Delta-T Soil&Plant 12page
Contents
1. IMAG Cultil ne Tel 31 10 5294294 Fax 31 10 5294299 Website www cultilene nl Sponsors of research into horticultural media applications and suppliers of horticultural media calibrations Exclusive suppliers of mineral wool media calibrations to customers in the Netherlands Applied Plant Research Division Glasshouse Horticulture Praktijkonderzoek Plant amp Omgeving B V former Research Station for Floriculture amp Glasshouse Vegetables P O Box 8 2670 AA Naaldwijk The Netherlands Tel 31 174 636700 Fax 31 174 636835 Website www ppo dlo nl Developers of the WET calibrations for horticultural media 2001 ATi ith SAINT GOBAIN ne APPLIED PLANT RESEARCH Ordering Information WET Sensor Kit type WET 2 K1 Comprises WET 2 d WET Sensor HH2 Moisture Meter spare battery user manuals and carrying case Supplied with sensor calibrations suitable for a variety of standard soil types WET Sensor Kit type WET 2 K4 As WET 2 K1 plus WET GH 1 substrate calibrations upgrade WET Sensor type WET 2 d Combined water content electrical conductivity and temperature probe Includes sensor calibration on 3 5 disk 2m cable with 25 way D connector For use with HH2 only Moisture Meter type HH2 See page 4 for Moisture Meter ordering information NB the HH2 can only be configured for use with a single WET Sensor Swapping between different WET Sensors requires the use of a PC and takes a fe2. for hand held use Long cable runs possible Easy to include in large scale logging set ups Performs well in most soil types including clays Usable in saline soils up to 2000 mS m 1 accuracy Precision measurements at moderate cost Holds soil closer to central rod when drying and cracking 2 and 3 rod sensors and particularly flat pcb devices don t do this Measurements can be made close to the soil surface Withstand repeated insertion in soil Can be replaced at low cost if bent or damaged Highly resistant to corrosion Narrow rods with sharp tips minimise errors due to soil compaction as rods are inserted Easy to insert and remove in augered holes Rapid attachment of extension tubes Handy size for portable use Rugged waterproof and buriable to 5m World wide availability Reassurance of quality Advice on complete systems Comparison with other techniques TDR ThetaProbes have some clear advantages over TDR systems In general terms ThetaProbes are more stable less troubled by salinity easier to log use less power have simpler cabling requirements and can be used to make spot readings on the move as well as buried for long term logging Neutron Probes have many drawbacks when compared with ThetaProbes they create licensing and safety problems they cannot measure the top 25cm of soil they cannot be data logged and the overall cost of ownership is high Profile Probes are in many re
3. which is the EC of the water that is available to the plant Readout and data storage Readout and data storage are handled by the HH2 Moisture Meter The HH2 is able to display the 3 outputs produced by the WET Sensor and store them until downloaded to a PC Standard calibrations for Mineral Organic Clay or Sand media can be selected In addition user defined custom Probe Output e Bulk conductivity ECD e Temperature C e Permittivity 1 Calculated parameters e Volumetric Soil Moisture 6 e Pore water conductivity ECp Notes Accuracy Resolution Units 80 0 03 2 0 001 Depends on water content and conductivity see graph 1 Permittivity is a measure of the dielectric properties of materials soil 7 1 0 calibrations can be entered for soils and other substrates User selectable options allow pore water and or bulk conductivity to be displayed and also the pemittivity The HH2 provides user selectable temperature compensation Horticultural Media Calibrations The WET sensor is particularly valuable in greenhouse or protected environment applications for fertigation monitoring Special WET GH 1 substrate calibrations can be ordered as a set for a variety of horticultural media including coir peat based potting mixes and greenhouse mineral soils WET Sensor Specifications Frequency Response time imensions amp weight Probe housing 55 x 45 x 10mm Rods 68mm long
4. Coffee grape vine kiwi fruit ligustrum mesquite potato rose hibiscus Almond apple avocado cypress fir eucalyptus ficus kumquat mangosteen oak orange pecan pine poplar red cedar tangerine Sap Flow systems building Dynagages and TDP sensors can be used with the Delta T DL2e Data Logger It records raw data which can be converted to sap flow subsequently using spreadsheets Systems comprise e The necessary sap flow sensors and extension cables e D AVRD Voltage Regulator s e Any other meteorological or soil sensors required typically soil moisture soil temperature rain etc e The DL2e and communications system e Mast or pole mounted enclosures e Batteries solar power modules or mains power systems Ordering Information Please contact Delta T or your local Delta T distributor to discuss your TDP and Dynagage requirements A quotation for a Suitable system will then be issued In use sap flow systems require a continuous power supply For remote sites Delta T can provide customised solar power charging systems Dynagage 5mm Microsensor type D SGA5 References ref 1 Granier Andr 1985 Une nouvelle m thode pour la mesure du flux de s ve brute dans le tronc des arbres Ann Sci For 1985 42 2 193 200 TDP Probes are licenced under patents by INRA All rights reserved Porometer type AP4 Direct readout of conductance or resistance e Simple absolute calibration in the fie
