a region of the plot click amp hold the left mouse button and drag to the chosen portion of the plot The graph will now zoom in on this particular aspect b If you have a mouse with a wheel you can zoom and un zoom automatically by rolling the wheel forwards and backwards Peltier Cooling Curve Peltier Cooling Curve 10 20 30 Time since end of cooling s Figure 98 Zoom function on the Peltier Cooling curve plot 20 3 8 Un Zoom Provides an incremental reversal of each incremental zoom performed on the graph 20 3 9 Undo all Zoom Pan Provides reversal of all Zoom Pan s performed on the graph in a single command 20 3 10 Set to Default Scale Right click on the graph and select set to default scale and all modifications to the graph scale are discarded and the graph is reset to the original scale PSY1 Stem Psychrometer Manual Ver 4 4 Page 141 of
20. Start check box to enable the delayed start function PSY1 Stem Psychrometer Manual Ver 4 4 Page 129 of 162 FS Measurement Scheduler Delayed Start Delayed start allows you to set up the time when the measurements will start based on their scheduled interval Measurements will not be performed before this time Delay Until E Lx C a Disg le Delayed Start Figure 80 Measurement Scheduler Window Enable Delayed Start Next adjust the time that you require the instrument to commence measurements This can be done by typing the precise time in hours and minutes in the respective time entry fields or utilising the scroll arrows to increase or decrease the time To use the scroll arrows click in the hour entry field and click the scroll arrows up or down Once the required hour is set click in the minute s entry field and again use the scroll arrows to adjust the minutes up or down as required Once both the hours and minutes are set click ok FS Measurement Scheduler Delayed Start Delayed start allows you to set up the time when the measurements will start based on their scheduled interval Measurements will not be performed before this time Delay Until Eun ux Disable Delayed Start Figure 81 Measurement Scheduler Window Set start time When complete the Measurement Scheduler window will close returning you to the main GUI window In the Dialogue Box a message confirming the change will
21. Stem Psychrometer i File PSY Help Connect to PSY Disconnect from PSY OD on lt Instrument Information Haw Data Measurement Protocols Calibration SD Card PC Lagging Hame ICT Stem Psychrometer dT Chanter Temp Wat Butts Comment AmiddeNSWAwwa I E w ec PSY Serial Ho 1210 x A Update Instrument Information so cam _ Dovnioad Dats _ Serial Humber PSYDA201 1 Measurement Status Measurement Stopped APP Ver coMVer RI M0G gt External Supply 330V charging Plot Peltier Cooling Curve Peltier cooling curve can be plotted for the last measurement taken by the Measurement Control Stem Psychrometer Get Latest Data je Plot A Update Measurement Mode o Statistics SS i i i Statistics shown below are calculated based on measurement results INFO Please wait preparing to download captured by the ICT PSY utility software These statistics are not stored on INFO File download cancelled the PSY sensor interface INFO Device disconnected Measurment Made Manual Min Difference Max Av ws NA WA NAT Connected to ICT PSY Batt 3 90 V Port COM4 Device Date 26 09 2010 Device Time 24hr 00 47 Figure 13 The PSY1 Graphical User Interface connected to an instrument PSY1 Stem Psychrometer Manual Ver 4 4 Page 58 of 162 13 3 MCC1 RF Modem m Device Selection 13 3 1 RF
22. Usually indicates data received If the red LED is blinking occasionally and green one isn t that means that the software is trying to communicate with the board which for some reason isn t responding You should generate a Debug File to check the integrity of the USB Comms Port 14 2 2 Green LED Usually indicates data sent PSY1 Stem Psychrometer Manual Ver 4 4 Page 64 of 162 14 3 Device Firmware When using the Device Firmware Update software otherwise known as a Boot Strap Loader or BSL to update the application board the Red LED will continuously blink regardless of what battery charging is doing The board should not be powered down while the Red LED is blinking because it will halt the BSL process and the microprocessor will not have been programmed correctly While performing BSL updating the generic comms board the LEDs should be off but could be in any state because the microprocessor is being loaded with firmware and is not controlling the LEDs 14 4 Power down When the power button is pushed either a Green LED or Red LED will blink while you are holding the power button If the Green LED blinks the board will not switch off when you let go of the power button This is most likely because it is powered externally and cannot shut down If the Red LED blinks the board is ready to be powered down Letting go of the power button will start the power down sequence which will result in both LEDs blinking and fading out u
23. a Forstner bit installation on a large diameter stem PSY1 Stem Psychrometer Manual Ver 4 4 Page 111 of 162 18 Instrument Setup amp Configuration 18 1 Instrument Information The instrument information panel is a summary of the instruments setup and status It provides a simple intuitive Graphical User Interface GUI that displays the configuration settings as stored in the instruments memory non volatile RAM Important operational information such as Serial Number Firmware versions internal battery voltage external power supply and charging status are immediately obvious You can immediately download data and or change the descriptive information such as Name Comment and Psychrometer Serial Number directly on screen Instrument Informatian Hame ICT Stem Psychrometer Comment Armidale NEW Australia PSY Serial Ho 1210 Update Instrument Information SD CARD eL oat Download Data rel AUT Serial Humber Hi 42 COM Ver R1 3 0G Battery APP Ver lt External Supply Figure 54 Instrument Information Panel The function purpose and the intended use for each of these parameters is described in detail below 18 1 1 Name This field provides the user with a site Identifier to relate the data set back to the plant being measured The name is stored in the header line of the data file 18 1 2 Comment a 28 character field for the user to store a comment with the data set The comme
24. absence of significant resistances to vapour exchange eg cuticular resistance between the sample and chamber well PSY1 Stem Psychrometer Manual Ver 4 4 Page 25 of 162 6 7 Zero Offsets On occasion you will find variable zero offsets especially when operating the psychrometers on potted plants The exact cause for this has not been determined but it has been found to be mitigated by placing the pots on wooden insulators to keep them off the moist floor ground or bench Grounding of the chamber body by any means tends to induce spurious offsets and confound psychrometer operation This phenomenon is generally obvious so easy to diagnose and take steps to correct Also direct sunlight on the psychrometer installation causes large temperature gradients even with insulation and reflective foil coverings on the instruments NOTE 6 If you discover a large variation it is usually indicative of some spurious electrical effect e g static or condensation in the chamber The safest remedy in all cases is to remove the psychrometer clean it and reinstall at a new site being careful to completely seal the old site with silicon grease 6 8 Temperature Gradient The temperature gradient which results in measurement errors is that between the measuring junction and the tissue The assumption that isothermal conditions prevail within the chamber and adjacent tissue almost never holds for in situ measurements The stem psychrometer compensates for
25. all instruments within the area have had time to respond within the discovery window RF Device Chooser Save Delete Address Serial Nur Device Name Please Wait Discovering Devices Cancel Figure 18 RF Device Chooser Window Discovering devices within range 13 3 7 RF Search for more Devices RF Device Chooser Sj see Dese Address Serial Num Device Name 01000017 S PO09A01 ICT Demo Instrument Please Wait Discovering Devices Search for more devices Figure 19 RF Device Chooser Window Search for more Devices If a known instrument has not been discovered during the initial 20 second poling routine the GUI software allows you to continue to search for more devices to do so click the OK icon when asked Search for more Devices PSY1 Stem Psychrometer Manual Ver 4 4 Page 61 of 162 If all devices have been discovered click the Cancel icon to gain access to the list of devices found RF Device Chooser S see Deets Address Serial Num Device Name 01000017 o POSA01 ICT Demo Instrument Discover Connect Cancel Figure 20 RF Device Chooser Window displaying the devices within range that have been discovered 13 3 8 Saving discovered devices as a group Once the discovery routine has finished polling all compatible devices a list of all compatible devices found will be displayed Each instrument displayed in the
26. be displayed INFO Measurement Mode Updated OK PSY1 Stem Psychrometer Manual Ver 4 4 Page 130 of 162 19 4 Dialogue Box The dialogue box is located in the bottom left hand corner of the PSY1 GUI software ER ICT Stem Psychrometer File PSY Help Connect toPSY Disconnect from PSY Instrument Information Raw Data Measurement Protocols Harne ICT Demo Stem Psychrometer Comment Armidale NSW Australia PSY Serial Ho 0006 Calibration SD Card PC Logging Chamber Temp Therm C dT w m3 esc w aaa 4 Update Instrument Information SD CARD SD OK Download Data Serial Number PSY0A201 C eee sietus APP Ver LUE COM Ver R1 3 0G External Supply EJ Battery 4 06 V idle Plot Peltier Cooling Curve Peltier cooling curve can be plotted for the last measurement taken by the Measurement Control Stem Psychrometer Get Latest Data Statistics Measurment Mode Live m Live Mode Logging Interval Disabled L amp Select Live Logging Interval Spdate Measurement Mode Statistics shown below are calculated based on measurement results INFO Device disconnected captured by the ICT PSY utility software These statistics are not stored on INFO Measurement Mode Updated OK the PSY sensor interface hd Start Measurement Max Min Difference Av w amp w amp wA NA C J M aconnected to ICT PSY B
27. be initiated by clicking on the Start Measurement icon It is typically used to perform 1 An instrument verification check prior to field deployment 2 A calibration of a stem Psychrometer chamber 3 Destructive sampling of leaf tissue for leaf water potentials 4 Destructive sampling of leaf tissue or sap for osmotic potentials 5 Soil water potential measurements of excavated soil samples ETE Stem Psychrometer File PSY Help Instrument Information ICT Demo Stem Psychrometer Armidale NSW Australia PSY Serial Ho DUE Hame Comment X X X Update Instrument Information SD CARD Sp OK FE TDAZUT Ril 4 2 COM Ver R1 3 0G External Supply FJ Battery 4 05 idle Serial Humber APP Yer Download Data o Raw Data Measurement Protocols Connect to PSY s Disconnect From PSY Calibration SD Card PC Logging dT Chamber Temp Wet Bulb Measurement Status Measurement Stopped Plot Peltier Cooling Curve Peltier cooling curve can be plotted for the last measurement taken by the Stem Psyuchrameter Ed Statistics Statistics shown below are calculated based on measurement results captured by the ICT PSY utility software These statistics are not stored an the PS sensor interface Difference Max Min Au 3 Connected ta ICT PSY Batt 4 05 V Pork COME Device Date 5 11 2010 Device Time 24hr 18 32 Fi
28. below the source of the latex and the stem psychrometer can be successfully installed PSY1 Stem Psychrometer Manual Ver 4 4 Page 90 of 162 17 2 Selecting a Sample The minimum diameter of the sample stem is limited by the aperture of the chamber well of the stem psychrometer The chamber well is oblong in shape approx 6 mm long by 3 mm wide It is recommended to select stems of greater than 10 mm diameter to ensure a good and reliable vapour tight seal on the stem Cylindrical stems of smaller dimensions about 5 to 7 mm whilst theoretically possible pose a significant sealing problem and are rarely if ever successful It is recommended to avoid such difficult installations Small stems with flattened portions are more conducive to efficient sealing There is no limit on the maximum stem diameter for instrument attachment other than that imposed by the clamp size In situations where it is not possible to easily or safely access small diameter lateral branches the psychrometer can be installed on large diameter trunks or leaves This is covered in more detail in the sections Installation on large diameter stems and installation on leaves NOTE 37 stem water potential is an absolute measure of the water status of the plant tissue at the point of measurement Whilst gradients will exist vertically in the plant stem water potential measured on a lateral branch adjacent to the stem which may be small enough to attach a psychrometer using
29. chamber well PSY1 Stem Psychrometer Manual Ver 4 4 Page 102 of 162 17 7 Insulation At this point the attached instrument and portion of stem should be insulated with styrofoam or cotton wool or a suitable facsimile The foam insulation is not intended to prevent the diurnal temperature change Instead it is intended to act as a thermal buffer zone to depress the rate of temperature change during the period of measurement to determine the Psychrometric Wet Bulb Depression Finally wrap the foam covered chamber and stem with Aluminium foil to reflect direct radiation and prevent it from heating the whole installation Alternatively an insulated temperature control jacket can be fitted around the installation and connected to a bath circulating temperature controlled fluid This is usually only possible in a laboratory situation but is particularly efficient at limiting temperature gradients and maintaining constant instrument temperature two highly desirable factors in the reliable use of the instrument Photo 33 attaching a high density foam insulation jacket around the psychrometer chamber and the plant stem to provide a thermal buffer form rapid changes in ambient temperature PSY1 Stem Psychrometer Manual Ver 4 4 Page 103 of 162 17 8 De Installation amp Re Installation During installation avoid using excessive silicon grease when sealing exposed xylem and the junction between the chamber and the stem Conservative use of
30. charged from an external power supply without providing any physical pathway for water ingress For this reason it is important not to open the enclosure because opening the enclosure will void the warranty and water proofing guarantee NOTE 2 there is no reason to open the enclosure as ICT have provided water proofed access to all necessary interfaces of the instrument such as USB communication port Micro SD card and power switch WARNING 2 Water proofing cannot be achieved if the communication port cover is left unscrewed Water entry via this port WILL cause damage and is not covered under warranty 5 8 2 Power Management The instrument has its own internal 4 2V 800 mA lithium polymer battery It features a non polarised power circuit internal voltage regulation a voltage inverter to drive a 12V heater inside the psychrometer chamber if heating the chamber to prevent condensation is necessary a regulated current generator to provide the Peltier cooling current and optical isolation and lightening protection 5 8 3 External power External power can be supplied with a DC voltage supply from either a 10 W solar panel or mains powered 12V DC plug pack see Charging Powering the Instrument for specific details and charging options 5 8 4 Tools No custom tools are required for connection of power supply or instruments External power is inserted through the non polarised power bus ports of the instrument utilising a unique b
31. factor in tree defence providing energy for the vital process of compartmentalization etc Mauget Technical Bulletin 01 10 15 Therefore it is very important to have a thorough knowledge of the vascular anatomy of the experimental plant before commencing installation of the psychrometer It is recommended to use a sacrificial or non measurement tree and fully excavate the outer layers of the tree to confidently identify the depth colour and location of sapwood a b Photo 26 insufficient site preparation has been performed in a as the site preparation has failed to expose xylem This is evidenced by the small symmetrical oblong shape that perfectly matches the stem psychrometer well The psychrometer has been attached to living tissue that has grown into the chamber well creating a perfect callus cast of the chamber well on the surface of the stem In b sufficient bark and living plant tissue has been removed to expose the non living but hydraulically conductive xylem or sap wood Note the series of colour changes from the black outer edge of the bark through to the white sapwood xylem This exercise should have been performed on a non measurement tree prior to first installing the psychrometer PSY1 Stem Psychrometer Manual Ver 4 4 Page 96 of 162 Note 39 a common mistake in the installation of stem psychrometers is the failure to expose a sufficiently large area of xylem Woody plants and trees particularly utilise approx only
32. list can be individually selected and you can connect to it either by highlighting the device and clicking on Connect or double clicking on the device name itself RF Device Chooser Treatment 4 v Save Delete Treatment B DIU m e a ee 01000017 SYP09A01 ICT Demo Instrument Discover Connect Cancel Figure 21 RF Device Chooser Window Save Groups Option PSY1 Stem Psychrometer Manual Ver 4 4 Page 62 of 162 To eliminate the need to find devices each time you run the software you can create groups of instruments Once a group of instruments are discovered allocate them a name such as Treatment A and click on the Save Icon Next time you click on ICT Compatible Modem you can chose to drop down the group of sensors you wish to download as the discovery routine has already been done and remembered by the GUI Software Each instrument displayed in the list can be individually selected and you can connect to it either by highlighting the device and clicking on Connect or double clicking on the device name itself After selecting an instrument or an individual instrument from within a saved group the following screen will appear m ICT Stem Psychrometer File PSY Help Connect to PSY LOT INTERNATIONAL PSYCHROMETER INTERFACE Product Version 2 0 1 5 Release Date 21 09 2010 Connecting to PSY S connecting to ICT PSY Batt 3 89 V Port COM4 Figure 22 Conne
33. number to see if a valid CSV file can be created e Ifok set SD Card status to SD OK e If fail set SD Card status to FILENAME ERROR If fail set SD Card status to WRONG FORMAT o If fail set SD Card status to SD ERROR PSY1 Stem Psychrometer Manual Ver 4 4 Page 161 of 162 23 Contact Details ICT International Pty Ltd solutions for soil plant amp environmental monitoring WWW ictinternational com sales ictinternational com au Phone 61 2 6772 6770 Fax 61 2 6772 7616 PO Box 503 Armidale NSW Australia 2350 PSY1 Stem Psychrometer Manual Ver 4 4 Page 162 of 162
34. of 162 ICT Stem Psychrometer Calibration Results Slope 3 87 Intercept 0 06 IF vou wish to apply these settings now press OK IF you wish to review your calibration values or enter or change a comment press Cancel Cancel Figure 41 Confirmation Window before writing PSY1 Calibration settings to firmware Once the results are confirmed they are automatically written to firmware and displayed in the Calibration Settings on the Measurement Protocols tab Confirmation that the calibration has been written Ok and the calibration history saved OK is given in the dialogue box The calibration is now active for this Psychrometer and all measurements made with the PSY1 will use this calibration 30 Slope and Intercept Updated OK 30 Please Wait 231 Calibration File written OK 31 Please Wait 32 Calibration History Saved OK Warming and heating protocols are manually controlled in manual measurement made Calibration Settings Current Calibration Serial Mo Slope PSY0AB03 uv MPa Current Calibration Comment Intercept ICT Demo Calibration uv 4 Load Defaults Figure 43 new calibration slope and intercept saved to firmware and displayed in calibration settings 16 4 7 Calibration storage location The calibration data is saved to a rdf calibration file on the MicroSD card using the same name as the number located in the PSY Serial No Field This should correspond to the
35. one of the two standard clamp sizes will be directly representative of the stem water potential of the adjacent main stem or trunk of the plant This measurement will be a true reflection of the plant interaction with the ambient environment and the stem psychrometer provides a convenient and non destructive method to continuously measure that variable A clamping device is required to attach the psychrometer to a plant stem Two sizes of clamps are available that should meet 8096 of all stem psychrometer installations a Small Clamp PSY SC for stem sizes up to 25 mm diameter and b Large Clamp PSY LC for stem sizes between 25 to 50 mm in diameter The purpose of the clamp is to securely hold the psychrometer in contact with the stem of the plant Clamps are made of Lexan a polycarbonate resin thermoplastic that has great strength and thermal properties Thus the clamp will not induce a temperature gradient to the psychrometer and artificially influence the results PSY1 Stem Psychrometer Manual Ver 4 4 Page 91 of 162 Photo 21 Large Clamp attached to a woody stem PSY1 Stem Psychrometer Manual Ver 4 4 Page 92 of 162 17 3 Sample Preparation 17 3 1 Sample Preparation on Woody Stems Woody stems are preferred but most herbaceous species also lend themselves to this technique On woody stems expose a suitable area of water conducting xylem tissue or sap wood approximately 3 cm x 1 cm to ensure that the chamber well of the ps
36. precise perfectly flat surface at the bottom of the hole The perfectly flat surface enables a vapour seal between the chamber and the xylem A Forstner bit consists of two cylindrical cutting surfaces around the perimeter of the drill A centering point is used to start the hole before the two cutting edges shear the wood fibres at the edge of the bore This provides good balance and ensures a perfectly bored hole square to the surface The radial cutting edges in the centre of the drill plane off the material at the bottom of the hole with precision this produces the perfectly flat surface required for achieving the vapour seal with the psychrometer The outside diameter of the stem psychrometer chamber is 25 mm or 1 The most common Forstner bit size is 25 mm However this is too tight making insertion of the chamber into the drilled hole difficult The bark must be manually excavated with a knife to enlarge the hole to achieve insertion but it is not possible to confidently verify a vapour seal with the xylem is achieved For this reason a less common 26 mm Forstner bit must be used to drill a hole large enough to accept the chamber A 26 mm Forstner drill bit leaves a 0 5 mm gap around the perimeter of the psychrometer chamber allowing for ease of insertion without obstruction or modification of the hole The chamber is held firmly in place by the bark of the tree simplifying the attachment and clamping requirements and the bark provides an a
37. previous thermocouple It is effectively now a different instrument PSY1 Stem Psychrometer Manual Ver 4 4 Page 89 of 162 17 Installation 17 1 In situ Measurements of Stem Water Potential The stem psychrometer can be installed on woody herbaceous and hollow Bamboo stems greater than 10 mm diameter With additional care preparation and specific clamps the stem psychrometer can also be used on fruits and leaves When attaching the psychrometer it is important not to over tighten the clamping mechanism except on woody stems so as not to crush or cause damage to softer plant tissues Typically finger pressure is sufficient to correctly tighten the clamp and ensure a vapour seal between the sample and the chamber well Over tightening can in the short term affect the measured stem water potential value introducing an error and in the long term and extreme cases cause mechanical damage to the vascular tissue WARNING 12 The Stem Psychrometer should not be used with species that exude latex or resin from within the xylem If the latex is clearly compartmentalised and contained within the phloem which can be permanently removed and prevented from entering the chamber it is possible to persist with the installation and use the stem psychrometer on these species a b Photo 19 shows latex exudates in a which is unacceptable to install the stem psychrometer onto whereas b has been prepared in more detail and xylem exposed
38. radiation shield For Installation of cables An Installation disc containing Quick Start Guide Installation videos brochures and software Interface between your computer and the PSY1 Stem Psychrometer For holding the protection cover over the PSY1 chamber to prevent damage to the TS and TC thermocouples Use to easily hold and manipulate the filter paper during calibration and checking routines Page 157 of 162 The SD Card Reader allows you to Micro SD Card transfer your data from microSD ane Shuttle the PSY1 to your See Samisk PC a quick transfer method Customer must obtain e Distilled water to go in wash bottle e Chloroform e Compressed Air moisture free PSY1 Stem Psychrometer Manual Ver 4 4 Page 158 of 162 22 9 Support Log Please fill in the information below to assist in troubleshooting Customer Name Customer Comment PSY Support Log Started 30 07 2012 3 26 21 PM PSY Ver 2 0 4 8 INS Name ICT PSYCHROMETER INS Comment 24 JUL 2012 9 19 11pF PSY Ser 1234 APP Ser 55FF3FCD GCB Ser 010008BC UNT Ser PSYTC705 APP Ver R1 5 2 GCB Ver R2 2 9 DC Device Date 30 07 2012 Device Time 24hr 15 26 AU EN True AU START True AU Date AU Avail False False AU Valid False False SDC SD OK BATT Volt 4 22 V BATT Stat idle MEAS Mode Manual MEAS Livelnterval Live Mode Logging Interval MEAS Sch 99999 MEAS Status Mea
39. simply a text txt file that records and stores the raw calibration values for every calibration solution measured for a specific calibration run of a psychrometer This file is stored on the Micro SD card or can be saved to the computer s hard drive to allow loading and editing it at a later date This can be a useful feature if a calibration cannot be finished or the user wishes to save each data point for feare of the OS crashing and the calibration data lost The first line of the cqs file is the header line or comment entered by the user Then data is stored in a simple table the left hand column is the Molal solution concentration from 0 1 0 2 0 3 0 4 0 5 and 1 0 Molal which is the standard calibration concentration range The column continues for 1 2 1 4 1 6 1 8 and 2 0 Molal concentrations for Extreme environment calibration range The subsequent 3 columns of the table refer to the direct measurements recorded during calibration process Wet Bulb Chamber Temp and Corrected Wet Bulb Values are only entered if measured by the PSY1 Because the data file can be edited there made be instances where only 1 value appears in a column most commonly this would be the far right column for corrected wet Bulb if the user has entered a nominal value for the purpose of demonstrating the calibration function or have values from a previous calibration that were manually entered into the calibration file Note 35 a minimum of 3 data points must b
40. the PSY1 potted in a thermal insulating compound on the circuit board This measurement is made using a Military grade specification thermistor in an insulated environment for ultra high accuracy 18 2 5 2 CJ D Is a measure in uV of the stability of the analogue inputs 18 2 5 3 EDBO Electronic Dry Bulb Offset This is a measure uV of the electronic noise or offset from electronic zero of the instrument prior to making a measurement of Thermocouple C The PSY1 uses this value as the zero set for the measurement and is automatically performed before each measurement either in the manual mode or when automatically logging 18 2 5 4 Correction Factor Is the relationship between vapour pressure and temperature in MPa C It is applied to the value of dT in degrees to adjust the apparent water potential measurement for the effect of any temperature gradient between the sample Thermocouple S and the measuring junction Thermocouple C It is displayed in the dialogue box with the raw data for each measurement logged to the data file PSY1 Stem Psychrometer Manual Ver 4 4 Page 121 of 162 18 3 Measurement Statistics The statistics facility is designed to provide the user with a real time comparative check of the performance of a psychrometer From a series of readings the PSY1 will automatically monitor and display the Maximum Minimum and Average Water Potentials measured It will then calculate and display the difference bet
41. the field This can be done via the GUI software in the office prior to deployment in the field Once in the field and the instruments have been installed and power is either manually turned on using the power switch see turn on the instrument or by connecting external power see connecting a power supply to the instrument which causes the instrument to automatically turn on and commence logging at the predetermined time and logging interval To operate effectively this function requires that the instrument s internal clock has been either synchronised with your computer or manually set to the correct local time of the region in which you are deploying the instruments Failure to do so will result in erroneous data that will require manual post processing to correct the date amp time stamp of the collected data Note 57 the instruments can only be set to start logging 23 59 minutes prior to starting as it works on a 24 hour clock only without a date variable Therefore a longer lead time is possible if after configuring the instrument you turn the power off To activate the Delayed Start function click on the Clock icon to the right of the Update Measurement Mode icon in the Measurement Control field Measurement Control Measurment Made Live L Live Mode Logging Interval Disabled r Start Measurement Figure 79 Delayed Start Icon The Measurement Scheduler Window will appear Begin by deselecting the Disable Delayed
42. the range of only 12 uV for a 1 0 Molal solution the absence of a clear plateau representing the psychrometric Wet Bulb Depression and a long drawn out gentle gradient and failure to return to the pre pulse zero reference A recommended performance and verification check of the pscyhrometers sensitivity and performance prior to deployment is as follows place a 1 0 Molal calibration solution in the calibration lid and perform a measurement using a five 5 second cooling time and a 6 second wait time For a clean sensitive and well performing psychrometer the Wet Bulb Depression should generate an output of approx 19 uV have a pronounced plateau between 4 5 seconds and 10 seconds with a rapid drop to zero uV at around 10 to 11 seconds returning completely to and remaining stable at zero uV If this is not the case the thermocouples of the psychrometer should be cleaned see Cleaning the Psychrometer PSY1 Stem Psychrometer Manual Ver 4 4 Page 137 of 162 NOTE 58 For a particularly dirty psychrometer this procedure of cleaning and verifying may be required to be repeated up to 3 times If a satisfactory response cannot be achieved within three attempts please contact ICT International for support 20 3 1 Plot Options The graph generated by the plot function can be formatted using standard Windows formatting commands These options are available by right clicking on the graph Copy Save Image As Page Setup Print Show Poi
43. the tie down strap will force the psychrometer to slide laterally across the prepared xylem surface This has the potential to damage the sample thermocouple Thermocouple S which is raised up to touch the stem of the plant and or repositioning the chamber on remnants of living tissue that will grow into the chamber Or at very least dislodge it from the perfectly flat surface compromising the vapour seal A very successful but elaborate clamping system developed by Dr George Koch Northern Arizona University in conjunction with his collaborators from Humboldt State University in California lead by Prof Steve Sillett involved a sprung platform with custom curved mounts to fit the shape of the stem or large diameter branch that it is strapped to The whole mechanism is then secured to the stem under tension using tie down straps and buckles This technique is advantageous in that the vertically sprung mounts provide a reference for positioning the psychrometer on the stem that limits the potential for the psychrometer to slide across the xylem surface when tightening the psychrometer in place Photo 35 custom designed clamping system for large stems installation on large lateral branch of sequoia sempervirens Coast Redwood shown PSY1 Stem Psychrometer Manual Ver 4 4 Page 106 of 162 17 9 2 Forstner Bit Installation A Forstner bit is used in preference to a conventional drill bit auger bit spade or speed bore bit because it bores a
44. 1096 of their xylem for daily transpiration The remaining 9096 provides a capacitive buffer to mitigate the diurnal impact of cavitations caused by high levels of water stress Therefore what may seem like excessive damage of the stem has little if any medium to long term damage to the plant It can be considered analogous to a pruning scar Conversely failure to remove any and all living tissue cambium phloem and osmotic fluids generated by damage to vessels during excavation WILL cause major damage to the Psychrometer Within hours of installation any living tissue that has not been removed and or washed away from the installation site will begin growing into the chamber and rip the fine thermocouples from the chamber requiring the instrument to be returned to ICT for repair Photo 27 is the result of failure to expose xylem or sap wood on a redwood branch during installation Note the distinctive shape of the psychrometer well raised above the flat preparation surface There are even the three perfectly shaped copper posts moulded in callus tissue PSY1 Stem Psychrometer Manual Ver 4 4 Page 97 of 162 Photo 28 is the result of failure to fully remove all living tissues from the xylem surface through thorough washing with distilled water and drying of the surface prior to installation It only requires exposure to a small amount of cambium tissue to generate callus growth which will occur within hours of installation Photo 29 is
45. 9 Derault CallDEatlOTisssoondetet t I ute itae bete vd ne eate en eoi lateris eee ob b betont cud eris 81 16 5 Checking Tor Calibration GI te oss ioo oe io res ono SE FRE p Ever eR NR dus 82 16 6 Manual Editing ofr the CallDratiofsu us donciscu ettet able qu co as ead shadowed ccs 83 16 6 1 EdibthealibEablOF doceo tes bcot seas laniextdeonictebs imer donk dae dama toten amo pt oder Das ahud 84 16 602 Save Current Calibration to HDD a iie e ode teas ek Cosi ue E een ee nave cet h Duas a 85 16 6 3 Load saved Calibration from HDD aote ax rer ee eoru n bete REA QC C Re vex wer E AR t pe Ene ue pa 86 16 6 4 Calibration Live View Mode cccccccsssssssssecccccsscnssssescececeeeasssseecceecsenasssseeseceseeaassees 87 16 65 Calibration Summary Tile XOT etii a ponet b ra bo teh be eb e een ue oce ule oe nen 88 16 0 5 aliDFat OE uota dms sd onnsuctarmesowteennceadesnonaedaauaceasecha a badaunaceadedns casi nta sea ba cen eade 88 16 5 7 Calibration HISEODV FIlessnace s sich bebes ues bel c PR abs oso adc te M ee ada 89 17 HVS CaN AEIOMN eter rv HlT c NT 90 PSY1 Stem Psychrometer Manual Ver 4 4 Page 5 of 162 17 1 In situ Measurements of Stem Water Potential eee 90 17 2 SelectHB d Sd DIG vea nsorelelcaibenmedtedu M ce qubd tots eumd seda esters ciafc ense GeDoS sec UD 91 17 3 Sample Prepafdtloltqin scende o oett van ee ted i redis ten ivi ride Me TC MTM UM 93 17 3 1 Sample Preparation on Woody Stems
46. CARD Sp OK Download Data TN u CRE Serial Humber i PSY ABD3 a ami F i d APP Ver R1 5 1 COM Ver RI 4 5HS clear use External Supply No external supply connected Internal Battery 388v Status idle w clear amp Measurment Mode USE Wee Measurement Control clear use F Heal Manual He wj Use re T clear Use Connected En ICT PSY Batk 3 99 V Pork COMFS Device Date 26 10 2012 Device Time 24hr 17 42 Figure 35 to begin a calibration click the Start Calibration icon on the Calibration Tab Note 29 a calibration can only be performed in Manual mode If you attempt to Start a Calibration while in Live Mode or while the instrument is logging an error message is displayed PSY1 Stem Psychrometer Manual Ver 4 4 Page 76 of 162 Error Starting Calibration Mode Figure 36 Error message displayed if calibration mode is attempted when the instrument is not in Manual Mode 16 4 2 Loading the Calibration Filter Paper Place a known calibration solution on a filter paper inside the calibration lid of the Psychrometer Place the Psychrometer into an isothermal calibration chamber ideally set and regulated to 25 C and leave for at least 30 minutes to preferably 1 hour to equilibrate before making the measurement NOTE 30 It is advised to start with a 1 0 molal solution to test the i
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48. Field 18 1 19 External Supply These fields display the status of any external power supply that may be directly connected to the instrument such as a An external 12V DC power supply either mains powered or solar powered b The external voltage supply whether from Solar Panel or battery c The Internal Battery voltage d The internal battery status either idle not charging or Charging PSY1 Stem Psychrometer Manual Ver 4 4 Page 116 of 162 External Supply Solar Power Supply 12 74 62 50m Internal Battery 4 19 Status Figure 65External Power Supply Status Fields These fields are dynamically updated showing a Green check box when external supply is present or a red box with a white X when there is no external supply present The external power supply voltage and charging current can be stored to the Micro SD card as a measured parameter with each water potential valued logged This is detailed in the section on SD Logging Options External Supply External Supply E3 Figure 66 External Power Supply Status Icons 18 1 20 Battery The instruments internal 4 3V Lithium polymer rechargeable battery voltage is displayed in real time This battery voltage can be stored to the Micro SD card as a measured parameter with each water potential valued logged This is detailed fully in the section on SD Logging Options pater Figure 67 Internal Battery Voltage Field 18 1 21 Status This field indicates the status of the instrum
49. SY1 Stem Psychrometer Manual Ver 4 4 Page 21 of 162 6 3 Psychrometric measurement protocol Initialise microprocessor Take dry bulb reference EDBO Measure AT in uV Applied 10 Second Peltier Cooling Pulse Wait 6 Seconds Measure Thermocouple C Temperature Psychrometric Wet Bulb Depression in uV Measure Chamber Temp in C Apply Temperature Correction to Psychrometric Wet Bulb Depression Apply Chamber Specific Calibration and Calculate Water Potential Apply Correction for Measured AT MPa C The microprocessor begins a water potential measurement by measuring dry bulb reference or Electronic Dry Bulb Offset EDBO and appointing it a value of zero The difference in temperature of the two chromel constantan thermocouples C and S chamber air and sample respectively is measured This represents the temperature gradient between the sample and the measuring junction and is converted to C by dividing the reading by 61 the temperature coefficient of a chromel constatan thermocouple It is then multiplied by the correction factor If for example the chamber temperature i e ambient temp is 20 C then the correction factor is 8 38 MPa C You now have a measure of the error in the apparent measured water potential as a result of the temperature gradient between the tissue and the measuring junction The water potential is then automatically measured in the psychrometr
50. Selection Window a The Instrument is turned on see section Turn the PSY1 ON b You are connected to a device A USB cable must be connected between the PC and the USB port of the instrument c You are connected to the correct device that is compatible with the Utility software you are using e g PSY software will only connect to a PSY1 Stem Psychrometer not an SFM1 Sap Flow Meter The software automatically recognizes the type of device and will not connect to instruments that operate on different principles of operation 13 2 2 USB Find Devices Now click the Find Devices icon m Device Selection VM DW E Device Name Serial Number COM Port Please Wait Remember Devices Connection Type t E Find Devices vV Select Device 2 Cancel Figure 10 Device Selection Window searching for the connected device NOTE 22 To eliminate the need to conduct the Find Devices routine each time you run the software you can tick the Remember Devices check box Next time you click on Connect to PSY the last instrument connected will already be displayed in the list and you can connect to it either by highlighting the device and clicking on Select Device or double clicking on the device name PSY1 Stem Psychrometer Manual Ver 4 4 Page 56 of 162 After polling all compatible devices the compatible device that is connected is displayed m Device Selection Available Devices Device Mame S
51. VIDEOg SP03 Installation Issues NOTE Any living tissue or cells left behind will grow into the chamber and cause terminal damage to the thermocouples of the psychrometer chamber and need to be returned to ICT International for repair Please Request an RMA before returning anything to ICT 4 9 Setthe Logging Interval The stem psychrometer has a minimum temporal logging resolution of 10 minutes This limit is imposed by the thermodynamics of the Psychrometric principle The stem psychrometer chamber must be allowed time to dissipate all thermal gradients and re equilibrate with the stem prior to commencing a new measurement See section 18 Measurement Control for details 4 10 Download Data Data can be downloaded in a number of ways The simplest is to click the green Download Data icon on the main window under Instrument Information section 17 1 If a data file exists on the MicroSD card then a Windows Explorer window automatically loads providing a choice of directories to save the data file to Alternatively the MicroSD card can be physically removed and read by a computer See section 20 Downloading Data for details 4 11 Analyse Data Data is saved in a CSV file and can be analysed using your preferred spread sheet or statistics software An upgrade for SFT Sap Flow Tool Software is being written to enable analysis of stem water potential data from the PSY1 that will facilitate direct comparison with measured sap flow data where applicab
52. Webcam ROOT USB 0000 Name Nokia Internet Stick DC Control USB ICT DevicelD USB VID_0403 amp PID_6001 A8004QQR Name USB Serial Converter FTDIBUS DevicelD Connecti Message Message PSY1 Stem Psychrometer Manual Ver 4 4 FTDIBUS VID_0403 PID_6001 A8004QQRA 0000 Name USB Serial Port COM25 ng to ICT PSY on COM25 timeout MSG_SSERIAL timeout MSG_SSERIAL Page 160 of 162 Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout Message timeout MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL MSG SSERIAL 22 11 Extension Cable Specs As the PSY1 is powered from its internal battery with a non polarised charging circuit no special power cables are required A simple 2 core Figure 8 cable or Lamp Cord of following specifications is ideal Size 2 x 24 0 20 Voltage Rating 300V AC Current Rating 7 5 Amps Dimensions 2 6 x 5 1mm Conductor Area 0 75mm2 Conductor Gauge 18AWG Temperature Rating 90 C Roll Size 30m 22 12 SD Card Re Initialisation SD Card Initialisation procedure check e Initialise SD Card e Check SD Card Communication Initialisation o If ok check whether the file system is of correct format If ok check serial
53. a freezing and physical disruption protocol to separate the symplastic fluid from the cells of the leaf are placed in the calibration lid To achieve good thermal insulation from ambient thermal gradients that cause noise and measurement error the stem psychrometer chamber must be housed inside the Osmotic Potential Insulator PSY OPI Then using the PSY1 software a manual measurement can be made or repeated measurements made at a defined logging interval 5 8 PSY1 Stem Psychrometer Meter The PSY1 is a highly accurate high precision microvolt meter that has been custom designed to specifically measure stem water potential It features an integrated stand alone data logger consisting of a 24 bit resolution preamplifier and microprocessor with integrated A to D converter that outputs and logs processed data in calibrated engineering units MPa Photo 3 PSY1 Meter PSY1 Stem Psychrometer Manual Ver 4 4 Page 16 of 162 5 8 1 Water Proofing The custom designed enclosure of the PSY1 has an IP65 rating It can be submerged under 10 m depth of water equivalent to approx 0 1 MPa or 1 atmosphere without water ingress This protection is across all electrical circuitry preventing water damage that is common among other field equipment Water proofing is achieved through a unique physically separated but electrically linked dual chamber enclosure design This ensures that the internal circuitry and battery can be electrically linked and
54. access controller ACPI PNPOBO0 4 amp 384624928 amp 0 Name System CMOS real time clock ACPNPNPO103M4 amp 38462492 amp 0 Name High precision event timer ACPNPNPO000M amp 38462492 amp 0 Name Programmable interrupt controller ACPNPNPOCO4M amp 38462492 amp 0 Name Numeric data processor ACPNPNPO100M amp 38462492 amp 0 Name System timer ACPI INTO800 4 amp 384624928 amp 0 Name Intel R 82802 Firmware Hub Device ACPI PNP0303 4 amp 384624928 amp 0 Name Standard 101 102 Key or Microsoft Natural PS 2 Keyboard DevicelD DevicelD DevicelD DevicelD ACPNPNPOF13M amp 38462492 amp 0 Name Synaptics PS 2 Port Pointing Device ACPNPNPOCO9M amp 38462492 amp 0 Name Microsoft ACPI Compliant Embedded Controller ACPNPNPOC14M0 Name Microsoft Windows Management Interface for ACPI ACPI FIXEDBUTTON 2 amp DABA3FF amp 0 Name ACPI Fixed Feature Button USB All DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD USB ROOT_HUB 4 amp FCF8232 amp 0 Name USB Root Hub USB VID_046D amp PID_CO3D 5 amp C6F674 amp 0 amp 1 Name USB Human Interface Device USB VID_0403 amp PID_6001 A8004QQR Name USB Serial Converter USB ROOT_HUB 4 amp 2EEF2415 amp 0 Name USB Root Hub USB ROOT_HUB 4 amp 1BAA685 amp 0 Name USB Root Hub USB ROOT_HUB 4 amp 4DE82C58 amp 0 Name USB Root Hub USB ROOT_HUB20 4 amp 624C0C7 amp 0 Name USB Root Hub USB VID_O0C45 amp PID_62C0O 5 amp 1ECD3563 amp 08 amp 5 Name Acer Crystal Eye
55. al Ver 4 4 Page 11 of 162 4 Quick Start Guide NOTE This manual includes hyperlinked instructional videos to complement each major section for both practical operation and software function These videos are located on the ICT YouTube site www ictinternational com videos html you will require internet access to view the videos whilst reading the manual Alternatively the videos are supplied on a DVD together with the manual when you purchased the PSY1 Stem Psychrometer Videos on DVD can be supplied by ICT upon request WARNING The Thermocouples of the Stem Psychrometer Chamber are made from very fine wire only 25 um in diameter NOTE Human hair is on average 100 um thick You will require a 20 x dissection microscope to view the thermocouples You cannot see them or manipulate their position with the naked eye Thermocouples are easily broken if handled incorrectly by unprepared operators Please READ section 8 Handling the Psychrometer and WATCH VIDEO SP13 Adjustment before removing the chamber s calibration lid 4 1 Charge the PSY1 Internal Battery The PSY1 is a self contained instrument that incorporates a lithium polymer battery Before using the instrument this battery MUST be charged To choose from a range of charging options see section 7 Charging Powering the Instrument 4 2 Clean the Psychrometer Chamber The Stem Psychrometer consists of two very small welded thermocouples using very fine wire only 25 um i
56. amaging the electronics by incorrect wiring of the positive and negative terminals from an external power supply And a purpose designed and built internal charging regulator that regulates any supplied DC voltage between 4 30V DC prevents overcharging of the internal battery to ensure a long service life NOTE 9 ICT recommends the use of 12V DC power supplies as they are readily available and minimise power loss through regulation thus maximising power efficiency This means the PSY1 does not need a solar regulator when using it with a solar panel The solar panel can be connected directly to the instrument via the two wire power bus using the unique power bus plugs at either end of the instrument Please see the schematic Connecting Power directly via a solar panel that illustrates the connection With a solar panel or other 12V DC external supply attached the PSY1 will regulate the charging current from the external source and dynamically trickle charge the internal 4 2V battery For example if there is full sunlight it will charge at a maximum rate of 200 mAmp Where partial sun light or diffuse light shade strikes the solar panel the internal battery will still charge but at a reduced rate as low as only 10 mAmp The dynamic charging circuit is designed to maximise any and all available light at any time of the day or conditions to ensure maximum possible charge of the battery is achieved Because the PSY1 regulates and trickle charges th
57. an 11 6 screen with resolution 1366 x 768 dpi This is the smallest netbook that supports the software as it offers a standard full laptop screen resolution 1366 x 768 The advantage of netbooks are the lightweight and often Solid State Drives SSD which make them ideal for field use and in fact much better suited than a standard laptop They are also very cheap The only solution for netbooks with a smaller screen size is to adjust your Display Properties Settings right click on your desktop and choose properties to 1366 x 768 or higher NOTE you will need to close the Instrument software first before doing this to ensure the window displays correctly on the screen Most netbooks or laptops will not save this setting so you will need to repeat this procedure every time you start your computer PSY1 Stem Psychrometer Manual Ver 4 4 Page 10 of 162 3 Recommended Reading a Dixon M A amp Tyree M T 1984 A new stem hygrometer corrected for temperature gradients and calibrated against the pressure bomb Plant Cell amp Environment 7 693 697 b Dixon M A amp Johnson R W 1993 Interpretation of the dynamics of plant water potential In Water Transport in Plants under Climatic Stress Edited by M Borghetti J Grace and A Raschi Proceeding of an International Workshop held in Vallombrosa Firenze Italy c Shackle K 1984 Theoretical and experimental errors for in situ measurements of plant water potential Journal of P
58. an exude Kino vein sap as a wound response DO NOT use this installation site The Kino will immediately flood the psychrometer chamber and gum up the Thermocouples and prevent measurements from being made If the psychrometer becomes fouled by Kino vein sap it can be cleaned but will require several thorough cleanings It is highly recommended to clean the chamber whilst the Kino vein sap is still moist as it is easier to remove than when dry PSY1 Stem Psychrometer Manual Ver 4 4 Page 108 of 162 R Photo 38 a Forstner bit hole that has bored through a region of Kino vein within the xylem of the stem Note the blackened venation in the bottom right quarter of the hole which is where the exudates were released from Note 41 Kino is a reddish brown gummy substance formed by Eucalyptus species in response to injury Specifically it is an aqueous solution of polyphenolic compounds formed in veins or pockets in the wood or bark Kino veins also have been referred to as gum veins Kino is commonly seen as an exudate on the bark branches and trunks of many eucalypts The formation of Kino vein occurs in response to injury from insects fungi and fire It is thought to be a defence mechanism particularly in regard to pathogen infections A type of barrier zone has been reported to form in the xylem after kino vein formation Tippett and Shigo 1981 Drought stress is reported to reduce the production of kino Ethrel has been u
59. are wire push fit connection mechanism The stem psychrometer is fitted with a water proof Bulgin connector that screws to the instrument 5 8 5 Power Fail Safe Mode In the event that power is lost due to adverse radiation levels such as extended monsoonal cloudy conditions the logger will enter a hibernation mode much like a laptop However as soon as the battery is recharged the whole system will reactivate and recommence logging at the preconfigured intervals without human intervention Data will not have been recorded for the period that the PSY1 Stem Psychrometer Manual Ver 4 4 Page 17 of 162 system was in hibernation but no data collected prior to hibernation will be lost It is permanently stored in non volatile memory on the MicroSD card 5 8 6 Lightning Protection Lightning protection is achieved through the design of optical isolation physical interrupts and barriers into the circuit boards of the instrument These prevent electrical discharge from lightning running throughout the circuit and destroying the instrument This is an important protection feature against electrical discharge but it will not prevent damage and complete destruction from a direct lightning strike on the instrument Nothing can 5 8 7 Data Storage amp Memory Data is stored to a 2GB MicroSD card standard Larger capacity up to 16GB Micro SD cards can be used if required All SD card memory formats are supported including SD SDHC and SDXC Th
60. atically as the 8 character data file name When using the instrument for the first time or inserting a new SD card upon making the first measurement the data file is automatically created using this number as the file name with csv extension Once downloaded to a PC the file name can be changed but data can only be saved to the SD card in this format This serial number is also stored in the header line of the data file It is used for technical support purposes by ICT technicians Serial Humber Per n Figure 58 Serial Number Field 18 1 13 I icon clicking on the icon toggles between the overall instrument serial number and the serial numbers of the individual circuit boards that make up the instrument n Figure 59 Individual Serial Number Toggle Icon 18 1 14 APP Serial The serial number of the Application circuit board that is custom designed and manufactured specifically to measure the Stem Psychrometer This serial number is also stored in the header line of the data file It is used for technical support purposes by ICT technicians APP Serial 2 3000008 Figure 60 Application Board Serial Number Field 18 1 15 COM Serial The serial number of the communication circuit board that operates the Micro SD card USB and wireless radio communications of the instrument This serial number is also stored in the header line of the data file It is used for technical support purposes by ICT technicians COM Serial Z 01000015