5. Moisture 0 03 m m 3 0 2 second warm Operating range Requires 5 to 14V DC at Sensor up minimum 20 to 60 C 12mA typical 1 second warm Readings in frozen soil Voltage output O to Salinity errors up to 0 035 m m over the range O to up recommended are not meaningful 1 0V 7 O to 60 nominal 0 4 m m 50 to 500 mS m 0 5 to 5 dS m See separate po M00 data sheet eean figures apply after calibration to a specific soil type Profile Probe Measurement volumetric soil moisture content m m or vol Full accuracy O to 40 C for full Minimum supply voltage t PR2 4 ae nap achieved within accuracy specification 5 5V DC with 2m cable ypes PR2 0 0 to 0 4 mem 0 04 m3 m Typical after calibration 1 second 20 to 60 C full 7 5V with 100m a amp PR2 6 f Oto 40 C ito a specific soil type operating range Maximum 15V DC 0 0 to 0 4 m m 0 06 mim Typical using the generalised Minimum 1 Consumption Oto 40 C generalised soil calibrations second power up IP67 rated when PR2 4 lt 80 mA in normal soils recommended installed in access PR2 6 lt 120 mA Accuracy figures apply from O to 0 4 m m Full range is from 0 0 to OE a ae 4 PR2 4 or 6 PR2 6 gt 0 6 m m 100m is the maximum cable length for stated performance 0 9 cal analogue voltage accuracy Longer cables can be used and compensated for minimum outputs O to 1 0V D
6. accepts 15 input channels expandable to 60 and the memory capacity is 64k upgradable to 128k readings Moisture Meter type HH2 with spare battery E Insertion Kit type ML INK1 for use in hard soils m Carrying Case type HHCC1 to hold all items in kit Case dimensions 340 w x 85 d x 280 h mm Height includes handle See page 3 for ordering information Separate data sheet available Soil Water Potential matric potentian Loggable water filled pressure transducer tensiometers Maintenance free wide range Equitensiometers Tensiometers types SWTS3 SWT4 SWT4R and SWT5 These precision water filled ceramic cup tensiometers have good _ accuracy 0 2kPa over the range 100 to 85 kPa SWT tensiometers require refilling and degassing after dry periods and must be protected from frost The SWTAR refillable version can be filled and emptied in situ and gives best performance The SWT5 is a miniature version for plant pots for example The tensiometers require a stabilised 10 6V DC 1 3mA power source A DL2e Data Logger with a TVB1 Voltage Regulator can power and log up to 30 tensiometers or 60 with special cable arrangements For operation in drier soils gt 85kPa or in remote or inaccessible sites the Equitensiometer EQ2 should be considered Equitensiometer type EQ2 The Equitensiometer type EQ2 provides a new technique for measuring soil water potential matric potential The E
7. cylinder of radius 100mm Construction 25 4mm poly carbonate rod with stainless steel rings PR2 4 length 750mm weight 0 6kg PR2 6 length 1350mm weight 0 9kg Access tube diameter 28mm Cable standard and extension cables with M12 IP68 industrial connector Shaft lengths from 20mm to 2000mm are available See table on page 6 Connecting cables 5 10 20 or 50m ordered separately Length 215mm 40mm diameter Standard cable length 5m WMS 80mm length 23mm diameter Standard cable length 5m GYP1 36mm length 24mm diameter Standard cable length 3 0m Probe length 65mm diameter 3mm Sampling volume approx 60 x 45 x 12mm Standard cable length 2 5m A Profile Probe connected to an HH2 Moisture Meter can easily be inserted into pre installed access tubes for rapid spot measurements of the soil moisture profile The whole reading operation takes typically less than a minute at each location Not possible due to time taken for sensor to equilibrate to changes in soil water potential Not possible due to time taken for sensor to equilibrate to changes in soil water potential For continuous Scientific grade sensor Suited to research and irrigation applications A cost effective option where ML2x accuracy is not required monitoring of soil moisture the PR2 is left installed in an access tube PR2s a
8. installed in tube ready to access access tube receive Profile tube Probe ThetaProbe installed at surface ThetaProbe with 100cm extension tube Data Logger eg DL2e Logger Installed Soil Moisture Profiles An on site data logger can be connected to one or more Profile Probes for continuous monitoring of soil moisture The Profile Probes are left installed in access tubes for the duration of the logging run Most types of field data logger are suitable Installed Single Point Soil Water Content Suitable for long term soil moisture monitoring ThetaProbes are compatible with most types of data logger Other sensors may be logged at the same time to record the weather for example ThetaProbes can be surface installed or buried at depth A single logger can power and read large numbers of ThetaProbes New low cost data logging options We now offer the DL6 Soil Moisture Data Logger and the GP1 Logger Irrigation Monitor Please see separate data sheets for details ThetaKit type TK3 BASIC This portable kit contains all the items needed to make rapid spot readings of soil moisture content with a ThetaProbe The kit includes m ThetaProbe type ML2x d with 2m cable length m Spare ThetaProbe rods pack of 4 DL2e Basic Data Logger The DL2e is a simple to use field data logger capable of logging a wide range of sensors Suitably configured it is compatible with all Delta T soil moisture sensors The DL2e
9. sealed to IP68 Outputs RS232 serial 1m connector to data requires special IP65 conversion software Dimensions sampling volume and cabling Rods 60mm x 3mm diameter Overall length 207mm diameter 40mm Sampling volume approx 60mm x 30mm diameter Standard cable length 5m Portable use ThetaProbes are well suited to portable applications using the HH2 Moisture Meter to display and store soll moisture readings or water deficit readings Installed use logging ThetaProbes are low power and easy to log Sensors can be pushed into the soil surface buried at depth or used with extension tubes in augered holes Comments Versatile high accuracy sensor recognised as the gold standard for the precise determination of soil moisture content Rods 51mm long Overall length 138mm diameter 40mm Sampling volume approx 55mm x 70mm diameter Polyurethane braided cable with industrial M8 IP68 connector Standard and extension lengths available The SM200 can be used with an HH2 Moisture Meter for readout and data storage The SM200 is low power and easy to log Sensors are buriable with extension rods in augered holes For high accuracy solutions at low cost use GP1 or DL6 data loggers PR2 6 sensing depths 10 20 30 40 60 100 cm PR2 4 sensing depths 10 20 30 40 cm nominal Sampling volume 95 sensitivity within a
10. soils Low cost suited to large installations Not suitable for data logging short lifespan GYP1 Very low cost sensor suited to drier soils Relatively Measures pore water conductivity moisture content and temperature directly in the soil or substrate For all sensors except for the WET Sensor cables can be extended to a maximum length of 100m SM200 up to 55m for best accuracy Please contact Delta T if cable length is a problem Evapotranspiration Software type ET2 e FAO Penman Monteith and other Penman methods Daily or hourly P M results ETo and crop water requirements All the above methods calculate potential ET the maximum evaporative load for a non water stressed crop Elo is a vital input to the calculation of crop water needs in conjunction with other crop factors The Penman Monteith time step version offers a choice of surfaces various grasses bare soil upland conifers and water The four essential meteorological parameters are air temperature relative humidity solar radiation and wind speed Other parameters such as net radiation soil heat flux and air pressure may be used if available Input data files All data files in ASCII characters and rectangular format are compatible including weather data files from the DL2e Data Logger A wide variety of data units can be accepted e g for solar radiation sunshine duration kW m or MJ m E
11. x 3mm dia Wt 75g WET Sensor Kit The WET Sensor can be ordered as part of a complete kit that includes an HH2 Moisture Meter and carry case See Ordering Section for details Environmental Sensor sealed to IP67 Operating temperature O to 50 C Individual sensor calibrations supplied Power sid Typically 38mA for 2 5 seconds 6 10 Volts 20 MHz 5s reading 1 min temp equilibration 2 Soil Moisture accuracy specs refer to errors after applying a soil specific calibration within 10 C of calibration temperature IS N ol Pore water conductivity ECp mS m w Q O O O O O O fo 0 3 0 4 0 5 typical accuracy 5 reading max errors 10 of reading or 10 mS m typical accuracy 10 reading max errors 20 of reading or 20 mS m whichever is greater 0 6 Soil water content 0 m m Delta T gratefully acknowledges the partner organisations that have enabled the development of the WET Sensor Institute of Agricultural and Environmental Engineering IMAG BV P O Box 43 6700 AA Wageningen The Netherlands Tel 31 317 476654 Fax 31 317 425670 Website www imag wag ur nl Designers of the WET Sensor and the integrated circuit which enables accurate measurement of the permittivity and conductivity of the bulk soil or media Saint Gobain Cultil ne B V Hoekenidsehof 1 2665 JZ Postbus 4 2665 ZG Bleiswijk The Netherlands