61. att 4 06 V Port COM6 Device Date 05 11 2010 Device Time 24hr 18 28 Figure 82 Dialogue Box location and Function It is a field for dynamic user feedback from the instrument in response to actions performed by the user When an action is performed by the user a response is immediately displayed either confirming the action is ok or warning that the action has failed and why ERROR Calibration file doesn t exist lu INFO Sensor Information Updated OK INFO Measurement Options Updated oF Gis IMFO Please Wait INFO Calibration File Written Ok Bath 4 Dn y Pork CC Connected to ICT PSY Figure 83 Dialogue Box Example of user feedback messages amp Copy Text function icon PSY1 Stem Psychrometer Manual Ver 4 4 Page 131 of 162 19 4 1 C Clicking on this icon copies all of the information contained within the dialogue box and can be pasted into a word processing application such as Microsoft Word or Notepad This can be a useful tool in diagnosing possible problems as exact feedback from the instrument can be emailed to ICT engineers for troubleshooting ERROR Calibration file doesn t exist INFO Sensor Information Updated OK INFO Measurement Options Updated OK INFO Please Wait INFO Calibration File Written OK 19 4 2 X Clicking on this icon clears the field of any previous information Connected to ICT PSY Batt 4 00 V Port CO Figure 84 Dialogue Box Clear ico
62. ay change without notice If these links are not functional then search Microsoft Downloads page www microsoft com downloads for current locations and links PSY1 Stem Psychrometer Manual Ver 4 4 Page 52 of 162 12 Turn the Instrument on 12 1 Turn the PSY1 ON The PSY1 has a physical power switch located inside the USB communication access port To access this switch remove the communications access port bung by unscrewing the bung NOTE 15 the bung consists of two parts a the bung which is the knurled large portion of the bung and b the smaller Gore Tex cap You must unscrew the whole bung by turning the larger knurled portion of the bung otherwise you will not gain full access to the communications port a Knurled section of Bung Undo this portion of the Bung b Gore Tex Cap Do NOT undo this portion of the Bung Photo 17 The Power switch is located below the knurled bung The power switch is located above the USB port It is a small black button NOTE 16 in most cases the user should be able to use their finger to reach inside the communications access port The point of the finger can rest gently on the USB port allowing the fingernail to rock forward and depress the switch VERY LITTLE force is required to depress the power switch If you find this technique difficult you can use a small flat blade screw driver or tweezers supplied by ICT to gently depress the switch To turn the PSY1 on press and hold the
63. b driver exe This is an executable file that requires no Windows driver Wizard to install Simply double click on the executable file and the USB driver will automatically install correctly b NOTE the USB driver can be downloaded from the ICT web site www ictinternational com download usb driver ict usb driver exe c Install the software by running the Setup file Double click on the setup file psy1 r2 0 1 7 setup msi d NOTE you can check for and download the latest version of software from the ICT web site http www ictinternational com downloads html e Follows the prompts of the Install wizard f If necessary install Windows DotNET from the installation CD when prompted Then complete the installation An icon will be installed on the Desktop of your PC to run the software NOTE Microsoft System Minimum Requirements DotNet Framework is free software supplied by Microsoft in all Operating Systems Dependent upon the age of your PC and the way in which it was configured at the time of manufacture the DotNet software may not have been installed as part of the standard operating system PSY1 Stem Psychrometer Manual Ver 4 4 Page 51 of 162 ICT International utilises the DotNet programming environment to run the ICT utility software and therefore requires that it be installed on the PC prior to installing the ICT utility software The ICT installation wizard automatically checks your PC s configuration and will prompt you if DotNe
64. bility to easily remove the chamber to verify vapour sealing with the xylem This is done by putting a series of small dots of silicon grease on the outer face of psychrometer chamber Then carefully insert the psychrometer and twist the chamber in the hole to smear the grease much as you would when using the calibration lid Video 26 You can then remove the chamber from the hole and verify that a seal has been achieved Once satisfied reapply a small amount of grease to renew the vapour seal orientate the cable of the psychrometer so that it points to the ground to avoid preferentially channelling water from stem flow down into the installation and reinsert the psychrometer Then simply fasten the psychrometer to the tree using a tie down strap and buckle pulled tight against the stem Unlike fastening the psychrometer to a modified surface attachment on a large diameter stem the psychrometer does not slide across the stem surface when tensioned as it is held firmly in position by the bark Then mount the PSY1 to the tree using the mounting bracket supplied AM gt e d e Ll Gra Y EN I a x s n POP P e c gt LS ICT Internation _ Pry Lad Photo 39 PSY1 and psychrometer chamber installed in a Forstner bit hole on a large diameter stem PSY1 Stem Psychrometer Manual Ver 4 4 Page 110 of 162 17 9 2 3 Sealing a Forstner Bit Installation Silicon grease can be used in one of two ways to en
65. branches may be very large in diameter themselves exceeding the 50 mm capacity of the large clamp PSY LC or the lowest branches of the canopy may be many metres or tens of metres above the ground and not be easily or safely accessible In these instances the psychrometer must be attached directly to the main stem or trunk It is possible to achieve a successful installation on a large diameter stem using one of two methods the first is a conventional method of exposing the xylem or sap wood with a single edged razor blade or second is to employ a specialised drill known as a Forstner bit that is used in woodworking and cabinet making Both methods require customisation of the clamping mechanism to secure the psychrometer to the stem and both have issues that must be considered to achieve a successful result 17 9 1 Modified Surface Attachment The same procedure is used for a large diameter stem as is used for a small diameter stem The xylem must be exposed by removing the bark phloem and cambium and a flat surface on the xylem or sapwood prepared with a single edged razor blade large enough to attach the psychrometer and achieve a vapour seal The difficulty of achieving this is increased on large diameter stems as they are typically vertical in orientation changing the working angle for scraping the flat surface and have much thicker bark The thickness of the bark requires that a much larger area must be excavated in order to scrape a flat surfac
66. can be easily opened in Excel or SFT software These files have the potential to be very large in the range of Mb s to 100 s Mb s depending upon the logging interval and longevity of installation 21 1 3 Live Data Live data files have the file extension lve and are used for logging internal temperature dynamics to assist in the development of chamber heating protocols The file format is actually Comma Separated Values CSV file and can be easily opened in Excel or SFT software These files are typically small in the size range of 10 s to 100 s KB s 21 2 SD Card Logging Options The measurement parameters to be logged can be set on the SD Card Logging Options Window This is accessed via the PSY Menu Simply check the box against the data required to be logged Esp Card Logeing Options Sil Ed The following options reflect SO Card logging options By default Water Potential is always logged and cannot be deselected Diagnostic measurements relevant to the E tras calculations DT Diagnostic Measurements Wet Bulb Haw measurement data Lhamber Temp Raw Data Battery Voltage Ext Supply Presence Select All Update Logging Uptions Figure 102 SD Card Logging Options PSY1 Stem Psychrometer Manual Ver 4 4 Page 145 of 162 21 3 Downloading Data Data is easily downloaded from the Instrument information panel by clicking on the Download Data icon T ICT Stem Psychrometer i File PSY Help E Instrument In
67. cting an airstream at the junction of the chamber and the stem with the PSY1 in Live mode and watch the dT and Thermocouple C values for erratic fluctuations If both readings are stable during the application of a stream of air a vapour seal has been achieved and the installation is good If the values become erratic a vapour seal has not been achieved therefore the installation is not good and you must reinstall As this step is performed before applying silicon grease it is possible to modify the existing installation site If any grease has been applied before this step the whole installation site may need to be abandoned as the silicon grease will contaminate the site and affect or even prevent readings being made It may be possible to scrape off excess grease and re clean the site for re installation of the instrument but it is not recommended NOTE Large quantities of vacuum grease are not necessary and strongly advised against The vapour seal is and must be made between the flat face of the Psychrometer chamber and the xylem Vacuum grease is intended as a buffer and for sealing any exposed xylem as a result of site preparation Silicon grease cannot be used to vapour seal the chamber Eventually any gaps that are vapour sealed by the grease will fail allowing grease to ingress to the chamber and cause the installation to fail Remove as much grease as possible before uninstalling the instrument from the stem to avoid contamination of the
68. cting wirelessly through the MCC1 Radio Frequency modem to a PSY1 It states the following 1 that the software is Establishing RF Link 2 then connecting to the PSY 3 Battery Voltage is 3 89 V prior to the software actually connecting 4 And the device is located on COM 32 You are now connected to the PSY1 Stem Psychrometer wirelessly through the MCC1 Multi Converter RF Modem You have all the same functionality and speed of a direct physical connection via a USB cable plus the freedom to move around the area beyond the physical reach of the instrument You will see the Instrument Information Section filled with the configuration data of the instrument you are connected to This data is read directly from the instruments configuration held in non volatile RAM The instrument is now ready to be used The configuration can be modified logging interval set Data downloaded or readings performed manually PSY1 Stem Psychrometer Manual Ver 4 4 Page 63 of 162 14 LED s The instrument has two sets of red amp green Light Emitting Diodes LED s These diodes are programmed to give specific flash sequences to indicate different states of operation of the instrument 14 1 Power Circuit LED s The main set of LED s are connected the power circuit of the communications board and are visually accessible via a light tube adjacent to the communications access port They indicate whether the board is awake and whether the battery i
69. d wait falls very early on the plateau to measure the Psychrometric Wet Bulb Depression but exactly the same UV value as for the 10 second cooling 20 Time since end of cooling s Figure 30 Peltier Cooling Curve produced with a 10 second cooling time the plateau extends to almost 20 seconds before returning to zero reference NOTE 1 do not attempt to repeat manual measurements sequentially without allowing equilibration time typically 10 minutes between each reading It is necessary to allow vapour pressure between the chamber and the stem to return to equilibrium after having first condensed water from the atmospheric vapour of the chamber and subsequently allowing it to be evaporated it back into vapour Failure to allow this time will result in disequilibrium between the atmosphere and the stem create a compounding affect in the measurement and seemingly the sample will continue to become wetter or less negative closer to zero which is not a true representation of the plant s water potential PSY1 Stem Psychrometer Manual Ver 4 4 Page 70 of 162 15 2 2 Wait Time The Wait time is an empirically derived interval It has been determined over years of empirical observations and comparisons against sophisticated algorithms to fit tangents to the curve of the Peltier cooling curve Whilst such sophisticated algorithms are possible these tend to introduce variability into the results that do not appear by opting for a fixed time period
70. dded layer of insulation immediately around the body of the psychrometer a b Photo 36 a shows a close up of the Forstner bit cutting surfaces that create the perfectly flat xylem surface for installation of the psychrometer and b shows the Forstner bit being used in a cordless drill to bore the hole for installation of the psychrometer PSY1 Stem Psychrometer Manual Ver 4 4 Page 107 of 162 Note 40 Forstner bits are typically used by master craftsmen to make high value furniture and cabinetry work They are not designed for boring green wood fibres They require great force to push them into the material so are normally used in drill presses or lathes rather than in portable drills Unlike most other types of drill bits they are not practical to use as hand tools Therefore it is important to practice using the drill bit before using it to install a psychrometer if you are to achieve optimum results Forstner bits have no mechanism such as the flutes of a conventional drill bit to clear wood fibres from the hole As with any drilling of plant stems it is imperative that the hole is drilled in short passes regularly removing the drill bit to clean the wood fibres to prevent friction and excessive heat buildup a b Photo 37 a shows a perfectly flat bottom hole bored into the xylem of a large diameter tree using a 26mm Forstner bit b inserting the psychrometer chamber into the bored hole WARNING 15 some species c
71. ds c Next use a Kim Wipe or other such lint free tissue and place a corner of the tissue in the outer edge of the chamber well This will wick the bulk of the water up out of the chamber well WARNING 6 Be extremely careful not to touch the thermocouples with the tissue and do not attempt to rub the tissue within the chamber The intention is merely to absorb the bulk of the free water not to completely dry the chamber well d Finally blow dry with a controlled stream of compressed air 20 to 30 psi The drying phase is important as residual water must be removed from the chamber well Stubborn drops may reside around the copper posts and sustained streams of compressed air may be required to remove all the water This cleaning process may be required to be performed several times to achieve a thorough cleaning of the stem Psychrometer depending upon the severity of the contamination Once satisfied that the stem Psychrometer is clean connect the unit to the PSY1 and perform a verification test see Appendix 1 At this point you should also visually check the position of Thermocouple S using a 20 x dissection microscope If Thermocouple S requires adjustment follow the instructions in the Setup Procedure The stem psychrometer is now clean and ready for deployment PSY1 Stem Psychrometer Manual Ver 4 4 Page 42 of 162 10 1 2 Cleaning the psychrometer using Electronic Contact Cleaner Electrical Contact Cleaners are available fr
72. e Electronic Dry Bulb Offset measured prior to each measurement remaining at 0 15 uV In less obvious cases the Psychrometric plateau will show a less crisp and clean response with a typical long slow drift back to zero reference or perhaps even fail to reach zero within the measurement window E ICT Stem Psychrometer File PSY Help gt ConnecttoPSY Disconnect from PSY Instrument Information Raw Data Measurement Protocols Calibration SD Card PC Logging Name ICT Demo Stem Psychrometer dT i a emen Comment Armidale NSW Australia BM E LL PSY Serial Ho 0006 4 Update Instrument Information Serial Number PSYDA201 D Measurement Status Measurement Stopped APP Ver R1 42 coMvyers RI HIG External Supply Battery 3 94 v charging Plot Peltier Cooling Curve Peltier cooling curve can be plotted for the last measurement taken by the Stem Psychrometer Measurment Mode Manual LA f 4 Update Measurement Mode g Statistics Statistics shown below are calculated based on measurement results Measurement started 06 11 2010 04 16 30 Measurement complete 04 17 21 Results wet Bulb Depression 0 15 wv captured by the ICT PSY utility software These statistics are not stored on the PSY sensor interface Chamber Temp 22 11 C dT 0 25 V Max Min Av Water Potential Q 34 MPa Difference Connected to ICT PSY Batt 3 94 V Port COM6 Device
73. e 52 if Thermocouple C is dirty microscopic beads of water will remain attached to the thermocouple preventing it from quickly returning to its original starting temperature In extreme cases the Peltier curve will be indiscernible and simply drift indefinitely never returning to the starting temperature It should also be mentioned that a similar response may occur in samples with very wet close to zero water potentials To be rule out a dirty thermocouple always perform a verification test of the chamber before installation see Appendix A PSY Test Procedure 18 2 4 5 Measurement Stopped No measurement is currently being performed 18 2 5 Show Diagnostics The diagnostic parameters are not typically used in the course of a routine measurement This facility is designed to be used in conjunction with an ICT technician to assist in troubleshooting possible problems with the instrument such as a broken thermocouple For this reason the diagnostics parameters are hidden from view They can be turned on and turned off by accessing the PSY menu and selecting Show Diagnostics or alternatively Hide Diagnostics dT Chamber Temp Wet Bulb Cold Junction CJ cD EDEO Correction Factor Measurement Status Measurement Stopped Figure 71 Raw Data Tab with Diagnostics Displayed PSY1 Stem Psychrometer Manual Ver 4 4 Page 120 of 162 18 2 5 1 Cold Junction Is a calibrated measure C of the differential Thermocouple reference located inside
74. e Live View window initialises the microprocessor before continuously displaying the live values from all three thermocouples inside the psychrometer Both dT and Wet Bulb will be elevated well above zero uV after loading the calibration solution What must be determined is how long it takes for both values to reach and remain stable at zero uV The user can apply discretion as to what constitutes a stable zero uV in relation to thermal equilibrium being reached The values displayed below would constitute an adequate thermal equilibrium to initiate the next calibration data point measurement Live View Chamber Temp Wet Bulb ut 24 55 deg C Live Mode Exit Live Mode Figure 53 Live View Window thermal equilibrium achieved PSY1 Stem Psychrometer Manual Ver 4 4 Page 87 of 162 16 6 5 Calibration Summary file rdf The calibration summary file is attributed the name of the psychrometer chamber that was calibrated The file consists of the calibration intercept and slope that was generated after performing the minimum 3 point calibration using known NaCl solutions It also contains the basic reference information related to the calibration such as the serial number of the PSY1 instrument that the calibration was conducted with the calibration comment and the date and time the calibration was completed 0 88 3 87 PSYOABO3 ICT Demo Calibration 26 10 2012 14 48 36 16 6 6 Calibration File The cqs calibration file is
75. e for attachment of the psychrometer So large in fact that the potential for localised evaporation of the stem around the installation is greatly increased even when using silicon grease to cover the exposed site Photo 34 large areas of bark phloem and cambium must be excavated to expose a sufficiently large flat surface to install a psychrometer on the surface of a large diameter stem PSY1 Stem Psychrometer Manual Ver 4 4 Page 105 of 162 Once the site has been prepared the psychrometer must be carefully and securely attached to the stem Orientate the cable so that it points to the ground to avoid preferentially channelling water from stem flow down into the installation And carefully place the chamber directly onto the prepared surface Now a modified clamping mechanism must be employed As each installation and stem diameter is different ICT does not supply a standard clamping system for large diameter trees to support surface mounted attachment Many novel clamping systems have been developed by our customers The simplest method is to use a tie down strap and buckle which can be purchased from a hardware store of various lengths to suit the diameter of the stem The tie down strap is then wrapped around the psychrometer and pulled tight against the stem This is much more difficult than it sounds and requires the assistance of two people The psychrometer is sitting on a flat surface without any bracing so the action of tensioning
76. e internal battery no expensive low impedance cable is required A common low cost and easily available figure 8 or lamp cord cable is all that is required and can be used over long distances to connect an external power supply and or daisy chain multiple devices together to share a single external power supply Powering and charging the instrument is very easy and there are four different options to choose from providing flexibility in experimental design to suit your specific situation The following diagrams illustrate the use of the unique power bus plugs and the four different power configuration options that can be used to provide continuous trickle charging of the internal battery for long term deployment PSY1 Stem Psychrometer Manual Ver 4 4 Page 30 of 162 7 1 PSY1 Current draw All power requirements are handled via the PSY1 instrument The current draw is approx 5mA for 30 minute temporal resolution and 4 mA for 60 minutes This accounts for the 10 mA Peltier current plus application board of the logger There is a base draw of 3 5mA continuous and the application board is only awake for a minute every 30 minutes such as cooling taking measurements so approximately 5mA during a 30 minute measurement mode and about 4mA during a 60 minute measurement mode If you communicate via USB and radio those values will change depending on the frequency and duration of communications It is possible to operate the PSY1 at hour
77. e measured or manually entered to be able to generate a calibration slope and intercept Any fewer data points cannot yield a suitably linear calibration PSY1 Stem Psychrometer Manual Ver 4 4 Page 88 of 162 16 6 7 Calibration History File The calibration history file maintains a chronological record of all the calibrations performed on the psychrometer over the life of the instrument Every time a calibration is made and saved using the four digit serial number of the psychrometer the raw data for each calibration solution are stored in the file including l wet bulb depression ii chamber temperature at which the measurement was made and the iii corrected wet bulb depression IV Serial Number of the PSY1 V Comment Vi Date amp Time It provides a good reference to look at calibration drift over time HCDATE 26 10 2012 14 47 49 CC Check Calibration Drift CS PSYOABO3 01 2 45 25 00 2 45 02 4 55 25 00 4 55 03 6 40 25 00 6 40 O4 7 90 25 00 7 90 05 9 80 25 00 9 80 10 19 00 25 00 19 00 12 14 16 18 __ 20 HCDATE 26 10 2012 14 41 30 CC ICT Demo Calibration CS PSYOABO3 01 2 60 25 00 2 60 02 4 50 25 10 4 49 03 6 20 24 90 6 22 04 7 90 24 80 7 94 05 9 60 24 80 9 65 10 18 80 24 90 18 85 12 14 16 18 20_ Note 36 if the thermocouple is broken and replaced the relevance of the chronological calibration data are lost A new thermocouple will have no correlation with the calibration history of a
78. e memory capacity of the standard 2GB MicroSD card is approximately 443 years for the primary data file when all parameters are logged at a 10 minute temporal interval the maximum frequency 5 8 8 Communication Is via a direct USB cable interface to a computer No RS232 serial to USB adapters are required Alternatively every instrument includes a 2 4 GHz transceiver for wireless two way communication This feature is standard in all PSY1 instruments manufactured after April 2012 and does not require activation or upgrading of the instrument Wireless communications up to a distance of 250 m line of sight is achieved when used with an MCC1 radio modem 5 8 9 Software amp Firmware Software and firmware updates are automatically available via the ICT web site www ictinternational com download html Every time you run the software and or the instrument within internet access the web site is automatically checked for possible updates If an update is available you are given the option to down load and install the update Firmware within the microprocessor of the instrument is automatically updated via the USB Boot Strap Loading function The process takes less than 10 minutes and ensures your system is updated with the latest functionality and features 5 8 10 Operating Temperature Range Maximum operating range is between 80 C to 40 C A minimum temperature of 40 C is possible due to the incorporation of heaters built under the micr
79. eaner Recommended electrical contact cleaners and cleaning procedures for cleaning the psychrometer using both options are documented below z Soe anal Prosci Ser Virtreaiz Fugen Al Or P L A Photo 10 Analytical Reagent Chloroform CHC15 Photo 11 CRC QD Electronic Cleaner PSY1 Stem Psychrometer Manual Ver 4 4 Page 41 of 162 10 1 1 Cleaning the psychrometer using Chloroform VIDEO 12 Watch how to clean the Psychrometer using Chloroform a Invert the psychrometer chamber and flood the chamber well with the organic solvent chloroform This is done using an eye dropper to deliver several drops of Chloroform directly onto the thermocouples Let stand for between 5 to 10 seconds longer if severely contaminated ensuring not to allow the chloroform to evaporate WARNING 5 If chloroform is allowed to evaporate while in the chamber well of the Psychrometer it will further contaminate the thermocouples Any and all of the organic compounds dissolved by the chloroform must be washed out with distilled water Failure to do so results in these dissolved contaminants being evenly distributed and coating the thermocouple further exacerbating the original contamination This contamination will be visible as a fine white film b Then using a wash bottle of distilled water immediately rinse away the dissolved contaminants by squirting a steady stream of water into the chamber well rinsing continuously for approx 3 5 secon