12. C Accuracy when installed in the field will depend on soil type soil ee ah to i to homogeneity and the care taken over installation The quoted accuracy oO mm minera See separate 9 figures were obtained under uniform and controlled conditions calibration PR2 data sheet Salinity errors are included in above accuracy figures 50 to 400 mS m 0 5 to 4 dS m pore water conductivity Soil Water Potential Water filled tensiometers Tensiometers 0 2 kPa over operating Recalibration every 2 years O 1s to 99 of types SWT3 4 4R amp 5 Operates over O to Requires precision 50 C without 10 6V DC input at damage Storage 1 3mA See Installed ae nay aye Use column to 70 C SWT3 and SWT5 cannot be used Ompuls ne Te in frozen soil The SWT4 can remain installed if measuring at a frost free depth range recommended for full change Range accuracy o oe i Warmup time 10s pump required for refill an l Rue cian he ne its recalibration of SWT4 and 5 Rapid pressure SWT5 100 to 85 kPa None needed for SWT3 equilibration Refilling required after dry approx 60 periods SWT4R can be kPa h refilled and emptied in situ _ Installation dependent Soil Water Potential Porous matrix tensiometers Equitensiometer f 10 kPa from O to 100 kPa Calibration normally stable for Electrical type EQ2 10 of reading from 2 years response lt 0 5s 100 to 1000 kPa Unsuitable fo
13. PC using the RS ThetaProbe it can be ordered as part ofa Upgrading HH2 Moisture Meters 232 cable provided with each unit The Convenient kit see page opposite Newly purchased HH2 Moisture Meters can be HH2Read Windows PC software provides a The WET Sensor can also be ordered as used with all current Delta T soil moisture data import wizard for direct download into Part of a similar kit see page 7 for details sensors and with most older sensor types Excel or other PC spreadsheet packages or HH2 Moisture Meter Factory Upgrade E eerste a oe into irrigation scheduling programs Data type HH2 UPGD3 includes installation of Bs be d loaded new types of sensor Information about can also be downloaded in comma latest firmware HH2 READ PC Software upgrading can be found at www deltat co uk separated ASCII data file CSV format and current User Manual Using the HH2 with ThetaProbes and Profile Probes Soil moisture range Zero to saturation O 1 5V on voltage range Accuracy Resolution 0 13 of mV reading 1 0 mV 1 mV resolution Connection 1 x male 25 pin connector used for RS232 communications and sensor connection Sealing environment IP54 Splashproof Operating temp range 0 C 40 C ThetaProbes When used with ThetaProbes the HH2 displays and Stores single point soil moisture measurements This creates a compact system for obtaining soil moisture readings on the move and is best suited to surface me
14. Q2 makes clever use of the ThetaProbe see page 2 to obtain readings without the familiar problems of water filled tensiometers The ThetaProbe pins are embedded into a specially formulated porous matric material The Equitensiometer is compatible with most data loggers including all Delta T Loggers and the HH2 Moisture Meter Being maintenance free i e no refilling degassing or topping up required and low power the EQ2 can be conveniently used at remote sites It is not harmed by frost nor by long term burial The EQ2 achieves best accuracy over the range 100 to 1000 kPa This makes it well suited to plant water stress Studies even in very dry soils However the EQ2 should not be seen as a rapid response high accuracy device covering the full range of water potentials as such a sensor does not yet exist EQ2 equilibration time is typically several days see page 8 for further specs Extension Tubes can be used to position EQ2s at depth see ThetaProbe p 2 for details Ordering information Equitensiometer soil matric potential sensor Supplied with calibration certificate Type EQ2 w 05 5m cable Cable terminates in bare wires suitable for connection to data logger terminal blocks Type EQ2 d 05 5m cable Fitted with D socket suitable for use with HH2 unit SEG Soil and Plant Water Measurement SWT3 A y SWT4 a 3 Ordering information for water filled Tensiometers Description Range of Cerami
15. RNE 4 H il and Plant Rye Water Measurement ThetaProbe type m2x 1 accuracy or left in situ for data logging Easy data logger connection DC in DC out Excellent temperature and salinity stability Dual purpose either hand held for spot readings The ThetaProbe type ML2x measures volumetric soil moisture content to within 1 The ML2x has decisive advantages over other technologies offering precision and reliability at an affordable price Simple to use With the ThetaProbe type ML2x it s easy to make reliable accurate soil moisture measurements Simply insert the probe into the soil connect to your data logger or meter provide 5 15V DC at 20mA and within seconds you can be measuring soil moisture Calibration After a single two point gravimetric calibration ThetaProbes will meet their full 1 accuracy specification for your specific soil or other medium For convenience many users simply apply one of the two standard calibrations Supplied by Delta T With these generalised mineral or organic calibrations 5 accuracy can be achieved The ML2x has a predictable saline response which declines as salinity increases it can be used even in very saline soils up to 2000 mS m Please see the table on page 8 for further information on accuracy and calibration Applications Typical application areas include irrigation hydrology civil engineering soil water p
16. To output file The program creates a Standard ASCII file of ETo with a summary of all input data parameters There is a free choice of the synoptic hour The output file can be viewed on screen and then exported to spreadsheets etc Further information There is a demon stration version of ET2 on our website Delta T Automatic Weather Stations These are well suited to evapotranspiration Studies They are able to operate at remote and exposed sites using batteries or solar power Systems are based on the DL2e data logger Additional sensors to measure for example soil moisture and sap flow can be included This versatile logger can be expanded to over 60 channels Sap Flow Sensors and Systems Dynagages for stems and trunks 2 to 125 mm diameter TDP Granier Probes for stems and trunks 70 to gt 200 mm diameter The latest technology for measuring the sap flow and hence the water consumption of plants and trees Proven methods for measuring sap flow in greenhouses nurseries and natural environments Why measure sap flow Measuring sap flow directly is a key technique in understanding and regulating plant water relations Fields of study include irrigation agronomy commercial growing crop science hydrology tree water use water stress calculating water balances in forestry and in phytoremediation Dynagages or TDP Probes The choice is mainly determined by the diameter of the stem or trunk In the middle regi
17. UK E mail glynn gorick co uk Information on the full range of Delta T products can be found on the Internet www delta t co uk If you have any questions require advice on an application or need a quotation we will be pleased to help and can be contacted by e mail sales delta t co uk Representative 128 Low Road Burwell Cambridge CB5 OEJ England Tel 01638 742922 international 44 1638 742922 l l A co operatively owned and managed company producing Fax 01638 743155 international 44 1638 743155 instruments for environmental and industrial measurement Printed in England SPWM 09 05
18. are stainless steel rods for ThetaProbe type ML RODS 12 rods per set NB Rods are available in original style or in stronger new style Conversion kits available Please enquire before ordering Additional cable fitted to _ThetaProbe Available in multiples _of 5m only Max recommended length 100m Moisture Meter spe tz Holds multiple user defined soil types Includes PC data collection software The Moisture Meter type HH2 is a versatile readout unit for use with Delta T soil moisture sensors the Profile Probe ThetaProbe Equitensiometer and WET Sensor Simple versatile operation Use with WET Sensors The HH2 offers impressive functionality ina The HH2 can display and store the 3 outputs compact hand held unit designed for field from a WET sensor See page 7 for details use Readings are displayed on the LCD and Older versions of the HH2 have to be can be stored to memory for later upgraded before they can be used with a download to a PC Up to 2100 time WET sensor see box stamped readings can be stored The unit can be operated with one hand Ordering information a for convenience in the field Each time pena ean ea a a stamped reading includes a unique sample pul D r ry user ual i PC Software and RS232 cable number a plot identification number A to Z nia and a aes location number 1 to 255 If the HH2 is intended for use with a single Data is transferred to a
19. asurements ahi Profile Probes When used with Profile Probes the HH2 reads and Shock Maintains functional specification after 1m drop onto Stores the soil moisture content at either 4 or 6 depths simultaneously oe and can calculate the water deficit at each depth The HH2 auto EMC testing Fully complies with European EMC regulations Tested to detects the number of sensors present in each Profile Probe COMP A C552 This combination of Profile Probe and Moisture Meter provides a S ze weight 150 x 80 x 40mm 450g portable low cost system for quickly collecting soil moisture profile Battery life Typically 6500 readings for ThetaProbe type ML2x data Readings can be taken wherever access tubes have been 9V alkaline cell PPS 4500 readings for Profile Probe type PR2 6 installed Comparison of memory capacities kkkkkkkxkk Device Memory capacity User defined soil types Minimum Typical Standard generalised calibrations for mineral and organic soils are ee l ThetaProb 227 2186 supplied with the HH2 These are suitable for use with the Er a PR2 6 166 782 ThetaProbe or the Profile Probe The software also permits up to 5 Profile Probe PR2 4 22 1042 extra user defined soil calibrations to be characterised and stored for VET 04 1272 later use Minimum all reading options changed for each reading The active soil type can be switched at any time during the HH2 Output opt