80. econds before stopping and all lights are extinguished The Instrument will turn off Confirmation of this is positively reinforced by the software automatically disconnecting No further current will be drawn from the internal battery The Instrument is now ready for transport or storage NOTE 18 Whilst the PSY1 is connected to external 12V power it cannot be turned off either by using the manual power switch or the software function Pressing and holding the power switch will just display a Green LED Using the software will display the warning External Power Connected and the software will not automatically disconnect PSY1 Stem Psychrometer Manual Ver 4 4 Page 54 of 162 13 Communications Connect to the Instrument Start the software by double clicking the PSY icon on the desk top of your PC ux ICT Stem Psychrometer 13 1 1 The opening Splash Screen displays the following 000 l type of instrument being operated Stem Psychrometer The connection Status Not Connected Product Version 2 0 1 7 Dee dah seme intel oka cr NR Release Date 20 11 2010 Not Connected File Menu along the top of the Window Function buttons a Connect to PSY b Disconnect from PSY pum m AR Figure 8 PSY1 Software Splash Screen NOTE 19 the Disconnect from PSY icon is greyed out as the instrument is not connected 13 1 2 A status bar along the bottom of the window A status bar along the bottom of the window a No
81. ect FAT32 pur 6 Name the Volume Label PSY1 Eject ER 7 Check the Quick Format box Cut E guck Format 8 Click Start Copy Create Shortcut Rename Properties sn J Cose Default allocation size Volume label PSY 1 Figure 57 Microsoft Windows Right Click Menu for Formatting a Drive Note 46 The PSY1 works fine with FAT and FAT32 file formats It is not designed to be compatible with exFAT extended File Allocation Table format also known as FAT64 This is a new format that has yet to be adopted by commercially available SD cards for precisely the reason that it would be incompatible with most electronic instruments mobile phones and cameras 18 1 10 Format Check If the format check is ok a check of the serial number is performed to see if a valid CSV file can be created If this check is ok the SD Card status to reported as SD OK 18 1 11 File Name Error If the instrument serial number has been lost or corrupted the check will fail and the SD Card status is reported as FILENAME ERROR At this point please contact your local ICT distributor in your country or ICT International direct for support PSY1 Stem Psychrometer Manual Ver 4 4 Page 114 of 162 Note 47 the SD card is hot Swappable meaning it can be ejected and inserted while connected The SD card status is updated in real time 18 1 12 Serial Number The Overall instrument serial number is displayed This serial number is used autom
82. ectly applicable across a wide range of variable ambient temperatures NOTE the psychrometric reading of water potential is temperature dependent If the psychrometer is used at ambient temperatures which differ from the calibration temperature by more than ten degrees then corrections using the formula should not be strictly relied upon For example it is common to calibrate the psychrometer at 25 C If one routinely uses the instrument at say 15 C and applies the correction an unknown potential error could be introduced It would be PSY1 Stem Psychrometer Manual Ver 4 4 Page 26 of 162 advisable to calibrate the instrument at or near the temperature at which it will normally be used A very useful exercise would be to calibrate the instrument at a variety of temperatures and assess the relationship between temperature and calibration coefficient for the individual instruments This will enhance the reliability of the instrument 6 9 Condensation Temperature gradients which induce condensation on the inner chamber walls should be avoided For every bar 0 1 MPa of measured water potential a temperature gradient of 0 012 C or more will induce condensation If that gradient is such that the sample tissue is cooler than the chamber body then condensation will occur on the sample and most likely be absorbed and redistributed If however the reverse gradient is the case then condensation will form on the inner chamber walls and intr
83. ensus ima ies aM Codt ted aM 135 ZO MD PIO iod Hi o RE ERU Ed RU TCU An DEN dUL MDC RUA EPI T MA db ELE NND 135 20 2 Peltier cooling GubVe PIOLusssssios iE ei ieir io ino Eo oxi Nri gente su eden Ds Dein ba Dra Roi Ero Pia abeo obvia IG DRE OR DenE 136 20 3 Peltier Cooling Curve Diagnostic Tool nenne 137 20 9 1 Plot Opto aean CPN SSC AR Fee M ES eL cO PEDI oec 138 PAO i MEE Greco aaea EN EE RO TREE EN PE oe eer een Tree NN 138 20 33 SAV CMM ae Ce c OE EE 138 20 5 4 Pape SetiD zudem eU eti Er dan E d P EM RM EE 139 20 39 PANG EE 139 20 36 SHOW PONEVA ES ocon T E ueteres TO E uses E OO 140 DOWD LOON ar E E HA 141 203o UNZOON eed a E E E 141 2039 MAG Zoom Paseset 141 20 3 10 Set tO Default CIl Enere r E ae EN HR exe d Eri UNUS 141 20 4 Peltier Cooling Curve Raw Data Files c eiontsuee o tm eei derro tie uve tached aeons 143 21 Data Storage amp DoWnloadlng aude de dove tr Docendi REY e aveie cavi iv ees ros 145 ZA TD Mamata ileen aaa tess ve ds alesee steven dy it done ivanie ts dp ueenvelisteee 145 21 12 Raw Measurement DGatqg o o oot Supe ee boesodtutiaxur s nent tended Roeectelladuns sone d Dav UP s 145 21 3 5 Hye Dal angie hel eet eee dtu uM M LR IE E haoue has 145 21 2 SDcard Login ODEUODS tee nbi Eolo tesi etd M Eois Sont rexit Erde e EOD le es iSi eue ERE ap 145 21 3 DownloadiHP Datdssnioseseineieat etaient ia E oe Mi eee ru AL Eau 146 ZU Vig USB CaDlIg aede co peto RO CA be Re E deb ca
84. ent If the instrument is fully operational and charged the field displays the message Idle Alternatively if the instrument s internal battery has dropped below the operational threshold of 3 7V and an external power is attached the instrument displays the message charging hemina Figure 68 Internal Battery Voltage Status Fields 18 2 Raw Data Tab The Raw Data tab displays in real time data being measured by the instrument Each output is clearly displayed and labelled A Measurement Status indicator keeps the user informed of the progress of each measurement when connected to the software PSY1 Stem Psychrometer Manual Ver 4 4 Page 117 of 162 Haw Data Measurement Protocols Calibration 5D Card PC Logging Chamber Temp Wet Bulb aT Measurement Status Intialising Measurement Figure 69 Raw Data Tab displays measured values from the Thermocouples of the Psychrometer No values are displayed either before a measurement is made or after a measurement is completed This is done to avoid confusion over where the values on screen have come from After a measurement has been completed the results can be reviewed in the dialogue box located in the bottom left hand corner of the GUI window Haw Data Measurement Protocols Calibration SO Card PC Logging Chamber Temp Wet Bulb Measurement Status Measurement Stopped Figure 70 No values are displayed in the Raw Data Tab Fields unless a measurement is i
85. erialNumber COM Port IET Stem Psychrometer PETAT COM4 C Show all Ports Remember Devices Connection Type i 3 y Select Device 5 Cancel Figure 11 Device Selection Window reporting the device that was found connected 13 2 3 USB Select Device You can now select the device by clicking on it with the mouse to highlight the device and then clicking on Select Device Alternatively you can simply double click on the device name After selecting the device the following screen will appear PICT Stem Psychrometer Connect to PSY LOT INTERNATIONAL PSYCHROMETER INTERFACE Product Version 2 0 1 5 Release Date 21 03 2010 Connecting to PSY S Connecting to ICT PSY Batt 3 89 V Port COM4 Figure 12 PSY1 connecting PSY1 Stem Psychrometer Manual Ver 4 4 Page 57 of 162 It states the following 1 that the software is connecting to the PSY 2 Battery Voltage is 3 89 V prior to the software actually connecting 3 And the device is located on COM 4 You are now connected to the PSY1 Stem Psychrometer You will see the Instrument Information Section filled with the configuration data of the instrument you are connected to This data is read directly from the instruments configuration held in non volatile RAM The instrument is now ready to be used The configuration can be modified logging interval set Data downloaded or readings performed manually PICT
86. ernational com ICT Stem Psychrometer ICT International Phy Ltd V Www ictintematianal com Product Name ater Psvchrarneter Product Version 2 0 5 4 Release Date 15 08 20 1 2 INTERNATIONAL Figure 86 PSY1 About Splash Screen PSY1 Stem Psychrometer Manual Ver 4 4 Page 133 of 162 19 5 7 Check for Updates The updates fucntion can be automated however a manual updates search option is availble via the Help menu This will force the software to check the ICT web site http www ictinternational com downloads html and search for any new software or firmware udates that may be available 19 5 8 Support The support option is split into two key functions 1 Create Support Log and 2 Start Debug File These functions are designed to automatically collect configuration information for use by ICT engineers in troubleshooting problems 19 5 8 1 Create Support Log The support log automatically generates a file summarising the configuration settings of the PSY1 that can either be directly emailed to ICT or sent as a text file attachment An example of a Support Log is shown in Appendix C Support Log 19 5 8 2 Start Debug File The Debug file interrogates the computer you are using documenting the Operating System CPU capacity RAM connected Hardware USB Com ports and drivers It then records the communication sequence between the computer and ICT Devices connected to any USB Com port This file is created when y
87. esinous tissue or significant proportions of living cells intermingled with xylem conduits e g ray cells great care should be taken in sample preparation to avoid contamination of the sample site The importance and significance of fully removing all living tissue and cleaning the site thoroughly are demonstrated in Video 21 Installation Issues PSY1 Stem Psychrometer Manual Ver 4 4 Page 94 of 162 Photo 24 use a wash bottle of distilled water to wash away the spilt contents of cells Photo 25 use a lint free tissue such as a Kim Wipe to dry the exposed xylem rub vigorously several times to ensure the stem is completely dry PSY1 Stem Psychrometer Manual Ver 4 4 Page 95 of 162 17 3 2 Identifying the xylem It is not always easy to determine the water conducting xylem or sap wood of a tree Many underestimate the bark thickness of trees For example there is a widespread misconception that the Lemon Gum Eucalyptus citriodora is thin barked This due to the presence of a band of green tissue resembling the deeper cambial layer of other species when the tree s outermost bark is scarified or scratched This phenomenon is common to numerous trees including the London plane Chinese elm and many tropical species This green tissue layer is actually composed of living cells which contain chlorophyll and enable the tree trunk to produce energy via photosynthesis Indeed rather than being an indication of thin bark it is an important
88. eter Manual Ver 4 4 Page 36 of 162 7 7 Connecting Power via AC Mains 12V DC Plug Pack eA CATH if E 12V DC Plug PSY1 Stem Psychrometer Manual Ver 4 4 Page 37 of 162 8 Handling the Instrument The chamber housing is very robust and should withstand even the roughest abuse However the delicate sensors are exposed when the calibration lid is removed Care should be taken to avoid touching the chromel constantan junctions mounted in the chamber well Aside from temperature gradients thermocouple contamination is the most important source of error in the psychrometric determination of water potential Diagnosing a dirty thermocouple and eliminating this hazard is discussed in detail in Cleaning the Psychrometer 9 Adjusting Thermocouples This section outlines the basic procedure for the use of the stem psychrometer and should be read before attempting to inspect or operate the instrument VIDEO 11 Adjusting Thermocouples Watch this BEFORE Opening the Chamber Photo 6 25 u Chromel Constantan thermocouples viewed under a dissection microscope at 20X magnification WARNING NEVER grab or pull the thermocouples with forceps This will break the very fine 25 u wires and result in the instrument being returned to ICT for factory repair PSY1 Stem Psychrometer Manual Ver 4 4 Page 38 of 162 The recommended procedure is to use a very fine pair of forceps to push or nudge the thermocouple wires from side to s
89. f water and slowly evaporate back into the atmosphere of the chamber The volumes of water and the times taken to change from liquid to vapour phase will be determined by the vapour pressure within the chamber which is in equilibrium with the plant It should be PSY1 Stem Psychrometer Manual Ver 4 4 Page 67 of 162 understood that as conditions become more negative it may be necessary to increase the cooling time to ensure a sufficient volume of water is condensed onto Thermocouple C to generate a Psychrometric Wet Bulb Depression If insufficient water is condensed in a dry environment very negative water potentials the cooling effect and hence the plateau will not remain for the necessary 6 seconds in order to record a measurement and instead generate a false reading or most commonly no reading at all Peltier Cooling Curve Peltier Cooling Curve 6 Second wait time but there is no plateau to measure Time since end of cooling s Figure 27 Peltier cooling curve with insufficient cooling time Conversely if the cooling time is too long in a wet environment values close to zero MPa then it may be that the time interval for absorption of the condensed water back into the atmosphere is so long that the minimum 10 minute logging interval cannot be used This situation can be identified by reviewing the Peltier cooling pulse If the temperature of Thermocouple C is failing to return to zero by the end of the 40 second sampli
90. fes ads CR ER PERAN S ae L e MR PUER IA B ON CHRVEURE ORE OS 147 214 Mia MIeroSD card USB AOSDEBE ut beet i eductus oi cient eni a ud bute ted no ra bete p Qf 147 21 5 WINDOWS TAT 32 compatible ueber eve da oio Usa eee PUR pt tops levia evt eso Enid re bae oue edd 148 21 6 MicroSD Card Memory Capacity sis ete reb uasa au e Eet iut fa ute metis Ne Dea cu eut eee 148 217 RENAMING data TES usar Gur rivale ater deter esie reet eens 148 218 Data Filed orditur duci veitl as tue alia aden IRA TE AE 148 22 ADDSHOIEBSS i isedu niii pU TRE tetti tau DIDI do A eR eR les ipt EU EE 149 22 1 PSY Test PFOCGQUEG iode dines cb dabat odia eese eoo eaae die ce dnb dei eene 149 22 2 El ctronic Contact Cle ales cuui ooo teta b sel rni eas bul beata ub e E 151 229 iOONHIDIeSSBOl Abest demos a tratto miii imb iom d usnm tet t d otis 151 224 Preparation of Calibration Solutions aser ie PEE Er acu es aaa 152 22 5 Osmotic Coefficients and Water Potentials of Sodium Chloride Solutions 153 PSY1 Stem Psychrometer Manual Ver 4 4 Page 8 of 162 22 6 Copper Constantan Thermocouple Conversion Chart cccccccccccccsccscceceeeeeeeeeeeeeeeeeeeeeeees 153 22 7 Correction Factors Ambient Temperature Relationship MPa C ee 154 22 8 SPSYT T nstallatiori KI co poete 2s have PRI DERE UR E EAQUE SU LI TP ELA TUNE PUE S EU SAU HA A EPTRT URN 155 22D SUPHO WO TET 159 22 10 Debug I ea E EMEN eM MM dede M 160
91. formation llame ICT PEYCHRONMETER comment SS PSY Serial Ho 1219 f A Update Instrument Information SD CARD eL uk Download Data Figure 103 Download Data icon Clicking this icon immediately brings up the Save As Window to select a directory to save the data to Once the data is downloaded you are prompted to rename or delete the data file Save In E ICT Stem Psychrameter pict PSY 5W R2 0 3 1 msi E PSYDA201 SD csv Lt icr PSy SW R2 0 3 2 msi E PS 04201 brochure test cs hiu Recent QS ICT PSY SW RZ D 4 D msi al PS 04201 brochure test xlsx Documents IBICT PS 3 5W R2 0 4 7 msi E PSYOA201 livesd coy iE live made chamber heat csyv f PSY OAZDU1verB z csv E live mode chamber heat xlsx PSYDAZD1 verB ces 7 new test csv 7 PSYOAGO1 csy E PS Y AZ I monday csi E PS YOASUZ csv E PSYOAZO1 Mondays E PSYDABOS csv e PSYOAZO1 SWEET csw E PSYDA amp D4 csv a PSYOAZU csv A Am E PS O4606 cs I PSWDA201 DOZ cev quPSYTlS2 0005 R1 4 6 20062011 fub E PSYOAZOI DU3 csv LagPST7192 DOS R1 4 7 D4072011 fub 3 E PSYOAZD1 vecs ge PS 7192_0005_R1 4 8_14072011 Fub E PSYOA2O1 rdf csv ggPsvT192 D D5 Ri 4 23 D8nez011 Fub Desktop My Documents Mu Computer My Network Save as type All files Cancel Figure 104 Microsoft Windows Save As window PSY1 Stem Psychrometer Manual Ver 4 4 Page 146 of 162 21 3 1 V
92. four digit Serial Number of the psychrometer that has been calibrated NOTE 32 You should enter the 4 digit serial number of the Psychrometer chamber into this field at the commencement of the calibration and click the update sensor information button 16 4 8 Loading a Different Calibration A new or different calibration can be activated by entering a different chamber serial number in the PSY Serial No field and clicking the update sensor information button If the calibration file exists on PSY1 Stem Psychrometer Manual Ver 4 4 Page 80 of 162 the MicroSD card it is loaded as the active calibration and all measurements made with the PSY1 will have the raw Wet Bulb Depression data converted to Water Potential MPa using this calibration Instrument Information Hame ICT FSYCHROMETER PSY Serial Ho 1220 x A Update Instrument Information E eae Figure 44 PSY Serial No field is located in the instrument information panel Change this number to load a different calibration file 16 4 9 Default Calibration The default calibration is a historical average slope and intercept of a small sub sample fo all psychrometers ever made It is a good general calibration that will always place the measured water potential within the right range but it cannot be directly relevant to the specific output of any one psychrometer If a psychrometer is being used and a calibration file does not exist the PSY1 will be warn the use
93. fully Be sure to listen for the clicking sound when inserting otherwise the PSY1 will rightly state NO CARD SDCARD NO CARD Download Data Figure 56 SD Card Status amp Download Icon Note 44 Clicking on the Download Data icon will take you directly to the SD Card Tab This tab is detailed fully in the SD Card section 18 1 7 SD Card Initialisation Upon insertion of the MicroSD card the PSY1 Initialises the card then performs a simultaneous communication and format check If the SD card fails the communication and PSY1 Stem Psychrometer Manual Ver 4 4 Page 113 of 162 initialisation check the SD card status is reported as SD ERROR This means the SD card is damaged and should be replaced with a new MicroSD card Note 45 ICT International recommends SanDisk MicroSD Card s however any brand of MicroSD card is compatible and should perform well in the PSY1 within the limits of the card s own specifications 18 1 8 SD Card Formatting If the SD card uses a higher level of formatting such as exFAT then a message will appear saying WRONG FORMAT at which point you would reformat the SD card to FAT32 format 18 1 9 Instructions to reformat a MicroSD Card Open Format FLASH DRIVE M AE 1 Remove the card from the PSY1 Explore R 2 Place it in the USB card reader aoe p AutoPlay File system 3 Insert it in to a computer Sharing and Security 4 Right click on the drive and choose Format i norton antivirus 5 Sel
94. g Curve 9 14 30 0200 9 14 31 0600 19 14 33 0000 9 14 38 0600 9 14 40 0000 19 14 42 0800 19 14 44 0200 19 14 45 0600 19 14 47 0000 19 14 48 0400 19 14 49 0800 19 14 51 0200 e t m m t p oO m 19 14 19 0000 19 14 20 0400 19 14 21 0800 19 14 23 0200 19 14 24 0600 19 14 26 0000 19 14 27 0400 19 14 28 0800 19 14 34 0400 19 14 35 0800 19 14 37 0200 1 1 1 1 Time Since end of Cooling S Figure 100 Peltier cooling curve manually graphed in Excel Peltier Cooling Curve Peltier Cooling Curve 30 25 20 15 uy 10 C1 eo 5 0 10 20 30 40 Time since end of cooling s Figure 101 Peltier cooling curve automatically graphed in PSY1 software PSY1 Stem Psychrometer Manual Ver 4 4 Page 144 of 162 21 Data Storage amp Downloading The PSY1 stores three types of data files to the internal MicroSD memory card 21 1 1 Main Data File Main data files have a csv file extension and are a true Comma Separated Values CSV data file that can be easily opened in Excel or SFT software They are used for logging water potential measurements and associated raw data These files are typically small in the size range of 10 s to 100 s KB s 21 1 2 Raw Measurement Data Raw Measurement Data files have the file extension is rdf and are used for logging the high temporal frequency 10 Hz for the Peltier Cooling Curve data The file format is actually Comma Separated Values CSV file and
95. gure 47 plotting a new calibration against an existing calibration from file If the calibration curves are significantly different 25596 then a full 6 point calibration should be performed and saved the firmware of the PSY1 to replace the old calibration The psychrometer should be cleaned every time it is uninstalled and or prior to deployment If the psychrometer has been stored for any length of time even if it has been stored correctly with a smear of vacuum grease around the inside of the calibration lid and taped up to prevent oxidisation of the thermocouples Oxidisation of the thermocouples will still occur even if only mildly but it has the potential to influence readings and be the cause of potential errors in calibration even if the chamber is perceived to be Clean Always clean the psychrometer before calibration PSY1 Stem Psychrometer Manual Ver 4 4 Page 82 of 162 m Calibration Slope Intercept R 2 Current Calibration Curve 0 98803 Cancel Historical Calibration Curve 3 703 1 504 0 94984 Calibration Curve O Corrected Wet Bulb Calibration Curve M Historical Corrected wet Bulb Historical Calibration Curve 3 AZ i0 T q A q a dum o e b Solution Water Potential MPa Figure 48 comparison of a new calibration against an existing calibration from file 16 6 Manual Editing of the Calibration For best results calibration of a psychrometer should be done within a short period
96. gure 73 Measurement Control Mode set to Manual PSY1 Stem Psychrometer Manual Ver 4 4 Page 123 of 162 Note 53 All readings initiated in the manual mode are saved to the micro SD card and saved direct to the PC if PC Logging is activated It is also possible to manually apply reverse Peltier currents to warm the thermocouple or invoke a chamber heating protocol by pressing the respective icons These protocols are described in detail in the Reverse Peltier warming and Chamber Heating sections 19 1 2 10 Min This is the minimum temporal resolution logging interval allowed in an automated data collection mode Data collected more frequently than this has a high probability of disrupting the thermodynamics of the chamber by preventing the return to thermal equilibrium between readings and increasing microscopic beads of water on the thermocouples that will artificially appear to increase the readings make the measurements less negative therefore introducing serious errors This can be empirically demonstrated in the Manual mode by making successive measurements without any time interval between each measurement Note 54 It is recommended not to use 10 min temporal resolution logging interval unless you have done a precursor study of the plant at the specific site under the prevailing environmental conditions to verify that 10 minute temporal resolution is indeed sufficient time to allow re equilibration between measurements 19 1
97. hamber Heating schedule should be set before deploying the instrument and checked periodically throughout the experiment See section 14 Measurement Protocols for details 4 7 Calibrate the Sensor The Stem Psychrometer MUST BE calibrated before each measurement The calibration employs a 6 point measurement protocol using known NaCl molality solutions Watch VIDEO 3 SP10 Calibration Procedure The calibration must be done under isothermal conditions Watch VIDEO 4 SPO9 Calibration Chamber at a controlled temperature of 25 C to generate a specific slope and intercept that characterises the specific response of the individual thermocouples A detailed calibration function is provided within the PSY1 software that can be used to generate and automatically load your new calibration into the PSY1 firmware See section 15 Calibration Procedure for details and watch VIDEO 5SP 14 Calibration The calibration is applied and tracked via the four digit serial number of the psychrometer chamber and will remain in the instrument in non volatile RAM until changed by the user This number must be manually entered into the instrument firmware See sub section 17 1 Instrument Information in section 17 Instrument Setup amp Configuration 4 8 Install the Sensor Care must be taken to prepare the site for installation See section 16 Installation Procedure for details and watch VIDEO g SPO5 Installation and VIDEO SP04 Installation Preparation and
98. heat sink for thermal stability during the psychrometric measurement NOTE 4 the ambient temperature of the PSY1 can fluctuate within the normal range of diurnal cycles without affecting the measured water potential However the temperature within the chamber MUST remain stable throughout the duration of the 20 second measurement period Rapid temperature changes of even 0 1 C from the start of the measurement to the end of the measurement will cause noise and errors in the measurement of water potential To ensure a stable thermal environment the Psychrometer chamber MUST be wrapped in an insulating material that dampens the ambient thermal environment The chamber houses two chromel constantan thermocouples in series one located in the chamber air Thermocouple C and the second extending above the chamber well to contact the sample surface Thermocouple S The differential output from these two junctions AT is a measure of the temperature gradient between the sample Thermocouple S and the measuring junction Thermocouple C and allows the correction of the measurement of water potential for the influence of this gradient PSY1 Stem Psychrometer Manual Ver 4 4 Page 20 of 162 The PSY1 generates a Peltier cooling pulse of user definable duration but typically 10 second to cool Thermocouple C sufficiently to condense water on the thermocouple Watch Video 9 Principle of Operation for a visual example of this process The microvolt ou
99. hin 25 um wire The thermocouple surface will have a natural variation that may have more or less dimpling providing different physics for the condensation of water This is further impacted by the cleanliness of the thermocouple hence it is imperative that the chamber is cleaned prior to calibration NOTE 28 When the chambers are cleaned and calibrated at 25 C using fresh Molal calibrations solutions the calibration protocol reliably returns R of 0 999 to 0 9999 It is advisable to enhance the vapour seal between the faces of the chamber and the calibration disk holder with a small amount of silicon grease It is also helpful if calibration is carried out in a stable thermal environment or temperature controlled chamber Watch a demonstration VIDEO 17 Sealing the Calibration Lid to the Psychrometer to perform a calibration measurement PSY1 Stem Psychrometer Manual Ver 4 4 Page 74 of 162 16 2 Calibration Temperature Calibration is usually done at or corrected to 25 C Temperature correction for Psychrometric measurements is given by Corrected Reading Reading 0 027T 0 325 Equation 3 Where T is chamber temperature in C The calibration routine should be carried out in a temperature controlled chamber if possible However if you can only manage crude temperature control then this is often worse than none at all Rapid cycling of temperature caused by heating and cooling systems initiates transient gradients in the in
100. his is an inherent data backup and redundancy function 21 8 Data File Format The data file is automatically generated using the following format instrument serial number csv e g PSY1A1B2 csv The serial number not only uniquely identifies each instrument it contains specific information about the date of manufacture and production run Please provide the serial number to ICT International for all support inquiries The PSY1 firmware is Windows FAT 32 compatible This means that the data storage of the MicroSD card is written in fully complaint Windows File Allocation Table FAT format So any MicroSD card can be used in the Instrument As a result the MicroSD cards are Hot Swappable meaning it can be removed from the instrument and inserted into a USB port of a Windows PC using a USB card reader or shuttle and then reinserted to the instrument No closing down Ejecting or formatting is required Note 59 MicroSD cards can be purchased from any retailer There is no limitation that memory cards must be supplied by ICT PSY1 Stem Psychrometer Manual Ver 4 4 Page 148 of 162 22 Appendices 22 1 PSY1 Test Procedure 1 Place the PSY 1 in a controlled temperature environment preferably approx 25 C This specific temperature is not essential for testing purposes The main consideration is a generally stable temperature 2 Connect psychrometer chamber to PSY 1 3 Turn on the Instrument 4 Open PSY1 Software 5 Find Device
101. his is covered in detail in section diagnosing a dirty thermocouple Conversely badly contaminated and dirty psychrometers can easily be identified from visual Observation in some cases even without the use of a 20 x dissection microscope Photo 9 A heavily contaminated stem psychrometer in which the chamber well has been filled with vacuum grease and plant tissue or callus this type of contamination is clearly obvious from visual observation PSY1 Stem Psychrometer Manual Ver 4 4 Page 40 of 162 10 1 Cleaning routine The stem psychrometer requires a strong organic solvent to clean dirt and or organic matter that may have entered and contaminated the chamber and thermocouples The organic solvent will dissolve the contaminants but both the organic solvent and dissolved contaminants must be flushed from the chamber using distilled water Failure to do so will result in the dissolved contaminants precipitating out of solution as the solvent dries evaporates and the thermocouples being recoated with a film of contamination and not being cleaned The organic solvent recommended for cleaning the psychrometer is Chloroform CHCI This is a standard analytical reagent available in most laboratories however it is regulated under strict safety controls that may make it difficult to access and definitely difficult to transport safely in the field An alternative cleaning agent that may be substituted for Chloroform is electrical contact cl
102. iOl senec E VR RED EUG AHEAD ROS CHR APR R BOR 113 TSS SD Cara Pormabtlig sesenta uet aa ae oteted d ae tre boo ph EE 114 18 1 9 Instructions to reformat a MicroSD Card eeeeeeessseeeeeeen nennen 114 18 1 10 Format Check diries an a A S a NNA 114 18 1 11 File Name ENON coe o Pons o bate TE G 114 18 1 12 Serial INGA else RN p ERR a T R 115 18 1 13 KIC ON oM c CUNEO 115 18 1 14 ARP Serial 3 ces oat ee ve per dba adi mte ee ata td vadis bap ea E E 115 18 1 15 molut 115 18 1 16 B M RERO 116 18 1 17 APP VET e C 116 18 1 18 COM M pr v m 116 PSY1 Stem Psychrometer Manual Ver 4 4 Page 6 of 162 PSY1 Stem Psychrometer Manual Ver 4 4 18 1 19 EXEOMH ASU DOV ROREM Pr 116 18 1 20 Bat EV oascihu a Medstas pesas N tenu edt neces 117 18 1 21 SACS Sas c 117 192 RawijData Tdbussicsstednipu testati evis a a RD Sand 117 I9 db nosset Need UN MAI SEM UMEN IUE 119 15 233 Chamber temp aarnior tei victi Mete oues up ee pup tud Ip cse DIS LES LC LU DPI LoeE 119 1823 WE BUID ois itte dete A cE ee een Rain ore Idee E Ue eS ne eee 119 15 2 4 Measurement Stats usitas a Beo oto het medio beeen eae uuo ecce aoc Urbe de 119 18325 3ShoW Dig SnOStics ena Se PMatUM eu MM DNI DELI INE EDIDI ELE REDE DEAS 120 18 3 Measurement SESS tICS sci neto Diese o lori Pado ate sb atat citar Ist ATUM EL as 122 Measurement CODtrol ouem tes tinae ipei E E eau Loa UR Kap CURE d 123 19 1 Measurement MOU
103. ia USB Cable A micro USB cable is supplied for downloading and configuring the instrument It is a Standard cable in most computer stores The physical USB connection is the simplest method to download data form the PSY1 instrument 21 4 Via MicroSD card USB Adapter Alternatively the PSY1 can be downloaded by removing the Micro SD card and putting it in a USB cradle supplied by ICT and inserting to a USB port of a PC ICT use Microsoft FAT32 formatting so the card is immediately recognizable as a mass storage device when inserted to a PC with Windows OS and files can be dragged and dropped as normal The MicroSD card shuttle is a USB port adaptor or card reader The MicroSD card fits inside the reader so you can plug the MicroSD card directly into a USB port on the PC The full data transfer speed seconds for 2GB is then possible when downloading data If USB cable is used between the device and the PC then the speed is much slower minutes d jen n 1 qm uo i drum d Insert into USB port Photo 41 Micro SD Card Adapter inserted into the USB port of a computer PSY1 Stem Psychrometer Manual Ver 4 4 Page 147 of 162 21 5 Windows FAT 32 compatible Data is written to and stored on the MicroSD card in fully compliant Windows File Allocation Table FAT format What this means is that any MicroSD card can be used in the Instrument There is no limitation that all memory cards must be supplied by ICT This
104. ic mode applying necessary temperature correction PSY1 Stem Psychrometer Manual Ver 4 4 Page 22 of 162 6 4 Psychrometric equation A Psychrometric Wet Bulb Depression WBD is measured when a Peltier cooling current condenses water from the atmosphere of the chamber which subsequently evaporates and cools the thermocouple junction The raw Psychrometric Wet Bulb Depression is corrected for ambient temperature using an empirically derived algorithm It is then converted to water potential with a calibration slope and intercept derived for the instrument from a six point calibration protocol using solutions of known solute potential Molality Finally a correction for AT or the temperature gradient between the tissue and the measuring junction is applied Y WBD C Tc C3 CD CS AT k CF Equation 2 Where W Corrected Water Potential C Empirically derived temperature correction Constant C Empirically derived temperature correction Constant Cl Calibration Intercept CS Calibration Slope WBD Psychrometric Wet Bulb Depression uV Tc Chamber Temperature C AT Measured temperature difference between Thermocouple C and Thermocouple S uV k Chromel Constantan Thermocouple output C CF 41 Correction for AT MPa C 6 4 1 Psychrometric Wet Bulb Depression The Psychrometric Wet Bulb Depression is the temperature to which the Thermocouple C is cooled when water condensed from the chamber air i
105. icket for a Return Merchandise Authorisation Number RMA 8 and immediately return the chamber for repair together with a completed RMA Form and corresponding Service Desk ticket number Instruments returned without an RMA form WILL NOT BE RPAIRED Where the repair is urgent it may be possible to organise the dispatch of an exchange chamber to minimise the down time 19 2 1 Live Logging Interval The live data can be saved to a custom file extension lve on the Micro SD card This can be a file name of your choosing and saved to your preferred folder location on the computer Data can be logged at intervals between 1 60 seconds Once the required logging interval is chosen use the up and down scroll arrows or type the value directly into the field and click on the Done icon to commence logging I Live Logging Interval a elk Select lve mode logging interval 0 60 seconds CS seconds Digable Cancel Done Figure 76 Live Logging Interval Window for and setting Live Logging mode intervals or deactivating Live Logging Mode To stop logging in live mode click on the Select Live Logging Interval icon to bring up the Live Logging Interval window Measurement Control Measurment Made Live ww re mu LIFT 5 44 Select Live Logging Intera Update Measurement Mode Q Figure 77 Measurement Control Select Live Logging Interval i l Start Measurement PSY1 Stem Psychrometer Manual Ve
106. ide as this will raise the thermocouple up into a vertical position It should only be necessary to raise Thermocouple S into the vertical position Thermocouple S must be raised to the face of the psychrometer chamber so that it can make contact with the xylem surface in order to directly measure the stem temperature and thus determine dT Photo 8 Thermocouple S viewed from the side sitting just above the chamber surface PSY1 Stem Psychrometer Manual Ver 4 4 Page 39 of 162 10 Cleaning the Psychrometer The need for cleaning the stem psychrometer may not always be obvious from visual observation even under a 20 x dissection microscope The Stem Psychrometer consists of two very small welded thermocouples using very fine wire only 25 um in diameter This makes the sensor very sensitive to measuring water potential but equally as sensitive to dirt and even mild oxidation It is recommended that before starting any measurements you clean the thermocouples NOTE 10 This should even be done upon receipt of new instruments from ICT or at the commencement of a field campaign especially if they have been stored for any length of time WARNING NEVER store the stem psychrometers without first cleaning Diagnosing a dirty thermocouple that is not visually obvious is done by plotting the Peltier cooling curve and interpreting psychrometric plateau and the thermocouple response as it returns to zero microvolts within the measurement period T
107. ime say 5 seconds Peltier Cooling Curve 20 Time since end of cooling s Figure 90 Shows the characteristic response of a clean Thermocouple C The output response of Thermocouple C is in the range of 19 uV for a1 0 Molal solution the plateau of the psychrometric Wet Bulb Depression lasts until approx 10 seconds after the end of cooling and rapidly falls to zero the pre pulse zero reference and remains steady at this temperature indicating there is no thermal or electronic drift PSY1 Stem Psychrometer Manual Ver 4 4 Page 136 of 162 20 3 Peltier Cooling Curve Diagnostic Tool The decay of the Wet Bulb Depression as the output returns to zero reference i e the thermocouple warms back up to the initial starting temperature after having been cooled is indicative of the cleanliness of the thermocouple Dirt and dust silicon grease used to seal the chamber and contact with living plant tissues that can accumulate through general field use and oxidation of the thermocouples both through general field use and or poor maintenance during storage all cause the thermocouple response to be less sensitive and take longer to and be less likely to return to zero after a cooling pulse Peltier Cooling Curve Peltier Cooling Curve 20 Time since end of cooling s Figure 91 shows the characteristic response of Thermocouple C that requires cleaning Note the low output response of the Wet Bulb Depression in
108. ination had been cleaned water could fully condense on the surface of the thermocouple and fully evaporate from the thermocouple leaving it completely dry and rapidly returning to zero No microscopic beads of water remained trapped on the thermocouple by organic contaminants disrupting the evaporation process and causing a thermal Offset or interference Peltier Cooling Curve Peltier Cooling Curve 20 Time since end of cooling s Figure 7 the good characteristic response of a clean Thermocouple C CAUTION 1 Sometimes the process of cleaning can reposition thermocouples in awkward positions that make simple manipulations tricky when positioning Thermocouple S for measurement Be sure to take extra care and use a 20X dissection microscope to reposition the thermocouple See Handling the Instrument and adjusting thermocouples for detailed instruction to minimise the possibility of damage to the thermocouples PSY1 Stem Psychrometer Manual Ver 4 4 Page 48 of 162 10 3 Storing the Stem Psychrometers It is not always practical to clean the stem psychrometers after de installation whilst in the field However this does not mean that they can be left until you next need them for a future experiment They must be cleaned upon return to the lab and prior to storage Oxidation of the copper posts within the chamber of the psychrometer may affect the measured water potential If the chamber is not cleaned and the copper posts are corr
109. ion of Thermocouple S using a 20 x dissection microscope or a 10 x pocket hand lens if in the field If Thermocouple S requires adjustment follow the instructions in Chapter 9 Setup Procedure The stem Psychrometer is now clean and ready for deployment NOTE 12 a pre packaged pressurised can of pure moisture free compressed air is recommended to ensure sufficient pressure to drive out microscopic beads of water from around the copper posts and is a convenient tool in the field tee Cool BAIR JET SPRAY Photo 12 CRC Air Brush Compressed Air Photo 13 Dick Smith Air Jet Spray PSY1 Stem Psychrometer Manual Ver 4 4 Page 44 of 162 10 2 Diagnosing a Dirty Thermocouple Detection and diagnosis of a contaminated thermocouple is easily accomplished with the PSY1 in Manual mode Place a known water potential sample 1 0 Molal NaCl solution on a filter paper disk in the calibration lid of the Psychrometer Set the PSY1 to Manual mode and perform a measurement If the thermocouple is very dirty the measured result will clearly indicate a problem This can be seen in the Dialogue box where the results of the manual measurement are immediately displayed upon completion of the measurement The key factor to review is the Wet Bulb Depression If water had been able to be condensed on the thermocouple it would have cooled generating a uV output in the range of 19 uV for a 1 0 Molal solution In this example there is effectively no change from th
110. irements The instrument should be placed squarely onto the stem avoiding any sliding across the stem surface and firmly attached Typically finger pressure is sufficient to correctly tighten the clamp and ensure a vapour seal between the sample and the chamber well Excessive clamping pressure should be avoided as this may squeeze unwanted sap into the chamber and result in unreliable measurements Clamping pressure should be checked periodically especially on water stressed samples since stem diameters vary significantly in some species as they dehydrate Photo 32 a psychrometer attached to a cotton plant stem Silicone vacuum grease has been smeared across any exposed xylem The installation is now functional but requires thermal insulation to reduce the influence of rapid changes to ambient thermal gradients PSY1 Stem Psychrometer Manual Ver 4 4 Page 101 of 162 17 6 Sealing the Exposed Site Inert silicon grease stable under high temperatures e g Dow Corning vacuum grease should be applied to any exposed sapwood that remains after the attachment of the psychrometer This is necessary to reduce local evaporation and the possibility of inducing water potential gradients in the tissue Also apply some grease around the junction of the sample and stem psychrometer However before doing this it is important to test the integrity of the vapour seal between the psychrometer and the stem An imperfect vapour seal can be detected by dire
111. ive after each measurement PSY1 Stem Psychrometer Manual Ver 4 4 Page 72 of 162 Chamber Heating Chamber heating is performed to mitigate condensation if required IE occurs Immediately following completion of the measurement protocol Chamber heating duration Ame Chamber heating between 04 45 and 0315 Always allowed Update Chamber Heating Figure 34 Chamber Heating should be set only to operate within the early hours of the morning when conditions are assessed to be most conducive to condensation Note 26 the Live Mode function can be used to evaluate the heat ring down in the chamber to empirically set the temporal interval between heating and measurements for each installation Set the PSY1 to Manual Mode and activate Chamber heating Set the heating duration and update these settings to firmware Then start Live Mode logging and set the logging interval to 1 second Now when a manual is made the dT Chamber Temperature and Thermocouple C values will be logged every second during and after the measurement until logging is stopped This will record the effect of chamber heating on the Thermocouple output and the period of time required for this effect to dissipate can be determined This data can then be used to develop the specific chamber heating protocol for the experiment PSY1 Stem Psychrometer Manual Ver 4 4 Page 73 of 162 16 Calibration Calibration of the stem psychrometer is accomplished by preparing a
112. ke these solutions yourself using a sodium chloride distilled water and carefully measuring the salt amp water exactly on a minimum 4 decimal balance An instructional video is available on the ICT International web site and the CD shipped with this instrument Alternatively premixed calibration solutions can be purchased directly from ICT International or there distributor in your country NaCl Mass of NaCl Mass of Water Water Potential MPa Molality g g PSY1 Stem Psychrometer Manual Ver 4 4 Page 152 of 162 22 5 Osmotic Coefficients and Water Potentials of Sodium Chloride Solutions Water Potential J Kg 10160 10350 Bar 100 J Kg Lang A R G Osmotic Coefficients and Water Potentials of Sodium Chloride Solutions from 0 to 40 C 1967 Australian Journal of Chemistry 20 2017 23 22 6 Copper Constantan Thermocouple Conversion Chart MILLIVOLTS 20 0 787 1 194 20 5 1 610 2 035 40 PSY1 Stem Psychrometer Manual Ver 4 4 Page 153 of 162 22 7 Correction Factors Ambient Temperature Relationship MPa C Note 62 these correction factors are included in Firmware in the PSY1 and are automatically applied based on the measured chamber temperature for each measurement i 0 e H O Ioljo Ojo ao W NJ EY I O 8 555 8 518 8 480 8 469 I Ul 0 EY oO O e CO N OIO 8 432 8 406 8 399 8 395
113. lant Physiology 75 766 772 d Tyree Melvin T Fiscus Edwin L Wullschleger S D amp Dixon M A 1986 Detection of Xylem Cavitation in Corn under Field Conditions Plant Physiology 82 597 599 e Johnson R W Dixon M A and Lee D R 1992 Water relations of the Tomato during fruit growth Plant Cell amp Environment 15 947 953 f Edwards D R and Dixon M A 1995 Mechanisms of drought response in Thuja occidentalis L Water stress conditioning and osmotic adjustment Tree Physiology 15 121 127 g Edwards D R and Dixon M A 1995 Mechanisms of drought response in Thuja occidentalis L l Post conditioning water stress and stress relief Tree Physiology 15 129 133 h Chamberlain C P Stasiak M A and Dixon M A 2003 Response of Plant Water Status to Reduced Atmospheric Pressure SAE International 2003 01 2677 i Robinson S Dixon M A and Zheng Y 2007 Vascular blockage in cut roses in a suspension of Pseudomonas Fluorescens Journal of Horticultural Science amp Biotechnology 82 5 808 814 j FISHER Rosie A WILLIAMS Matthew LOBO DO VALE Raquel LOLA DA COSTA Antonio amp MEIR Patrick 2006 Evidence from Amazonian forests is consistent with isohydric control of leaf water potential Plant Cell amp Environment 29 151 165 k Lang A R G Osmotic Coefficients and Water Potentials of Sodium Chloride Solutions from 0 to 40 C 1967 Australian Journal of Chemistry 20 2017 23 PSY1 Stem Psychrometer Manu
114. le Contact ICT International for more information PSY1 Stem Psychrometer Manual Ver 4 4 Page 13 of 162 5 Description The PSY1 stem psychrometer consists of a psyhcrometer chamber calibration disk holder and an integrated standalone data logger with Windows Graphical User Interface GUI software for instrument configuration and data downloading A solar panel can be directly connected to the non polarised charging ports to trickle charge the internal battery for continuous field operation Photo 1 PSY1 Stem Psychrometer complete 5 1 Stem Psychrometer Chamber The psychrometer chamber is made of chrome plated brass to achieve a large stable thermal mass Two welded Chromel Copper and one Constantan Copper thermocouple are housed within the chamber The measurement is performed by passing a Peltier cooling pulse through the C or Chamber Thermocouple to generate a Psychrometric Wet Bulb Depression WBD This Wet Bulb depression is automatically corrected for temperature and processed using the slope and intercept of the specific calibration for the stem psychrometer to yield Stem Water Potential MPa AEN Photo 2 PSY1 Stem Psychrometer chamber PSY1 Stem Psychrometer Manual Ver 4 4 Page 14 of 162 5 2 Calibration ICT International does not supply the stem psychrometer with a factory calibration Calibration of the instrument can be performed by the user A calibration disk holder a comprehensive software calibra
115. le to receive manual entries typed from the keyboard of the computer Raw Data Measurement Protocols Calibration SO Card PC Logging Raw Data Measurement Protocols Calibration SD femp Logging Stop Calibration Mew Calibration Stop Calibration New Calibration bul j i 1 Head Calibration Head Calibration Natl Wet Chamber L orrected Nall Wet Chamber Corrected Molalty Bulb Temp wet Bulb Average Molalty Bulb Temp Wet Bulb Average Plot Against Plot Against a b Figure 49 a Calibration input cells are locked until they are opened by clicking the Edit calibration b cells change colour to white when Open PSY1 Stem Psychrometer Manual Ver 4 4 Page 84 of 162 16 6 2 Save Current Calibration to HDD Calibration data can be saved to the Hard Disk Drive HDD of the computer at any time by clicking on the Save Current Calibration to HDD icon This process should be performed after each data point is measured to ensure that no data is lost in the event of a software or OS crash Clicking on the icon opens a MS Save As Window that defaults to the directory C Program Files ICT ICT Stem Psychrometer cqs this directory can be changed to your preferred location Note 34 the calibration file should always be saved as the four digit Serial Number of the psychrometer being calibrated This ensures a tracking reference in the future Raw Data Measurement Protocols Calibration SD Card
116. ly intervals for between 3 to 5 days on the internal battery if you are not heating the chamber If you use a small 5 Amp hr external battery you could operate the PSY1 for a month before needing to exchange the external battery for a charged one All power is drawn from the internal battery regardless of any external source connected Hence trickle charging can occur over very long 27100 m low grade cable just so long as you are above 8 volts by the time you reach the instrument from the source As the internal battery is 4 2 V Lithium Polymer and inverts to 12V PSY1 Stem Psychrometer Manual Ver 4 4 Page 31 of 162 7 2 Connecting a Power Supply to the Instrument The unique power bus plug design was developed by ICT to simplify the electrical wiring process It minimises the need for custom tools in the field requiring only that the outer cable sheath be stripped back to expose the copper wire As shown below no other tools are required with all necessary components and fixings fully incorporated into the instrument design Retaining straps ensure the power bus plugs do not separate from the instrument when removed from the power bus during wiring preparation and connection of external power Important Do not connect external power until the final step Bend the stripped wires back over the end of the ICT bus plug Remove both ICT Bus plugs from Important Seal the cable against either end of the sensor water ingress by tighte
117. me for extraordinary gradients caused by the heater to dissipate before attempting a measurement See Measurement Protocols for details on the setting of the chamber heating protocol PSY1 Stem Psychrometer Manual Ver 4 4 Page 27 of 162 6 10 Osmotic Potential Osmotic potentials can be measured on extracted sap samples or destructively sampled leaf tissue or leaf discs These measurements can be made in the lab or in the field Samples are placed in the calibration lid of the PSY1 stem psychrometer The psychrometer chamber is housed in the Osmotic Potential Insulator OPI to provide a thermal insulating jacket around the chamber This eliminates introduction of thermal gradients caused by a need to handle the chamber to load samples and provides a stable insulated thermal buffer from ambient temperature gradients within the surrounding environment This enables a samples Photo 4 PSY1 Stem Psychrometer amp Osmotic Potential Insulator Osmotic potential measurements are typically performed in a manual process Using the Graphical User Interface GUI the PSY1 provides the user with a Live mode or a Manual mode to facilitate osmotic potential measurements 6 10 1 Collecting an Extracted Sap Sample An abraded leaf disc or filter paper disc saturated with extracted sap exudates from a suitably prepared sample using a freezing and physical disruption protocol to separate the symplastic fluid from the cells of the leaf are
118. means any MicroSD card purchased anywhere in the world or any MicroSD card pulled out of a Digital Camera or mobile phone can be inserted directly into the Instrument for immediate compatibility and use Similarly any MicroSD card used in the PSY1 can be removed and placed into a Camera or phone and MOST importantly any Windows PC and is automatically recognised and the data can be copied across through Windows Explorer to any file location on the PC This means data can be manually downloaded from the instrument by an unskilled or semi skilled person who removes the MicroSD card from the Instrument and inserts another MicroSD card The PSY1 automatically generates a new data file and continues logging uninterrupted while the data is returned to the office for download from the MicroSD card 21 6 Micro SD Card Memory Capacity The memory capacity of the MicroSD card is 2GB In practical terms the PSY1 can log all diagnostic measurements relevant to the calculation of water potential and all Extras or fundamental measurement parameters such as dT Wet Bulb Chamber temperature battery voltage and charging current at a 10 minute logging interval for 443 years 21 7 Renaming data files When data is downloaded the data file can be renamed by adding an incremental number to the file extension such as filename 001 instead of filename csv and the data is then left on the MicroSD card as an off site back up of the master data set stored in the office T