20. c cup Measurement shaft lengths dims range Tensiometer general purpose type SWT3 Tensiometer superior types SWT4 and SWT4R refillable version Tensiometer miniature type SWT5 Lowest cost Water filled shaft and cup Not frost resistant More prone to thermal effects than other models standard shaft 300 or 1500mm Water filled cup only Improved frost resistance R versions are refillable in situ Standard shafts 30 and 1500mm Compact minimal soil disturbance Can be used in plant pots Water filled shaft and cup Not frost resistant Standard shaft length 70mm 50 2000mm 50mm x 10 to in 100mm 20mm dia 70 kPa increments 50mm x 100 to 20mm dia 85 kPa 50 2000mm in 100mm increments 20 200mm in 10mm increments 100 to 85 kPa 5mm x 5mm dia All SWTs are fitted with cable and male connector approx 1 5m from the pressure sensor An SWICC connecting cable must be ordered with each SWT SWTCC cables are fitted with a female connector and bare wire tails and come in lengths of 5 10 20 and 50m Lengths of up to 100m can be achieved with the SWTEC 20 extension cable 20m length The SWI4 SWT4R and SWT5 require calibration and refill service kits Please enquire for further details Low cost matric potential sensors Watermark Sensors type WMSM These granular matrix sensors have a range of O to 200 kPa They are a good choice when many replicates are required as in ir
21. curate m Designed for vertical profile measurements installation is m Can be placed at any depth in or near the root zone games and soil disturbance is minimised Compact and portable ideal for rapid measurements in turf m Provides trom 4 to 6 measuring points compared to just 1 growbags plant pots and other shallow soils and media which means a lower cost per measuring point but cannot measure lt 100mm soil depth m Rods hold the sample closer to the central measuring rod l Reduces risk of error when soils dry and crack m Using an installed array of access tubes a single PR2 probe m Can be installed horizontally in the top 50mm of soil Ealipr ONCE tale qUaniics 2 ee Mo aa m Samples a much greater volume of soil than a ThetaProbe m Better performance in saline soils N l Portable Single Point Soil Water Content A single ThetaProbe Moisture Meter Portable Soil m Moisture Profiles i YNA The HH2 Moisture Meter can take can be used with the HH2 Moisture Meter to create a compact portable system for lt making soil moisture measurements on the move a Measurements can be made at the soil surface by simply pushing the ThetaProbe s pins into the soil readings from a PR2 Profile Probe wherever access tubes have been installed With an installed array of 2 access tubes one 2 lt PR2 can provide 9 so large amounts of moisture data PR2 4 PR2 6 Empty access installedin
22. entary credit Account facilities may be available for customers placing regular orders details of these facilities and documentary credit conditions may be obtained from our Finance Department GUARANTEE AND SERVICE Delta T guarantees its products against defects in manufacture or materials for a period of 12 months from the date of delivery Full details of the guarantee terms and conditions of sale and arrangements for servicing and recalibration are available on request Delta T Devices Ltd acknowledges all manufacturers trademarks referred to in this catalogue Delta T Devices Ltd Cover Illustration Living Soil In the left foreground films of water can be seen tightly bound to the surfaces of clay particles made of crystals of quartz rock To the right at lower magnification clays silt and sand grains combine into soil crumbs held together by gels and gums produced by soll bacteria shown in yellow and by a mesh of fungus threads and plant roots This crumb Structure allows water air and roots to pass though the pore spaces On the left a decomposing root is being consumed by bacteria and fungi which them Selves supply a protein rich diet to protozoans nematodes and mites these excrete N and P salts which then become available for plant growth The pale blue line that crosses the image just below the soil profile indicates the level of water filled pores Cover illustration by Glynn Gorick Cambridge
23. ey can be placed in the soil by inserting them into augered holes or alternatively by positioning them in the wall of a trench which is then carefully back filled Optional Extension Tubes assist convenient placement and removal when burying at depth Access holes should be angled to minimise water tracking SE Soil and Plant Water Measurement New low cost logging options for 2005 DL6 and GP1 Data Loggers See separate data sheets for details Most automatic weather stations including all Delta T systems can be expanded to include one or more ThetaProbes as easily as adding say another temperature sensor Data logging and readout Most types of data logger can provide the 5 15V DC required to power the ThetaProbe and will accept its O 1V DC output signal Up to 60 ThetaProbes can be controlled and logged using the Delta T Data Logger The Moisture Meter type HH2 connects to a ThetaProbe to provide a portable system for instantaneous readout of soil moisture see pages 4 and 5 Improved rod design Since early 2003 ThetaProbes have been fitted with an improved design of rod that greatly reduces the chance of breakage A low cost conversion kit is available to allow the new rods to be fitted into older ThetaProbes ThetaProbe Dimensions 36mm 3 4 BSP thread 112mm 40mm dia Sf 3mm dia rods 4off N Soran Outstanding performance for demanding applications What do you gain when yo
24. flow provide a direct and calibrated conversion to sap velocity SV1 TDP Sap Velocity sensors output in cm hour sap velocity Probe Needle Trunk dia Vertical Heater Power Sapwood Type length dia range mm spacing voltage typ W thickness D TDP 30 30 1 2 mm 70 200 40 mm 3 0 0 2 30 70 mm D TDP 50 50 1 65 mm 100 300 40 mm 5 0 0 35 50 100 mm D TDP 80 80 1 65 mm Over 180 40 mm 7 5 0 5 gt 80 mm Logger inputs per probe 1 channel DIF lt 1mV full scale 1 channel DIF for heater voltage up to 10V full scale Cable 3 0m standard 5 or 6 wires with connector Extensions 7 6m 15m 22 8m available D AVRD Dual Adjustable Voltage Regulator type D AVRD Dynagages and TDP probes have heaters which require a continuous source of power and an adjustable voltage level to control the heater power during the initial set up The D AVRD has two independently adjustable voltage outlets suitable for all probe types Each channel outputs 1 5V to 10V max current 3A and can cope with a recommended 4 8 sensors of a similar type or voltage requirement E Soil and Plant Water Measurement phhkitrtiit k N hy ni i i L E o mains 7 DL2e sap flow system D AVRD Voltage Regulator is mounted on enclosure door Dynagages or TDP Probes have been used on Cotton corn maize sorghum soybean sugarcane sunflower sweet potato tomato
25. i collection of data and can be specified separately for each sensor UPUT ePoens _ position on a single profile probe The unconverted millivolt readings Measurement Profile Equitensio can be stored alongside the soil moisture readings Probe meter Water deficit reading Soil moisture content m m or Vol VY This reading indicates the amount of water needed in mm to restore Water deficit mm 4 the plot to field capacity across a user defined rooting depth The SACE M QUID 4 HH2 automatically calculates the water deficit based on data from a Temperature ThetaProbe or the individual sensors of a PR2 within that depth Ae T ECo Field capacity or refill point is user defined The HH2 User ee ee Manual contains tables of standard soil classifications and their SACU l Soil bulk conductivity ECb equivalent field capacity values RAE Mee Oy Wem 22 But not a typical application for the WET Sensor Selectable SE Soil and Plant Water Measurement Multi Purpose Technologies Making the best system choice Soil types environmental conditions and data collection requirements vary enormously so how can you choose the system best suited to your application The diagrams below explain some of the possibilities but Delta T and our local representatives are always willing to discuss specific applications in detail Why choose ThetaProbes Why choose Profile Probes m More ac
26. ld _ Minimises leaf stress during measurement ma lt S The AP4 Porometer measures the rate of water diffusion through leaf surfaces and calculates stomatal conductance Stomatal aperture is the dominant factor in the diffusion conductance of leaf surfaces which controls both the water loss from plant leaves and the uptake of CO for photosynthesis Measurements of diffusion conductance are therefore important indicators of plant water status and provide a valuable insight into plant growth and plant adaptation to environmental variables The AP4 measures diffusion conductance by comparing the precise rate of humidification within a small cuvette to readings obtained with a calibration plate Quoted accuracy figures for steady state porometers and gas analysis systems are based on time consuming laboratory set ups and calibrations which bear little comparison to field conditions The AP4 features simple direct calibration in the field against a tested physical standard whereas in the steady state system performance depends on the absolute accuracy of the RH measurement an error of more than 18 in the diffusion reading can be caused by a 3 RH error Further details are available on our website or in a 4 page Porometer Data Sheet which also includes a comparison between dynamic diffusion and steady state porometers Customers running the DOS version of AP4 software can now obtain the new AP4 Retrieve Windows Sof