119. meter od P Get Latest Data je Plot 45 Select Live Logging Interval Start Measurement A mm m Bde Statistics Measurment Mode z Statistics shown below are calculated based on measurement results INFO Device disconnected captured by the ICT PSY utility software These statistics are not stored on INFO Measurement Mode Updated OK the PSY sensor interface Difference Max Min Av Connected to ICT PSY Batt 4 06 V Port COM6 Device Date 05 11 2010 Device Time 24hr 18 28 Figure 74 PSY1 Software set to Live Mode displaying real time values measured from the Thermocouples in the psychrometer gt ConnecttoPSY Disconnectfrom PSY CommecttoPS Disconnect from PSY Raw Data Measurement Protocols Calibration SD Card PC Logging Raw Data Measurement Protocols Calibration SD Card FE Logging uuu M iratis Misael di aL ul Chamber Temp Therm C dT 1 Chamber Temp Therm C w 2782 dest W I 133838 Ju 2782 eat T n a b Figure 75 a shows an expected output from Thermocouple C when the Thermocouple is intact and in working order b Shows the open circuit response of a broken Thermocouple S This chamber requires repair by ICT International PSY1 Stem Psychrometer Manual Ver 4 4 Page 125 of 162 Note 55 Please contact ICT International on the Service Desk via our web site www ictinternational com and submit a t
120. n 19 5 Status Bar The status bar is located along the bottom of the PSY1 GUI and provides basic information about the operational status of the instrument Connected to ICT PSY Batt 4 06 V Pork COME Device Date OS 11 2010 Device Time z4hr 18 28 Figure 85 PSYI Software Status bar 19 5 1 Connection status e Disconnected e Connecting e Connected to ICT PSY PSY1 Stem Psychrometer Manual Ver 4 4 Page 132 of 162 19 5 2 Batt Displays the internal battery voltage of the instrument both prior to connection and once connected Prior to connection it provides a very useful diagnostic tool should the PSY1 fail to connect due to a low internal battery voltage 19 5 3 Port Displays the active COM port being used by the instrument associated with the open Software window multiple instruments can be connected to a PC simultaneously on different COM ports by opening multiple software windows 19 5 4 Device Date The current date of the instrument is displayed This can be set manually by the user or synchronized with the PC Date amp Time See section PSY Menu 19 5 5 Device Time The current time of the instrument is displayed This can be set manually by the user or synchronized with the PC Date amp Time See section PSY Menu 19 5 6 Help Menu 19 5 6 1 About The About Splash Screen displays the Software s e Product name e Product Version e Release date e The ICT Web site link www ictint
121. n DOW CORNING i high vacuum grease Dow Corning Syringe with the grease et T Vacuum Grease to create a vacuum seal For holding the PSY1 chamber to the large clamp Large Clamp Screws The plastic clip lock tool box protects and stores everything you need for a successful installation Plastic Clip Lock Tool Box PSY1 Stem Psychrometer Manual Ver 4 4 Page 155 of 162 Use the wash bottle filled with distilled Wash Bottle water to wash off the installation area Use your wipes to make sure the area is Kim Wipes completely dry you queue 1 may need to rub vigorously Use the syringe filled with Silicon grease to 10ml Offset smear around the gpn sasaszn 1 Syringe whole of the wound a 8 thus creating a vapour seal Use the polyester e Insulation to secure the PSY1 Stem Psychrometer after Installation Polyester Insulation The razor blade is used to remove bark and excess tissue to create an excessive flat area Single Edge Razor Blades Reversible Philips EL PETNOHVEE Head Flat screwdriver PSY1 Stem Psychrometer Manual Ver 4 4 Page 156 of 162 Small Clamp Screws Roll of Aluminium Foil Wire Strippers Psychrometer User Manual amp Software USB Cable 30 Rubber Bands Stainless Steel Tweezers PSY1 Stem Psychrometer Manual Ver 4 4 For holding the PSY1 chamber to the small clamp Wrap the foam with aluminium foil to get a
122. n diameter This makes the sensor very sensitive to measuring water potential but equally as sensitive to dirt and even mild oxidation It is recommended that before starting any measurements you clean the thermocouples following the instructions in section 10 Cleaning the Psychrometer and watch VIDEO SP12 Cleaning 4 3 Install the PSY1 Software amp USB Driver Insert the supplied CD into the computer The CD will auto run to present a menu Choose install software see section 11 Software amp USB Driver Installation for details 4 4 Turn the Instrument On The PSY1 can either be turned on manually by pressing the power button see section 12 Turn the Instrument On or automatically by connecting an external power supply see section 7 Charging Powering the Instrument 4 5 Connectto the Instrument Connect the USB cable to the instrument The PSY1 will automatically be detected by the computer as with any USB device Double click the PSY icon on the desk top to open the software and click the icon Connect to PSY then search for and select the named instrument from the connections Window See section 13 Communications Connect to the Instrument for details PSY1 Stem Psychrometer Manual Ver 4 4 Page 12 of 162 4 6 Setthe Measurement Protocols Each installation will be different if only slightly For this reason measurement protocols such as the Sensor Calibration slope and intercept Peltier Cooling Pulse options or C
123. n progress Note 48 When the instrument is in Live Mode values are constantly displayed in real time refreshed at the sampling rate of the instrument 10 Mhz or every 0 1 second Each measurement parameter displayed on the Raw Data tab is explained in detail below PSY1 Stem Psychrometer Manual Ver 4 4 Page 118 of 162 18 2 1 dT Displays the difference in temperature dT measured in uV between the Thermocouple S and Thermocouple C In the manual mode dT will be measured initially at the commencement of the measurement process and this value remains on display until the completion of the measurement Note 49 In the Live mode the dT is continuously monitored and updated 18 2 2 Chamber Temp Is the measured temperature C of the entire psychrometer chamber body The measurement is made by a Copper Constantan thermocouple located within the insulated base of the psychrometer chamber It is representative of the ambient conditions under which the measurement is made The chamber temperature measurement is made and subsequently displayed after the Peltier cooling pulse and psychrometric wet bulb measurement has been made Note 50 In the Live mode the Chamber Temp is continuously monitored and updated 18 2 3 Wet Bulb Is a direct measurement uV of Thermocouple C within the chamber of the psychrometer Thermocouple C is initially the Dry Bulb and then following condensation of water vapour via Peltier cooling the Wet Bulb
124. n the chamber well in solution This contaminated solution must be flushed with distilled water prior to it evaporating b Then using a wash bottle of distilled water immediately rinse away the dissolved contaminants by squirting a steady stream of water into the chamber well rinsing continuously for approx 3 5 seconds c Next use a Kim Wipe or other such lint free tissue and place a corner of the tissue in the outer edge of the chamber well This will wick the bulk of the water up out of the chamber well WARNING 9 Be extremely careful not to touch the thermocouples with the tissue and do not attempt to rub the tissue within the chamber The intention is merely to absorb the bulk of the free water not to completely dry the chamber well d Finally blow dry with a controlled stream of compressed air 20 to 30 psi The drying phase is important as residual water must be removed from the chamber well Stubborn drops may reside around the copper posts and sustained streams of compressed air may be required to remove all the water PSY1 Stem Psychrometer Manual Ver 4 4 Page 43 of 162 This cleaning process may be required to be performed several times to achieve a thorough cleaning of the stem Psychrometer depending upon the severity of the contamination Once satisfied that the stem Psychrometer is clean connect the unit to the PSY1 and perform a verification test Appendix 1 At this point you should also visually check the posit
125. ng monitored It may be necessary to trial a range of chamber heating durations between the ranges of 15 seconds to 2 minutes until the ideal protocol for the prevailing conditions is determined PSY1 Stem Psychrometer Manual Ver 4 4 Page 71 of 162 Note 25 the appropriate chamber heating protocol is one which maintains conditions such that condensation will not occur on the chamber walls i e the chamber is warmer than the sample Chamber heating can be continuously employed but this has the potential to cause artificial drying of the stem if employed when undesirable temperature gradients are not present As a broad guideline the most likely period for condensation to occur inside the chamber due to the chamber being colder than the stem is between 5 00AM to 10 00AM Chamber Heating Chamber heating i performed to mitigate condensation if required IE occurs immediately following completion of the measurement protocol Chamber heating duration Chamber heating between Always allowed Figure 32 Chamber Heating Duration drop down box heating duration can be set from 15 seconds to 10 minutes Chamber Heating Chamber heating rs performed to mitigate condensation if required It occurs immediately following completion of the measurement protocol Chamber heating duration 4m Ww Chamber heating bet weer ooo and anno 4 Always alowed 4 Update Chamber Heating Figure 33 Chamber Heating can be set to be always act
126. ng window then the logging interval should be reviewed PSY1 Stem Psychrometer Manual Ver 4 4 Page 68 of 162 Peltier Cooling Curve Peltier Cooling Curve 6 Second wait time the plateau is very low and flat No obvious drop off 6 and return to zero due to the use of a 10 second cooling at the Wet end 4 of the range uy 2 4 0 10 20 30 40 Time since end of cooling s Figure 28 Peltier cooling curve with an excessive cooling time relative to the water potential of the sample resulting in a much longer time required for Thermocouple C to return to zero reference This sample was taken on Sequoia sempervirens Coast Redwood and the measured water potential 0 76 MPa was simultaneously verified against a Scholander pressure bomb 0 73MPa It is important to note that the length of the Peltier cooling pulse does not affect the measured water potential It will only affect the duration of the Psychrometric Wet Bulb depression This is best demonstrated by performing a calibration measurement using a 1 0 Molal solution on a filter paper placed in the calibration lid Place the PSY1 in Manual mode and set the Peltier cooling time to 5 seconds Then commence a reading For a clean psychrometer the response will be in the range of 19 uV and the duration will be approximately 10 seconds before a sharp drop back to zero reference Peltier Cooling Curve Peltier Cooling Curve 6 Second wait which falls midway on
127. ning the end of the plug Repeat for second bus plug Unscrew the end of the plug 1 to 2 turns Insert the ICT bus plugs into the diiit the Bus plug endcap of the sensor The plugs sealing cap can be inserted in either polarity and will click when seated into position Insert either polarity of the external power source cable n Strip a maximum of 15mm from the end of the cable External power options 1 12V Solar panel only 2 12V Solar panel and battery 3 12V DC power supply Pull the cable back so only that the stripped wires protrude Connect the power cable to the from the ICT bus plug external power source PSY1 Stem Psychrometer Manual Ver 4 4 Page 32 of 162 7 3 Connecting Power Directly via Solar Panel secs UD e i m reve EH Solar Panel PSY1 Stem Psychrometer Manual Ver 4 4 Page 33 of 162 7 4 Connecting Power via External 12V Battery E n External 12V Battery PSY1 Stem Psychrometer Manual Ver 4 4 Page 34 of 162 7 5 Connecting Power via External 12V Battery and Solar Panel na External 12V Battery Solar Panel PSY1 Stem Psychrometer Manual Ver 4 4 Page 35 of 162 7 6 Sharing an External 12V Battery and Solar Panel via Daisy Chaining f S V 3 S y PSY1 PSY lar Regulator Solar Regulato pad Solar Panel E J iv wi Dk A External 12V Battery PSY1 Stem Psychrom
128. nt is stored in the header line of the data file PSY1 Stem Psychrometer Manual Ver 4 4 Page 112 of 162 18 1 3 PSY Serial No Enter the individual serial number of the stem psychrometer chamber here Each Psychrometer is labelled with a unique 4 digit number This enables the user to generate a specific custom calibration for each chamber The calibration information is stored on the internal Micro SD card under the 4 digit serial number of the chamber located within the psycal folder 18 1 4 The X Entries in these fields can de deleted by clicking on the x 18 1 5 Update Instrument Information Clicking this icon saves your changes to non volatile RAM so your settings remain in memory and active even after disconnecting from the PSY1 Note 42 whenever any of these 3 fields are updated a new header line is inserted into the data file This provides a tracking mechanism by which columns of processed data that can be logged such as water potential can be referenced to the data and calibration slope amp intercept used to automatically calculate the data 18 1 6 SD Card The status of the SD card is displayed If a SD card is inserted and functioning correctly it will display SD OK SD CARD SL QE Download Data Figure 55 SD Card Status amp Download Icon If the SD card is removed or not inserted the message NO CARD is displayed Note 43 it is possible to think you have pushed the card in but failed to have it click in
129. nt values Set Scale to Default Figure 92 Windows Plot options 20 3 2 Copy The graph can now be pasted into a word processing document such as Microsoft Word for inclusion in reports Image copied to clipboard Figure 93 Image copied window 20 3 3 Save Image As The graph can be saved as an independent image in a range of image formats most typically JPG for inclusion in reports or other media PSY1 Stem Psychrometer Manual Ver 4 4 Page 138 of 162 Savein C3 ICT Stem Psychrometer ja SHICT jpg My Recent Documents Desktop My Documents 43 My Computer File name Peltier Cooling Curve x My Network Save as type Jpeg Format ipg A Figure 94 Save As window 20 3 4 Page Setup Provides access to the printer s page setup settings to configure the printer for printing directly to paper Page Setup 184 210 297 mm Source Auto Select Onentation Margins millimeters Portrait Left 10 Right o Landscape Top 10 Bottom 10 Figure 95 Page setup window 20 3 5 Print Provides access to the Printer for printing a copy of the graph to paper PSY1 Stem Psychrometer Manual Ver 4 4 Page 139 of 162 Printer Status Type Lexmark TB42 where P_10 1723 40 200 Comment Print ta file Print range Copies All Number of copies 1 gH ok _ Cancel SO n l iil Figure 96
130. ntegrity and cleanliness of the thermocouple See diagnosing a dirty thermocouple Run a manual measurement on this solution first and plot the Peltier cooling curve before starting the calibration If the plateau is not in the general range of 17 20 uV for about 10 seconds then falls sharply to the zero reference and remains there then it is advised that the psychrometer be cleaned before proceeding with the calibration Always good to know this before performing a calibration 16 4 3 Selecting the Calibration Range Click on the use button corresponding to the calibration solution you have placed in the psychrometer calibration lid This measurement range is now active denoted by the subtle change in colour of all the input cells in that row Raw Data Measurement Protocols Calibration 5D Card PC Logging Stop Calibration New Calibration v Head Calibration Cal5H Device SM Comment ICT Demo Calibration M acl Wet Chamber Corrected Molality Bulb Temp Wet Bulb Average clear clear clear Plot Against Nothing d Calibrate Figure 37 selecting the calibration range PSY1 Stem Psychrometer Manual Ver 4 4 Page 77 of 162 16 4 4 Start Measurement Click the Start Measurement button and a measurement is commenced Upon completion of the measurement the fields will automatically be populated with the relevant data l Wet Bulb Depression ii Chamber Temp
131. ntil the board is off Note 24 If power is applied to the external inputs during the power down sequence power down is aborted and the unit will reinitialise PSY1 Stem Psychrometer Manual Ver 4 4 Page 65 of 162 15 Measurement Protocols The Measurement Protocols tab is where the majority of the configurations settings for the PSY1 are made E ICT Stem Psychrometer Fie PSY Help Instrument Information Hame PSY1 User Manual W arming and heating protocols are manually controlled in manual measurement mode Comment Armidale NSW Australia ee ee Current Calibration Serial No Slope PSY Serial Ho 1415 PSY0B312 UV MPa 4 Update Instrument Information ad i L SE Meesi User Manual Example uv Serial Humber l PSY0B312 1 A toasoe APP Ver R1 4 9 COM Ver R1 3 9G Measurement Options External Supply External supply connected v Cooling Time 5s v Waiting Time Bs v ET v Internal Battery 4 02 V Status charging Reverse Peltier warming Measurement Control Thermocouple warming is performed before a measurement takes place to nee nna Me ensure a dry measuring junction Manual i Warming duration Disabled v Wait before measurement 15s 4 Update Warming Protocol Chamber Heating Chamber heating is performed to mitigate condensation if required It occurs M immediately following completion of the measurement protocol 29 50 Slope and Intercept Updated OK 29 50 Please Wai
132. oded the psychrometer may require factory repair Corrosion is indicated by the green colouration on the copper posts It may be necessary to make the observation of this corrosion using a 20X microscope to be sure that the electrodes are not corroded and are suitable for use Photo 16 Corroded Copper posts and heavily contaminated psychrometer chamber well with broken thermocouple DO NOT store a stem psychrometer that looks like this Return it immediately to ICT for repair or replacement WARNING 10 Failure to clean the psychrometers after use and prior to storage WILL result in damage to the very fine 25 um wires of the thermocouples and result in the instrument needing to be returned to ICT for factory repair PSY1 Stem Psychrometer Manual Ver 4 4 Page 49 of 162 It is imperative that prior to storing the psychrometers you repeat the full cleaning process ensuring that they are dry before sealing the chamber Use a small smear of vacuum grease on the mating surface of the chamber and the calibration lid for a good air tight seal for storage a Then use the label tape to provide a physical seal around the mating join of the chamber and the calibration lid b Use a 30 rubber band wrapped over the chamber from one handle of the calibration lid to the other to provide a second physical restraint for the calibration lid c Finally wrap the psychrometer in a brown paper bag and store in a dry safe and secure location ready for the nex
133. oduce an unknown error in measurements Generally this problem can be spotted before it seriously affects interpretation of measurements NOTE 8 If a gradient favouring condensation on the chamber walls persists i e a negative gradient from Thermocouple C to Thermocouple S then measurements of apparent water potential will tend to rise and approach zero and not vary much between measurements When it is obvious that this has occurred remove the instrument clean and reinstall it Under experimental conditions which favour undesirable temperature gradients such as the cool early hours of the morning before sunrise through until mid morning the heater can be used to mitigate these problems It is a 12 volt DC resistive heater embedded into the back of the psychrometer chamber The heating protocol can be adjusted by the user and is automatically controlled by the PSY1 The exact protocol must remain a subject of trial and error depending on the specific conditions experienced However a reasonable approach is to routinely pulse the 12 volt heater for periods of 15 seconds to 1 minute between measurements immediately following a measurement to allow sufficient time for the heat introduced to the chamber to dissipate and return to equilibrium before the next measurement The appropriate protocol is one which maintains conditions such that condensation will not occur on the chamber walls i e the chamber is warmer than the sample Allow enough ti
134. of time under the same stable environmental conditions A full 6 point calibration can take 6 hours allowing a full hour of thermal equilibration time between the measurements of each data point This may not always be practical so an option to manually edit the calibration is included The intention of this feature is to allow outlying data points that are of concern to a calibration to be checked and remeasured without the need to repeat the whole calibration Note 33 the integrity of a calibration is imperative to getting good accurate water potential data This function should not be used to modify individual points of an existing or old calibration in isolation It should only be used to check individual points during a full calibration run should there be any doubt over the accuracy of an individual data point PSY1 Stem Psychrometer Manual Ver 4 4 Page 83 of 162 16 6 1 Edit the Calibration When a new calibration is started by default the calibration input cells are locked signified by the cells being greyed out Figure 35 a This is to ensure only directly measured values from the psychrometer can be automatically entered immediately following each calibration measurement To edit a calibration you must first open the input cells of the calibration interface This is done by clicking on the edit the calibration icon After clicking the icon the cells change from being greyed out to white signifying that they are open and ab
135. olution Watch a demonstration VIDEO 18 detailing the components used in the construction and use of a simple calibration chamber for psychrometers PSY1 Stem Psychrometer Manual Ver 4 4 Page 75 of 162 16 4 Calibration Protocol Prior to attempting a calibration of the psychrometer for the first time it is recommended that you watch the VIDEO 19 calibration protocol that clearly details all the practical steps involved in the successful calibration of the PSY1 Stem Psychrometer An additional Video 20 demonstrates the software calibration function to initate a measurement and process the calibration data The calibration routine is designed to be semi automated and all inclusive within the PSY1 software from making measurements of calibration solutions to plotting the data generating a slope and intercept and storing the calibration in the firmware of the PSY1 Instrument for real time data processing 16 4 1 Start Calibration To begin a calibration start by opening the software and connecting to the PSY1 instrument Then click on the Start Calibration button the software is now in calibration mode and you will only be able to perform a calibration ICT Stem Psychrometer m c i File PSY Help ConnecttoPSY Disconnect pgr Tm X Power Dom PS Instrument Information Hame ICT FESYCHROMETER PSY Serial Ho 1218 x MEN See NaCl Wet Chamber Corrected 4 Update Instrument Information Mollit E Temp et Bulb Average SD
136. om a number of commercial outlets Whilst these are all intended for the same basic purpose that being to clean electrical contacts leaving no residue for high electrical conduction they utilise a variety of organic solvents at varying concentrations Therefore not all electrical contact cleaners will perform to the same level of efficacy in cleaning the stem psychrometer ICT has evaluated a range of Electronic Contact Cleaners and provided a list of recommended options Appendix 22 2 Electronic Contact Cleaners lists manufacturer web sites and MSDS links to enable you to source a cleaner locally WARNING 7 Do not use a De greaser Spray or a contact cleaner that is oil based NOTE 11 Not all electronic cleaners may be available in your country VIDEO 13 Watch how to clean the psychrometer using Electrical Contact Cleaner a In an open well ventilated area preferably outdoors invert and hold the psychrometer chamber at 45 to the ground facing away from your body Shake the can well following the manufacturer s directions and spray a steady stream of electronic contact cleaner into the chamber well for approx 2 seconds ensuring the chamber well is fully saturated Repeat this process at least twice leaving the chamber well fully saturated WARNING 8 the physical pressure of the propellant used in the electronic cleaner will aid in dislodging contamination but will not fully remove the dissolved organics that will invariably remain i
137. ometer for direct measurement of osmotic potential 5 5 Measurement of Stem Water Potential The stem psychrometer measures the psychrometric wet bulb depression and ultimately the stem water potential of the plant and can be used in situ on the stem or leaf of a plant or on detached stems or leaves for dry down experiments or pressure volume curves PSY1 Stem Psychrometer Manual Ver 4 4 Page 15 of 162 5 6 Measurement of Leaf Water Potential Stem water potential measurements can also be performed on a prepared and insulated leaf in situ on the plant The leaf must be bagged or insulated from direct solar radiation and thermal gradients This of course shuts down photosynthesis meaning the water potential is no longer that as seen by the specific leaf rather the leaf effectively becomes a manometer to the plant The leaf is still hydraulically connected to the plant hence the stem water potential and that of the leaf come to hydraulic equilibrium This technique has been successfully used on a range of plant types Shackel K Theoretical and Experimental errors for In situ Measurements of Plant Water Potential Plant Physiology Vol 75 1984 Please contact ICT for more information 5 7 Measurement of Osmotic Potential Using the calibration lid the PSY1 can also be used to measure destructively osmotic potential MPa An abraded leaf disc or filter paper disc saturated with extracted sap exudates from a suitably prepared sample using
138. oprocessor chips to warm them to 20 C which is the minimum international standard operating temperature for silicon chips and microprocessors to operate at NOTE s whilst the instrument can operate at these extremes it is unlikely that the plant will PSY1 Stem Psychrometer Manual Ver 4 4 Page 18 of 162 6 Theory 6 1 Stem Water Potential Total water potential is the measure of the plants ability to interact with the environment It consists of four basic components Y Tp II T g Equation 1 Where W Total Water Potential Tp Turgor Pressure N Osmotic Potential T Matric Potential G Gravity The PSY1 Stem Psychrometer is designed to measure water potential with due consideration of ambient temperature and temperature gradients 6 1 1 Turgor pressure Is the outward pressure that occurs in a plant cell when the cytoplasm and vacuoles or membrane bound tissues fill with water and the cell membrane pushes against the cell wall The more water within the cell wall the greater the osmotic pressure Turgor pressure and osmotic potential typically dominate the total water potential of the plant and form the basis of the measurement made by the stem Psychrometer 6 1 2 Osmotic potential Osmotic potential is the result of dissolved solutes in membrane bounded tissues of a plant It is possible to measure this component of total water potential independently on samples from frozen or crushed plant tissue usually leaves This is c
139. ou Start a debug file and finishes when you Stop the Debug File or close the software The file is saved as a txt file that can be emailed to ICT engineers for analysis and trouble shooting ICT Stem Psychrometer d File PSY Connectta PSY Disconnect From PSY Help About Check For Updates Support j Create Support Lag x Start Debug File l l INTERNATIONAL PSYCHROMETER INTERFACE Product Version 2 0 5 4 Release Date 16 08 2012 Figure 87 Help Menu Support Options Create Support Log amp Start Debug File PSY1 Stem Psychrometer Manual Ver 4 4 Page 134 of 162 20 Peltier Cooling Curve During each measurement Thermocouple C is measured at a 10 Hz frequency for 30 seconds resulting in 300 readings per Peltier cooling pulse A two second running average filter is applied to the output to account for any electrical noise This data is then stored in RAM of the PSY1 In the manual mode this data can be recalled after each reading and immediately graphed The 300 raw data points for each Peltier cooling pulse can also be logged to a separate data file rdf csv This is configured through SD Card Logging Options via the PSY menu 20 1 1 Get Latest Data This icon reads the raw data points from internal RAM and makes them available for plotting on screen in the PSY1 software The Peltier cooling curve for the last measurement taken can be recalled and plotted Plot Peltier Cooling C
140. overed in more detail in section Osmotic Potential 6 1 3 Matric Potential Matric potential is defined as the energy required to extract water from a porous medium to overcome capillary and absorptive forces and is usually overwhelmed by osmotic potential and turgor pressure as a component of total water potential 6 1 4 Gravity In most plants gravity has a negligible effect but in trees of suitable height such as Redwood Sequoiadendron giganteum gravity can have a significant affect as demonstrated by figure 1 below in which the PSY1 measured stem water potential at 88m above ground level at the top of a 91 m Redwood tree The effect of gravity is shown by the night time recovery in stem water potential being offset by approx 0 90 MPa due to the contribution of gravity being equal to approx 101 9m head pressure MPa PSY1 Stem Psychrometer Manual Ver 4 4 Page 19 of 162 Baradur Tree Top West Psychrometer A601 VAM Figure 1 5 daily cycles of water potential measured with ICT psychrometer on a branch at about 88 meter height in a 91 meter tall Sequoiadendron giganteum At Whitaker s Forest California during the period Aug 13 Aug 17 2010 Unpublished Data Courtesy George Koch Northern Arizona University 6 2 Psychrometric measurement Each measured parameter in the psychrometric equation is directly measured by the PSY1 Stem Psychrometer The stem psychrometer is constructed of chromium plated brass to provide a large
141. placed in the calibration lid Wrap the leaf in a foil envelope and include a filter paper disk which will become saturated with the expressed cell contents Place in liquid Nitrogen to freeze then crush it in a vice to physically and mechanically disrupt the cell walls Place the saturated filter paper disk in the psychrometer calibration lid and measure the osmotic potential following thermal equilibration stabilization of the psychrometer chamber PSY1 Stem Psychrometer Manual Ver 4 4 Page 28 of 162 very rapid equilibration time between a b Photo 5 a the psychrometer chamber mounted inside the Osmotic Potential Insulator OPI and b loading a filter paper disc soaked in an extracted sap solution to measure osmotic potential PSY1 Stem Psychrometer Manual Ver 4 4 Page 29 of 162 7 Charging Powering the instrument The PSY1 is a stand alone instrument designed for long term deployment in remote areas for continuous unattended logging applications Each instrument has an internal 4 2V 800 mA lithium polymer rechargeable battery The microprocessor is a low power chip and the instrument functions below 4 V using only 3 mA in general operation An integrated inverter provides the 12V supply to perform measurement tasks specific to the Psychrometric principle as required At the heart of the instrument is a very sophisticated charging circuit that features a non polarised two wire power bus This eliminates the chance of d
142. ple C b dT should be close to 0 uV same as for the live test especially if you have not handled the chamber c Thermocouple C should again be around 0 6 uV and this is used as the electronic Dry Bulb offset EDBO d Chamber temp should remain the same e After the Peltier cooling the Wet Bulb Depression Thermocouple C should reach a maximum value in the range of 19 uV using the 1 0 Molal solution and then drop to exactly zero after the measurement 13 Click on the Get Latest Data 1con then plot the graph of the Peltier cooling curve 14 The graph should exhibit the characteristic curve of a plateau of approx 19 uV commencing on the graph at 4 5 seconds after Peltier cooling finishes The plateau should last until approx 10 seconds after cooling and then sharply drop to zero Once back at zero it should remain until the end of the measurement recording period of 40 seconds after the end of Peltier cooling Note 60 This long drawn out measurement period is to allow the capture of diagnostics at high water potentials close to zero which hold the moisture from the wet bulb depression much longer or dirty thermocouples that slowly drift back to zero or in fact never reach zero 15 Repeat 3 manual measurements and verify using the statistics bar in the utility software that the measurements remain stable within at worst a few bars from max to min Water potentials A 1 0 molal solution should return a water potential of 4 64 MPa
143. r 4 4 Page 126 of 162 Then click the Disable icon to reset to zero seconds and click Done Alternatively use the scroll arrows to adjust the seconds to zero Logging is now stopped but the instrument remains in live mode and the live display is still active E Live Logging Interval Sel Ed Select live mode lagging interval D B secorids D mi seems ee Cancel Done Figure 78 Live Logging Interval Window to deactivate Live Logging Mode Note 56 the instrument uses more power when set to Live mode It is recommended that when using Live Mode for extended periods you should connect an external power source to charge the internal battery Warning 16 Never disconnect the instrument while in Live mode As the instrument will continue to use power and drain the internal battery unnecessarily It may also cause the internal battery to become completely discharged When external power is connected and the battery is recharged above the hibernation mode the Live mode will automatically begin to drain power making it impossible to fully recharge the internal battery PSY1 Stem Psychrometer Manual Ver 4 4 Page 127 of 162 19 2 2 Live Data file Below is an example of a Live Data data file The lve file extension is used for differentiation purposes only The Actual file format is a Comma Separated Values CSV file that will automatically open in Excel or Sap Flow Tool SFT1 Analysis software The da
144. r and fixing on the clamp Be sure that Thermocouple S which is to be in contact with the sample is extended to the face of the chamber well by gently pushing it from one side or the other rather than grabbing it with forceps and pulling it Thermocouple S only needs to be just at the surface and not extended beyond the face of the chamber A Video 23 demonstrating the Adjustment technique recommended to position Thermocouple S should be watched prior to attempting this task for the first time WARNING 13 NEVER grab or pull the thermocouple with forceps Any tensile force applied to the thermocouple will break the tiny wires Thermocouple S is much longer than Thermocouple C which is easily identified when viewed under a 20X or better dissection microscope In addition to the visual difference in length of the Thermocouple wires Thermocouple C is located adjacent to the psychrometer cable and Thermocouple S is located distant to the psychrometer cable C Calibration disc holder E Stem Hyd Photo 31 Location of Thermocouple C amp Thermocouple S and Calibration disc holder PSY1 Stem Psychrometer Manual Ver 4 4 Page 100 of 162 17 5 Instrument Attachment Orientate the psychrometer chamber so that the long axis of the oblong chamber well is running axially along the plant stem When a suitable site is prepared the psychrometer can be attached using the clamp provided or some customized variation depending upon the requ
145. r in the Dialogue box and the default calibration will be loaded automatically 10 21 04 ERROR Calibration file doesn t exist 1 21 04 Sensor Information Updated K Fl Mnannerted Fa Ti T DS Rabti OF Al Bark ah Figure 45 Dialogue Box notification that calibration file does not exist Raw Data Measurement Protocols Calibration 5D Card PC Logging Warming and heating protocols are manually controlled in manual measurement mode Calibration Settings Current Calibration Serial Ma Slope Current Calibration Comment Intercept LU Be 1s 4 Load Defaults Measurement Options Figure 46 Default Calibration Loaded Warning 11 Any data processed with the default calibration will not be accurate This data can only be considered relative and may display improbable positive water potential values when measurements are made close to zero MPa PSY1 Stem Psychrometer Manual Ver 4 4 Page 81 of 162 16 5 Checking for calibration drift Calibration drift should be checked by overlaying the existing calibration file which is stored in the PSY1 against a 3 point check and plotting them against each other every time the chamber is cleaned This is achieved selecting the new calibration in the top drop down box and the previous calibration in the Plot Against drop down menu at the bottom of the window Then click Plot Natl Wet Chamber L arrected Molality Bulb Temp Wet Bulb Average 1 0 Mal Fi
146. range of standard sodium chloride NaCl solutions of known molality in the range 0 1 0 2 0 3 0 4 0 5 and 1 0 Molal The exact NaCl volumes per 50 ml volume of water are provided in the Appendix Preparation of Calibration Solutions These concentrations are derived from the work of Lang A R G Osmotic Coefficients and Water Potentials of Sodium Chloride Solutions from O to 40 C 1967 Australian Journal of Chemistry 20 2017 23 Appendix Osmotic Coefficients and Water Potentials of Sodium Chloride Solutions This range of concentrations correspond well to the typical range of water potentials experienced by crop plants and trees 0 642 0 915 1 368 1 823 2 281 and 4 640 MPa Saturated filter paper disks Watman s No 1 are used for calibration purposes These are supplied by ICT already cut to the correct 6 mm diameter size required for the calibration lid holder Replacements are conveniently obtained using a standard paper punch Measurement of thermocouple output in the suggested range is essentially linear at a given temperature Note 27 always use a freshly made NaCl calibration solutions using the recipe as per Appendix Preparation of Calibration Solutions It is recommended for those making calibration solutions for the first time to watch VIDEO 16 Making Calibration Solutions 16 1 Pre Calibration Cleaning The slope and intercept will be different for each psychrometer as the thermocouples are hand made using a very t
147. rnicmedsutemellt aeu esito bed ea reta i ors es a ten IM est on ue RUE Etat DE 20 6 3 Psychrometric measurement protocol isse rrr ite b eR TR ADU OEeE Te PUn rEME NS PPVE E eR RDUM YET O bats 22 6 4 Psvychrometric equatiolt desee tu m sei e abo edd Piste eU c NU E UI LU E NE EEUU EU E 23 6 4 1 Psychrometric Wet Bulb Depression ccccccsssccccsssececceececceesecesausececseeceesensecesauneess 23 6 4 2 chamber Temperature cerai o eo dcos et verita tdeo eec rv breed iunes 24 6 4 3 DIEN AVR e 24 6 5 Psvchtomettio error iinan etr eri Ev e d v ir eM obses lude vedi eendH RP dO bs 25 6 6 EgUMDr ATION TITIO accidet vedete eat vbt xdi aile euch N doi oett N 25 6 7 LASON CUS sets eco Mu oc toten atu utt ccu orbc act ut ur UM DE DUE 26 6 8 Temperature Gradient zinc v doen t vc d meni e da ud P uv de 26 6 9 Conden atom eiie a Gane tent ea tup a sone banat ondea Bde askoBag a nas l tron tied Ree Esu d oh 27 610 Osmotic POLGntidl unte sndecumvvdde odi Revvovite atrium ol tenes anda tih edd bi adluit pie add Aion etia Fanum 28 6 10 1 Collecting an Extracted Sap Sample on uve PUE aea reae akc eles 28 7 uharging Powernpg the instrament se ele thatch e uis pda tete ee eitutetes dts etant er ed aede 30 7 1 PSY T Current dra sacco ste iu te ou re deae petit alus i pe cubol us test abode taal opio spe ub Seu rs 31 7 2 Connecting a Power Supply to the Instrument eeeesseeeeeeeeeeeeen nennen 32 7 3 Connecting Power Directly via Solar Panel
148. s allowed to evaporate The Psychrometric Plateau representing the wet bulb depression is systematically determined by pausing for an empirically determined period 6 sec following the termination of the Peltier cooling Once all the condensed water has evaporated the temperature of the thermocouple returns to that of the bulk chamber represented by zero i e No difference between the thermocouple and bulk chamber Fig 3 PSY1 Stem Psychrometer Manual Ver 4 4 Page 23 of 162 Peltier Cooling Curve Peltier Cooling Curve Time since end of cooling S Figure 3 the Psychrometric Wet Bulb Depression is measured on the Psychrometric plateau at exactly 6 seconds after the end of Peltier cooling 6 4 2 Chamber Temperature Chamber temperature is important as this is the ambient temperature at which the psychrometric Wet Bulb Depression was measured It is used in the temperature correction of the raw psychrometric Wet Bulb depression as well as to determine the correction factor for AT based upon the conditions under which that measurement was made 6 4 3 Delta T AT Delta T is the difference in temperature between the air within the atmosphere of the chamber and the adjacent plant tissue The temperature of both the chamber air Thermocouple C and the plant tissue Thermocouple S are directly measured to determine AT In an isothermal state this value will be zero However in field measurements it is unreasonable to expect that this
149. s are under stress at values between 0 5 MPa to 2 5 MPa and greater for some arid plants At water potentials of this range a strong drying force exists and accuracy of a calibrated Stem Psychrometer is very reliable 6 6 Equilibration Time The stem psychrometer exhibits rapid vapour pressure equilibration However chamber temperature gradients as a result of handling the instrument or ambient fluctuations generally require more time to dissipate Calibration procedures require handling the instrument and usually 15 to 30 minutes are required to re establish thermal stability under controlled temperature conditions Following installation on a stem significant thermal gradients are usually apparent Furthermore disruption of local tissue water potential is likely to have occurred For these reasons some hours 2 to 4 should be allowed between the time of installation and the first reading Using the Live mode function you can watch in real time the thermal equilibrium occur as the AT and Thermocouple C values are displayed on screen These data can also be logged to a csv data file for post processing and analysis Provided adequate thermal insulation or temperature control of the installation has been employed subsequent equilibration to even rapid tissue water potential changes will be dependent only on vapour pressure equilibration The stem psychrometer exhibits favourable vapour pressure equilibration characteristics due to the
150. s charging 14 1 1 LED Flash Sequence Definitions 14 1 1 1 Green LED Usually indicates device is on not in a low power state 14 1 1 2 Red LED Usually indicates device battery is charging 14 1 1 3 Instrument Start up Green and Red LEDs blink alternately several times this is also to indicate a successful reset Green LED then turns on indicating that the board is powered on Red LED may turn on depending on whether the device is charging After a few seconds the Green LED should blink indicating that it has successfully initialised After a timeout depending on comms activity between the two boards both LEDs will turn off indicating that the unit has entered a low power state 14 1 1 4 Instrument Running Every 10 seconds the green LED will blink for a short amount of time This indicates the board has powered on and is looking for a RF signal generally a wake up signal If a signal is received it will stay on for a little longer to see if the messages are wake up messages or messages specifically for that unit If so the Green LED will stay on for another 30s 1minute 14 2 USB Communication LED s The second and smaller set of LED s are connected to the USB communications port They are located inside the communication port and are not visible if the communications port is closed The USB LEDs tell you activity on the COM s lines when a USB cable is connected or wireless comms via the MCC1 Radio Modem 14 2 1 Red LED
151. s prompted to accept or decline the new slope amp intercept The calibration process is covered in detail in the Calibration section of the manual ICT Stem Psychrometer Calibration Results Slope 4 06 Intercept 0 40 IF au wish to apply these settings now press OK IF you wish to review your calibration values or enter or change a comment press Cancel Cancel Figure 25 Confirmation Window before writing PSY1 Calibration settings to firmware 15 2 Measurement Options Measurement Options deal specifically with the duration of the Peltier Cooling Pulse and sampling point at which the Psychrometric Wet Bulb Depression is read after the end of cooling When a change is made to either parameter it is necessary to confirm this change and write it to firmware by clicking the Update icon If the change is not updated then no change is made to firmware and the next time the software is opened or the instrument connected the previous settings will remain Measurement Options Cooling Time waiting Time Update Figure 26 Drop down boxes to adjust the duration of the Peltier cooling time and sampling point 15 2 1 Cooling Time The length of the Peltier cooling pulse will determine the volume of water that is condensed onto Thermocouple C A short cooling time will result in a small volume of water that will quickly evaporate back into the atmosphere of the chamber Conversely a long cooling time will condense a large volume o
152. sed to stimulate kino formation Tippett 1986 Although all Eucalyptus species produce kino i e for the 93 species which have been evaluated species vary in vein location and sensitivity to venation Most species form kino veins in xylem 17 9 2 1 Cleaning a Forstner Bit Hole The hole bored into the xylem of the stem must still be rinsed with distilled water several times to ensure the living tissues of the spilt cells caused by the boring process are washed clean of the prepared site Again lint free tissues such as Kim Wipes must be used to vigorously dry the xylem surface at the bottom of the bored hole as well as the water introduced into the hole that will have been absorbed by the surrounding bark especially at the bottom arc of the hole where the water runs to after washing Failure to sufficiently dry this water will result in an extended delay to reach vapour pressure equilibrium between the psychrometer and the sap wood or in the worst case compromise the installation through condensation that would prevent any measurements being made PSY1 Stem Psychrometer Manual Ver 4 4 Page 109 of 162 17 9 2 2 Forstner Bit Hole Attachment As mentioned a 26 mm diameter Forstner bit leaves a 0 5 mm gap around the perimeter of the psychrometer chamber This tolerance allows easy insertion of the chamber into the hole which in many species can be up to 25 mm deep or the full depth of the psychrometer chamber itself It also affords the a
153. silicon grease at installation will minimise the risk of contaminating the inner chamber with grease during de installation This is sometimes a hazard when removing an instrument and the danger can be reduced by wiping away excess grease before removing the psychrometer and by lifting the psychrometer straight off the site of attachment rather than allowing it to slide A Video 24 dedicated to the de installation of the psychrometer should be watched prior to installing or de installing the psychrometer for the first time It is also recommended that a second Video 25 demonstrating the preparation of the psychrometer for re installation in the field be watched before attempting installation for the first time This video demonstrates the added issues associated with field work and important tips for successful installation of the stem psychrometer in the field WARNING 14 if the psychrometers have been permanently uninstalled at the end of the season or a research project do not pack them up without first cleaning them Please refer to the sections on Cleaning and Storing the psychrometers PSY1 Stem Psychrometer Manual Ver 4 4 Page 104 of 162 17 9 Installation on Large Diameter Stems As previously described the preferred installation technique is to attach the psychrometer to a small lateral branch of the plant or tree adjacent to the main stem or trunk In most case this is easily achieved However in large diameter mature trees lateral
154. strument and confound accurate calibration procedures The relatively stable temperature of a large room is preferable Corrections for ambient conditions can be made using the formula above 16 3 Calibration Chamber Here is a simple and effective means to achieve stable temperature control You will require a good quality circulating water bath preferably with proportional control of water temperature This eliminates the typical sawtooth temperature control of less sophisticated baths Circulate the water through a flexible copper tube 1 2 cm diameter and 2 3 m long which is then coiled and placed inside a box close to the inside edges Construct the box of dense styrofoam eg 5 cm thickness Styrofoam SM and line all inside surfaces with a reflective foil eg aluminium foil The dimensions of the box should accommodate the number of psychrometers you intend to calibrate as well as one or two small electric fans to facilitate air mixing Internal dimensions of approximately 50x50x50 cm are appropriate Suspend a light plastic grid in the centre of the box to serve as a platform for the psychrometers This allows air movement around the instruments and eliminates temperature gradients from conductive surfaces Normal equilibration times for salt solutions are quite brief but it is safest to allow between 30 to 60 minutes for each solution to equilibrate depending upon how intensively the psychrometer was handled while loading the calibration s
155. sure a long term vapour seal on a Forstner bit installation First is as described in the preceding section silicon grease can be applied directly on the face of the chamber Alternatively to limit the potential for silicon grease to compromise the xylem surface or thermocouples a bead of silicon vacuum grease can be run around the perimeter of the psychrometer chamber at the interface between the stem and the psychrometer sealing the 0 5 mm void Again this is not designed to provide the vapour seal This has already been achieved with the interface of the psychrometer face and the flat bottom hole bored into the xylem of the stem It is designed to act as a barrier to foreign bodies entering between the hole and the chamber and to insure that the vapour seal is not momentarily lost through the swaying action of the tree 17 9 2 4 Insulating a Forstner Bit Installation The insulation around the chamber from being surrounded by bark is useful but not sufficient to fully dampen and insulate the psychrometer form ambient thermal gradient The whole installation and stem should still be wrapped in foam and covered with Aluminium foil to reflect direct radiation and prevent it from heating the whole installation a n T AT GA xa SAN lt X P a l a i a og T AS ya ga AN a 7 s gt 7 s un s een Sa ee 2 AX Y 1 e Id z Sota NC im or OA E E 4 aq Photo 40 foam and aluminium foil insulating
156. surement Stopped MEAS Next 00 00 False MPROT CalSN PSYTC705 MPROT CalCmnt Slope 1 16 Intercept 1 28 MPROT CT 10s MPROT WT 6s MPROT PWD Disabled MPORT PWW 15s MPROT CHD Disabled MPROT CHS 1 01 2000 12 00 00 AM 1 01 2000 12 00 00 AM True Logging Options DT WB Chamber Temp Correction Factors Battery Voltage External Supply Presence OS Microsoft Windows NT 6 1 7601 Service Pack 1 Runtime 2 0 50727 5456 Processor Count 4 PSY Support Log Complete 30 07 2012 3 26 21 PM PSY1 Stem Psychrometer Manual Ver 4 4 Page 159 of 162 22 10 Debug File Computer Information ACPI DevicelD ACPI GENUINEINTEL_ _X86_FAMILY_6 MODEL_28 _0 Name Intel R Atom TM CPU N270 9 1 60GHz DevicelD ACPNAGENUINEINTEL X86 FAMILY 6 MODEL 28NV 1 Name Intel R Atom TM CPU N270 9 1 60GHz DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD DevicelD ACPI PNPOCOC 2 amp DABA3FF amp 0 Name ACPI Power Button ACPI PNPOCOD 2 amp DABA3FF amp 0 Name ACPI Lid ACPI PNPOCOE 2 amp DABA3FF amp 0 Name ACPI Sleep Button ACPI PNPOCOA O Name Microsoft ACPI Compliant Control Method Battery ACPI ACPI0003 2 amp DABA3FF amp 0 Name Microsoft AC Adapter ACPI PNPOA08 2 amp DABA3FF amp 0 Name PCI bus ACPMPNPOCO244 amp 38462492 amp 0 Name Motherboard resources ACPNPNPO200M amp 38462492 amp 0 Name Direct memory
157. switch for approx 1 second You will see the Green LED turn on The LED will remain Green for approx 10 to 15 seconds before turning off The LED will then Flash Green once every 10 seconds to confirm that the unit is powered on PSY1 Stem Psychrometer Manual Ver 4 4 Page 53 of 162 Power Switch Small Black Button Located above USB Port 1 ae ee i TE Photo 18 PSY1 Power Switch NOTE 17 The PSY1 can also be automatically powered up by connecting it to a 12V DC power supply This can either be in the form of a 12V DC mains power plug pack a solar panel solar panel amp 12V battery direct to the instrument or through a shared power distribution system in which a large solar panel and battery provide power through a distributed wired network to any or all instruments connected see Charging Powering the Instrument 12 2 Turning the PSY1 OFF The PSY1 DOES NOT turn off automatically If external power is disconnected from the instrument it will continue to operate from and discharge the internal battery It MUST be turned OFF manually This can be done by using the power switch To turn the device off press and hold the power switch for approx 3 seconds The LED will alternately flash Red then Green for a few seconds before stopping and all lights are extinguished The PSY1 can also be turned off via the GUI software From the File menu select Power Off PSY1 The LED will alternately flash Red then Green for a few s
158. t Chamber heating duration Disabled v 29 51 Calibration File Written OK 29 51 Please Wait i v 29 51 Calibration History Saved OK Chamber heating between and v Always allowed 4 Update Chamber Heating Connected to ICT PSY Batt 4 02 V Port COM61 Device Date 02 05 2012 Device Time 24hr 21 58 Figure 23 The Measurement Protocols are situated on a dedicated tab in the software 15 1 Calibration Settings This is an instant reference of the calibration slope and intercept that will be applied to the raw Psychrometric Wet Bulb Depression to convert it to Water Potential in MPa The actual calibration file is stored on the MicroSD card using the four digit serial number of the psychrometer chamber that was calibrated Calibration Settings Current Calibration Serial Ma Slope Current Calibration Comment Intercept r Load Defaults Figure 24 Summary listing of the calibration settings applied to the PSY1 PSY1 Stem Psychrometer Manual Ver 4 4 Page 66 of 162 The calibration file contains the serial number of the PSY1 that was used to perform the calibration along with a user comment to reference the time or reason the calibration was performed This information is read from the cal file and displayed in this window After calibration of a psychrometer the new calibration slope and intercept will automatically be updated in this field Before it is written to firmware the user i
159. t Connected to ICT PSY b Battery Voltage NOTE 20 the Battery Voltage of the internal battery of the PSY1 will be displayed upon initiation of the connection The integrated voltmeter measures the internal battery voltage as soon as a connection is initiated and displays it in the status bar This provides a diagnostic check during the connection process and prevents frustration that would otherwise occur should the instrument not be able to connect due to a flat battery c Please Select Device NOTE 21 The PSY1 is a Plug amp Play USB device Once connected to a USB port Windows automatically detects it and allocates it a COM port You do not need to select or configure the COM port Once connected the allocated COM port will be displayed here 13 1 3 Connect to PSY To establish a connection click Connect to PSY There are two ways of connecting to the PSY1 either via direct USB connection or via wireless RF Modem PSY1 Stem Psychrometer Manual Ver 4 4 Page 55 of 162 13 2 USB Connection m Device Selection 13 2 1 USB Connection Type Available Devices Drop down the Connection Type box M located in the bottom left hand corner of the screen and select USB No compatible devices found If the message No compatible devices found is displayed before proceeding to click the Find Devices icon please check C Show All Ports Remember Devices the followin onnection T ype e e a T F Figure 9 Device
160. t field campaign NOTE 13 Dow Corning high vacuum grease 150 gram tubes is inert heat stable silicone grease and is recommended for use in sealing the psychrometer chamber and calibration lid Products such as petroleum jelly or Vaseline cannot be used as it melts at a very low temperature and leaks into the chamber Application of several 2 3 small drops on the lid is all that is necessary to seal the calibration lid to the chamber Apply 2 3 drops and then once the calibration lid is attached to the psychrometer twist the two surfaces to spread the vacuum grease and form a seal VIDEO 15 Watch how to apply the sealant to the calibration lid PSY1 Stem Psychrometer Manual Ver 4 4 Page 50 of 162 11 Software amp USB Driver Installation 11 1 Instrument Set up and Configuration NOTE All changes that you make and confirm by clicking the relevant Update icon will be stored in non volatile memory That is they will be retained even if you turn the power off and on 11 2 PSY1 Utility Software NOTE All software described in the proceeding section are included on the ICT Installation DVD and on the MicroSD card installed in the instrument 11 2 1 Installation A Graphical User Interface GUI is used to configure and operate the PSY1 Stem Psychrometer The GUI or Utility Software operates on Microsoft Windows Operating Systems OS and is compatible with Windows XP Windows Vista and Windows 7 a Install the USB driver ict us
161. t is not installed or an older version of DotNet is installed on your PC In either case you will need to install DotNet3 5 before proceeding and completing the installation of the ICT utility software This is a free software download from the Microsoft web site ICT has provided the direct Hyperlink for your convenience http download microsoft com download 6 0 f 60fc5854 3cb8 4892 b6db bd4f42510f28 dotnetfx35 exe Alternatively if this link does not work try the following http www microsoft com downloads en details aspx FamilyID 333325fd ae52 4e35 b531 508d977d32a6 Scroll to the bottom of the page and click on the following link Full Redistributable Package To download the full redistributable package rather than the bootstrapper click on the link below to start the download NET Framework 3 5 full package Top of page Related Resources a NET Framework 3 5 readme NET Framework 2 0 Service Pack 1 KB Article NET Framework 3 0 Service Pack 1 KB Article Top of page NOTE 14 the full redistributable download file 300MB has been provided for you on the ICT Software DVD that came with your instrument and can also be found on the Micro SD card installed in your Instrument These links are provided as a convenience should you not be able to find the dotNet install file in either of these locations DotNet Framework is a minimum requirement Only install if required to The listed links are to an external site and m
162. ta file follows the same format as a psychrometer data file It includes a Header line that records all of the instruments settings Columns headings row separate Date and Time Columns and the measured outputs from the psychrometer chamber av O a a a a A a as2s5 uL ELE LL ELE I je a a a a a a Internal COM Ver R1 3 0G Instrument Name ICT Demo Stem Psychrometer Comment Armidale NSW Australia Chamber Date Time Temperature fe uV tion Voltage Supply Present v 5 11 2010 0 17 22 37 not present 5 11 2010 0 17 22 37 not present 5 11 2010 0 16 22 36 not present Cold CJ CD Correc Battery External Power dT uV Thermocouple Junction oy Es Factor 5 11 2010 0 13 22 37 8 29 not present 5 11 2010 0 14 22 37 8 29 not present 5 11 2010 0 16 22 37 8 29 not present 5 11 2010 0 16 EN 22 36 8 29 not present 5 11 2010 0 15 22 3 8 29 not present o lon lon 5 11 2010 19 05 48 22 36 0 15 23 92 22 36 8 29 not present 5 11 2010 19 05 49 22 36 0 11 23 92 22 36 8 29 not present 5 11 2010 19 05 50 22 37 0 11 23 92 22 37 8 29 not present Table 1 Example of a Live Data Data File N PSY1 Stem Psychrometer Manual Ver 4 4 Page 128 of 162 19 3 Delayed Start The delayed start function allows the user to configure the instrument in advance of use In many situations it may be preferable to set all instruments to the same predetermined start time prior to deployment in
163. ter Manual Ver 4 4 Page 59 of 162 13 3 4 RF Device Chooser Clicking on the Select Device icon will open the RF Device Chooser List RF Device Chooser E see Address Serial Num Device Name Discover Connect Cancel Figure 16 RF Device Chooser Window The list will initially be blank until a search has been performed for instruments within range approx 250m NOTE 23 Range is strictly line of sight and will vary depending up ambient conditions that affect signal strength such as atmospheric moisture and density of foliage 13 3 5 RF Discover Click on the Discover icon to begin the Device Wake Up Routine RF Device Chooser v Save Delete Address Serial Num Device Name Please Wait Device Wake Up Routine In Progress Cancel Figure 17 RF Device Chooser Window attempting to wake up devices within range PSY1 Stem Psychrometer Manual Ver 4 4 Page 60 of 162 Each PSY1 instrument has an integrated radio transceiver and antenna They are configured to wake up every 10 seconds for a millisecond to send a short signal 13 3 6 RF Device Wake Up Routine During the Device Wake Up Routine the RF Modem scans the 2 4 GHz frequency for a period of 20 seconds listening for a signal from any PSY1 Stem Psychrometers that may be within range As each unit only emits a signal every 10 seconds an initial wait time of 20 seconds is required to ensure
164. the corresponding psychrometer chamber form the above installation Note the callus residue in the chamber and the broken Thermocouple S on the right hand side PSY1 Stem Psychrometer Manual Ver 4 4 Page 98 of 162 17 3 3 Sample Preparation on Herbaceous Stems On non woody or herbaceous stems site preparation is even more critical Exposing the chamber to discrete xylem is often impossible and would involve considerable wounding Wounded herbaceous tissue tends to respond with callus formation more quickly than woody stems and this severely limits the period of reliable measurements Often abrasion or scraping of the cuticle to expose the cell layers adjacent to xylem conduits followed by thorough rinsing and wiping will result in reliable measurements for at least a week following attachment This will vary considerably with species and preparation success Correlating measurements with a pressure bomb may be required to establish a successful technique for some species Photo 30 use a razor blade to expose the water conducting tissues VIDEO 22 the complete process of preparing the stem and attachment of the psychrometer is demonstrated in the Installation Video It is recommended that this video be watched prior to attempting an installation for the first time PSY1 Stem Psychrometer Manual Ver 4 4 Page 99 of 162 17 4 Positioning Thermocouple S Prepare the stem psychrometer for attachment by removing the calibration disk holde
165. the plateau to measure the Psychrometric Wet Bulb Depression Time since end of cooling S Figure 29 Peltier Cooling Curve produced with a 5 second cooling time the plateau extends to 10 seconds before returning to zero reference PSY1 Stem Psychrometer Manual Ver 4 4 Page 69 of 162 Now wait a few minutes preferably 10 minutes to allow the vapour pressure to return to equilibrium within the chamber and repeat the measurement but this time increase the cooling time from 5 seconds to 10 seconds There will be negligible if any difference in the measured uV output of the Psychrometric Wet Bulb Depression but the Peltier cooling curve will be approximately twice as long as the previous measurement extending to approximately 20 seconds before sharply dropping and returning to zero reference This clearly demonstrates the Psychrometric principle that the Wet Bulb Depression is the temperature at which water condensed on the Thermocouple C cools the thermocouple as it evaporates It also shows the independence of the measurement to the volume of water condensed on the Thermocouple yet the significance this can have on the temporal logging interval If measuring well hydrated plants in the wet end of the plant water potential range close to zero it may not be possible to measure at 10 minute logging intervals instead 15 to 30 minute intervals may yield better results Peltier Cooling Curve Peltier Cooling Curve 6 Secon
166. thermocouple of a classical Psychrometric measurement of vapour pressure Upon initiating a measurement Thermocouple C is momentarily measured This is a measure of the electronic noise or offset from electronic zero of the instrument which we call the Electronic Dry Bulb Offset EDBO The PSY1 uses this value as the zero set for the measurement and is automatically performed before each measurement either in the manual mode or when configured for automatic logging Note 51 In the Live mode the Chamber Temp is continuously monitored and updated 18 2 4 Measurement Status This is a user feedback feature that details each stage of the measurement process 18 2 4 1 Initialising ADC Powering up and stabilising the microprocessor 18 2 4 2 Initialising Measurement Equilibrating the electronic circuit PSY1 Stem Psychrometer Manual Ver 4 4 Page 119 of 162 18 2 4 3 Peltier Cooling Generating and passing a Peltier cooling pulse through Thermocouple C to cool the thermocouple and condense water within the chamber from the gaseous phase to liquid phase resulting in a Psychrometric Wet Bulb Depression 18 2 4 4 Measurement in Progress Waiting for a user definable time typically 6 seconds before reading the uV output of Thermocouple C this is the Wet Bulb Depression The measurement then continues to monitor the thermal decay as Thermocouple C returns to zero This is done as a verification of performance and accuracy of the measurement Not
167. this error by direct measurement Gentle nudging of the sample thermocouple Thermocouple S into position is often necessary to ensure that it is extended sufficiently to make contact with the sample surface This should be done with the aid of a hand lens or dissection microscope and fine forceps See Handling the Instrument The integrated microprocessor measures the temperature gradient within the chamber between Thermocouple C chamber air and Thermocouple S sample temperature A positive gradient indicates that the sample is cooler than the chamber air In this case the absolute value of the calculated error is subtracted from the absolute value of the measured water potential In other words the sample is at a higher less negative water potential than the value determined by the C thermocouple in the chamber air which is at a slightly warmer temperature Calculation of the correction in water potential measurement is automatically calculated by converting the measured voltage to temperature The calibration coefficient for chromel constantan thermocouples is 61uV C Having assessed the temperature gradient which causes the error in measured water potential the correction factor which is itself a temperature dependent variable is applied This factor is 8 20 MPa C at 25 C and increases to 8 38 MPa C at 20 C The temperature dependence of this factor is dynamically recorded and applied to all readings making the measurements dir
168. tion function and instructions are included However ICT does offer a calibration service for an additional fee Please contact ICT for more information and a formal quotation 5 3 Clamping A clamping device is required to attach the psychrometer to a plant stem Two sizes of clamps are available a Small Clamp PSY SC for stem sizes up to 25 mm diameter and b Large Clamp PSY LC for stem sizes between 25 to 50 mm in diameter Use of the stem psychrometer with larger stem sizes will require a customised clamping mechanism and these are explained in section 17 Installation under sub section 17 2 Large Diameter Stems However these two basic clamp sizes should be adequate for most applications This is because the stem water potential is an absolute measure of the integrated water potential within the plant at the point of measurement Whilst gradients will exist vertically in the plant stem water potential measured on a lateral branch adjacent to the stem which may be small enough to attach a psychrometer using one of the two standard clamp sizes will be directly representative of the stem water potential of the adjacent main stem or trunk of the plant 5 4 Measurement Options The PSY1 Stem Psychrometer can then be used as a psychrometer for 1 In situ water potential on the stem 2 In situ water potential on the leaf 3 Water potential on excised stem tissue 4 Water potential on excised leaf tissue 5 Or as an osm
169. tput is lower than expected approx only 13 uV at 6 seconds after the end of cooling and instead of the cooling curve dropping sharply to zero as the thermocouple warms quickly due to the condensed water evaporating it has a slow drift back towards zero In fact even 30 seconds after the completion of the measurement all of the condensed water has yet to fully evaporate trapped by the organic contamination of the thermocouple resulting in the failure of the thermocouple to warm back to zero or the starting reference temperature zero uV Peltier Cooling Curve 20 15 10 gt 2 5 LED 5 0 10 20 30 40 Time since end of cooling s Figure 6 the characteristic response of a dirty Thermocouple C that requires cleaning Photo 15 the corresponding psychrometer that generated the Peltier cooling curve in Figure6 Note there is no visually obvious dirt or contamination This is why it is important to clean and test with a 1 0 Molal NaCl solution before deployment PSY1 Stem Psychrometer Manual Ver 4 4 Page 47 of 162 Figure 7 shows the results after the chamber was cleaned The results are now as expected a Wet Bulb Depression in the range of approx 19 uV producing a Water Potential of 4 64 MPa for a 1 0 molal solution The thermocouple had been dirtied by a small amount of organic material and mild oxidation of the thermocouples This disrupted the process of condensation and evaporation of water on the thermocouple Once the contam
170. tput of the Thermocouple C is recorded at a sampling frequency of 10 Hz or 10 times per second A Psychrometric Wet Bulb depression is read at six 6 seconds after the end of cooling and automatically corrected for any measured temperature gradient between the Thermocouple C and Thermocouple S Finally these data are automatically processed using the Stem Psychrometer equation applying the chamber specific calibration to yield the precise measurement of the sample s water potential A copper constantan thermocouple is embedded in the chamber body to allow measurement of chamber temperature This temperature value is recorded by the PSY1 and used to automatically correct the reading to 25 C an arbitrary standard reference for water potential measurements The stem psychrometer provides the means to measure in situ water potential over a wide range 0 01 Mpa to 10 Mpa with accuracy and repeatability However certain precautions as detailed in the following sections must be adhered to if meaningful results are to be achieved Video 10 presented by Prof Mike Dixon is a concise explanation of the Stem Psychrometer Theory Including the theoretical principle employed by the PSY1 Stem Psychrometer to measure stem water potential the chamber design nomenclature used to describe the internal components of the chamber and the measurement procedure Stem NL m Vacuum Grease t io Figu re 2 Psv1 stem Psychrometer principle schematic P
171. trument Set up and ConfIguratloD snae es bo dee a eur e atu b Soda 51 Lc DpSYIOUNUDZSOPRWAEG 04 meidotsMeesinridn uoles ie i ops Look sheund obti iota ie Qi QUL qe cube codo T 51 iu MEME cuori 51 12 TUM THE Strument ON recria P O YO 53 TUE mte cae ce Doo dais tan edv Meta er mre ene O rere Best upto eee eee 53 12 2 TOV Ue POY TOR etatem iosetac tageeienatns cca N 54 13 Communications Connect to the Instrument sseesseeseeeseeeeeeeenn nennen eene nnne nnns 55 13 1 1 The opening Splash Screen displays the following c ccsesecccessececeeseceeeeeeceeseeeeeeees 55 13 1 2 A status bar along the bottom of the WINKOW ccccccsecccseceessecseeeeeseeeceseeeseeeneeeeens 55 13 1 3 ConnectTo PSY oie mE oon itus um ene cei eee aep IUE EUN 55 135 2 USB COMECON aren i elected coded deed en Sud E iuo duse Ud i o E 56 13 2 1 USB CONNECTION DVDS uenia dr M Reve nice neret a Nes i do ONE o xe dva ets 56 13 227 JMISB Eind DeVICBS sao antttedetsctnebetus a E de a RdE 56 13 23 USB Select DeVICB a s ERU tI FOE db eta EE Dd WEE BRA Eu CFI DOE Rd T 57 13 3 MCGCISRPMOGOGIS isnie ua lene Era hun Bote pho Pagar Cato Man UE Dua a ba Beatae aS aa 59 1334 RPConbecdoH PV DE sis eestesteide neos e vert bp Feslas oiv dde 1o Pede Ee dve del Gb dosbust vd eod a a3 OE VE edet 59 1332 M M Ie DEVICES Roe CS 59 15 3 9 IRE SCICCE DEVICE iste edet boue a ic ete ibetee M aestnfbatet is ev educta
172. ue ae e a iA se intl cnt Seek Apu E Pete SUC as hte Sal oat BUE 67 X MEE CNET TL 71 15 3 Reverse Pemer Warmin eana eran se hone atul d sus e b cam oU Rua ti cR DL Mr M IAE I SU MeU 71 154 Chamber Heating 5 d nea tto ho No d eto e ch pcs Daun bo Pom oss 71 16 al Fe GI pasos nese egos aes ten wc Seow natal vet ee ness oe oa decease cbr tests eee o UH 74 16 3Prescalibratiod lea iecore ivn iur aed une to seen EMeUE un T Cet taU ene Pere vaasteie eg andecuanamadesenaseenarenedes 74 16 2 Calibration Temperabtul e oe e a co aee cd serat e rod P oU Eat ob D vivO dene oen M o sue EG 75 16 3 alubradHon Chamber uiis vs iuda i tuta NE eub cci dr ueesult deat ener dat naeis 75 16 4 C hprauon PrOLOCD esee ce nrbe tz PR RO esed ev mA cU doce d deos dena 76 iom Start CaliDratl On Hcc 76 16 4 2 Loading the Calibration Filter Paper cecene e 77 16 4 3 Selecting the Calibration Range cccccsssccccssseccccesececcesecceeeeseceseeececeeeceesegeceeseeeeeeeas 77 1644 Start Vleasut eie DES oce dieto aonn ide Retell dats stamet A i Pe dade bu ub Dita ii Das 78 16 4 5 Generate Calibration CUVE iii rite px tr c exea TEE AGANT Ma ETE VC RURERES A VEA OG ETIN aAA 78 16 4 6 Write Calibration to Firmware eeeeseessseseeee eene eene nnne nennen nnne nnns 79 16547 Calibration storage OCatl OM uenerit Ebro ee Ho ERE REESE rei beoe eae 80 16 4 5 Loading a Different Calibration ciis iot ud ud ito C RARE a SERRE od dente UOS CUP Ra cbe TES 80 16 4
173. upon which to always make the Psychrometric Wet Bulb Depression measurement 15 3 Reverse Peltier Warming The reverse Peltier Current or warming is used to dry off any microscopic beads of water that may remain on the thermocouple following a measurement You can automate this to provide a user defined temporal interval for warming of Thermocouple C prior to taking a measurement There is also a user adjustable wait time which prevents a measurement from being taken to allow the thermal gradients small though they are to dissipate from the chamber before the next measurement Reverse Peltier warming Thermocouple warming is performed before a measurement takes place to ensure a dry measuring junction Disabled v Wait before measurement Disabled 1s Figure 31 Reverse Peltier Warming settings Warming duration 15 4 Chamber Heating Under environmental conditions that favour undesirable temperature gradients i e the chamber is colder than the stem the heater can be used to mitigate these problems A 12 V DC resistive heater is integrated into the back of the chamber and controlled by the PSY1 The chamber heater can be set to automatically turn on immediately following the completion of a measurement The duration of the chamber heating can be set by selecting the desired time period from the drop down box The exact duration for every installation will be specific to the ambient conditions and the plant bei
174. urve Peltier cooling curve can be plotted for the last measurement taken by the Stem Pasychrometer ooo 3 Get Latest Data Plot Figure 88 Peltier Cooling Curve Get Latest Data icon 20 1 2 Plot Click this icon to automatically plot the Peltier cooling data Plot Peltier Cooling Curve Peltier cooling curve can be plotted For the last measurement taken by the Stem Psychrometer Y net Latest Data Figure 89 automatically plot the latest Peltier Cooling Curve data by clicking the Plot icon PSY1 Stem Psychrometer Manual Ver 4 4 Page 135 of 162 20 2 Peltier Cooling Curve Plot The graph generated displays time in seconds s along the X axis and Thermocouple C output uV on the Y axis Time zero the end of the Peltier cooling pulse The plot begins at Time 4 5 s after the end of the Peltier cooling pulse This provides a 1 5 second section of plot prior to recording the Psychrometric Wet Bulb Depression at 6 seconds the standard wait time protocol after the end of Peltier cooling The plot of the Wet Bulb Depression plateau commences at 4 5 seconds after the end of cooling The duration of the plateau will depend on two main factors 1 water status of the sample a wetter sample less negative water potential closer to zero MPa will take longer to evaporate and 2 the cooling time a longer cooling time say 10 seconds will condense more water on the thermocouple than will a short cooling t
175. value will actually be zero and even small differences in temperature between the two can have a significant effect PSY1 Stem Psychrometer Manual Ver 4 4 Page 24 of 162 6 5 Psychrometric error Accuracy of the stem psychrometer at the wet end of the spectrum around zero OMPa is a limitation of the physics of the Psychrometric principle Where there is little to no drying force it is difficult to convert liquid water back into vapour phase and condensation within the chamber is always imminent Around zero OMPa the error is significantly greater than at water potentials of 0 5 MPa or lower As soon as there is a drying force acting upon the thermocouples within the chamber to drive evaporation the error dissipates rapidly and the accuracy improves Small positives of 40 1 to 40 2 MPa whilst not theoretically possible to be measured using psychrometry are not of serious concern especially when you see good diurnal rhythms and can be ignored as mathematical artefacts A positive offset is also not applicable across the whole data set because the error is dissipated very quickly once a drying force is generated as you extend beyond the very wet water potential range NOTE 5 In the majority of applications the wet end of the water potential spectrum below 0 5 MPa is of only moderate interest as most plants do not exhibit water stress at these levels The majority of water potential and water relations research is conducted when plant
176. ween these measured values This facility provides a convenient evaluation tool of the psychrometer chamber during setup to ensure optimal performance prior to deployment It is also a good diagnostics tool for trouble shooting a faulty psychrometer chamber and can even be used as a positive feedback tool during lab based manual measurements It is not designed to replace statistical analysis of data which should be performed on logged data downloaded from the instrument These statistics are not controlled and will be applied to any values recorded by the PSY This means the statistics calculated could be from multiple psychrometer chambers attached to or interchanged with the PSY1 through the course of testing therefore rendering the results invalid To reset the statistics click the r icon to the right of the Difference field Statistics Statistics shown below are calculated based on measurement results captured by the ICT PSY utility software These statistics are not stored on the PSY sensor interface Min Difference Max Av T Figure 72 Statistics on manually performed measurements PSY1 Stem Psychrometer Manual Ver 4 4 Page 122 of 162 19 Measurement Control 19 1 Measurement Mode The drop down box provides a menu of the possible temporal logging intervals with which to operate the instrument 19 1 1 Manual This mode allows the user complete control over the initiation of a measurement A measurement can only
177. ychrometer will be completely covered by the sample Remove the bark phloem and cambium layers and use a single edged razor blade to scrape a flat area of xylem upon which to mount the psychrometer Note 38 Use relatively short straight passes with the razor blade in a forwards and backwards motion Be very careful to maintain a level plane rather than a scooping action that will cause a concave surface It is not possible to achieve a vapour seal with a psychrometer on a concave or convex surface Photo 22 use a single sided razor blade to expose the xylem and scrape a flat surface PSY1 Stem Psychrometer Manual Ver 4 4 Page 93 of 162 It is very important to achieve a flat surface when exposing the xylem The calibration lid can be used as a surrogate for the psychrometer chamber to visually check the flatness of the prepared site Ensure that no small gaps exist between the calibration lid and xylem surface by looking for flecks of light between the two surfaces If no light can be seen then proceed to cleaning the prepared site PM Photo 23 use the calibration lid to check for a flat surface of the exposed xylem Thoroughly clean the area with distilled water and wipe dry This will remove spilled cell contents It is important to the success of the installation that all living tissue is removed and no free water is left on the xylem surface Often some degree of xylem wounding is unavoidable In species incorporating r

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