27. on of diameters either method can be used Dynagages Microsensors are used for the tiniest stems 2 to 5 mm in diameter Stem and Trunk gauges are used for medium sized stems and branches up to 125 mm in diameter One gauge is used per stem A reasonably straight portion of stem is Dynagages for 2 to 125 mm TDP probes for 70 to gt 200 mm needed on which to mount the gauge e Measure absolute mass flow no Measure sap velocity hence TDP Granier Probes are for use with calibration required volume or mass flow stems or trunks ranging from 70 mm to Strap on sensor collar non invasive Dual stainless steel teflon coated over 200 mm in diameter For the smaller harmless conform to plant size needles trunks one probe per tree is required Sap Reliable and proven method Granier method empirical thermal velocity can vary around the circumference Constant heat energy balance dissipation technique of a tree so two probes are advisable for Re usable portable Easily inserted and removed for trees greater than 125 mm diameter and re use four probes for trees greater than 200 mm However for uniform trees in a closed into the sapwood the choice of probe canopy only one probe per tree is needed length is determined by the thickness of the TDP Probes are installed in holes drilled sapwood SF1 Dynagage Sap Flow sensors output in grams hour sap flow Gauge Example Stem dia Height Heater Power Range covered Class product range mm mm
28. r use in saline soils H 99 i Hysteresis effects may add User can check calibration but oo 20 kPa to errors unit must be returned to p PR essure equil For temp range 0 40 C Delta T for recalibration 6 kPa h we Operates over Requires 5 to 15V DC 10 to 70 C without at 20mA typically damage Minimum gt 5 5V with Buriable up to 5m deep 100m cable in soil or water Output range approx eee 150 to 550mV non linear Readings in frozen soils i i are not meaningful for O to 1000 kPa Operates over O to Requires AC excitation 80 C and device to read AC Lifespan depends on __ Output soil acidity and water flow Watermark Sensor WMSM Individual in soil calibration Not quoted type WMSM e O to 200kPa range improves performance GYPI Gypsum Block 50 to 1500 kPa range type GYP1 t N WMSM amp GYP1 Accuracy not quoted data is trend only Pore Water Conductivity WET Sensor _ Soil Moisture 0 03 Individual sensor calibrations Not continuous cui m m 3 over range supplied Generalised measurement 0 0 to 1 0 m m calibrations for Mineral Organic Reading takes Pore Water Conductivity Sand and Clay soils supplied as 55 see graph on preceding page Standard Calibrations for key greenhouse substrates available Temperature 1 0 C as an option 5 to 50 C Operates over O to Sensor is powered by 50 C the HH2 Sensor
29. re compatible with many types of data logger including Delta T Loggers Readings can also be made with an HH2 Moisture Meter if desired The tensiometers require a stabilised 10 6V DC 1 3mA power source A DL2e Logger see page 5 fitted with a TVB1 Voltage Regulator can power and log up to 30 tensiometers or 60 with special cable conns Well suited to unattended logging no maintenance is required and the sensor can be left buried long term Compatible with most data loggers Provides rapid and convenient moisture readings in a vertical soil profile Used in access tubes for easy insertion and removal Can be left installed for data logging or used with hand held Moisture Meter for multi site portable readings Precision trusted range of sensors Accurate in wetter soils well suited to irrigation scheduling and the study of water uptake and water movement Require maintenance For measurement of matric potential Zero maintenance Best accuracy in dry soils Can be left installed in frozen soils potential Designed to be used Not possible due to time taken for sensor to equilibrate to changes in soil water with an HH2 for convenient portable operation Resistance sensors requiring AC current and a device to read the AC output A suitably specified DL2e Logger can perform both functions WMSM for irrigated and other wet
30. rigation monitoring for example They are more durable in soil than gypsum block sensors Ordering Information Watermark Sensor type WMSM 5m cable Gypsum Block wena J Sensors type GYP1 amp Gypsum Block Sensors measure from 50 to 1500 kPa They have a relatively short operating life They are better suited to dry soils than wet soils Ordering information Gypsum Soil Moisture Blocks type GYP 1 set of 5 blocks each fitted with 3 5m cable It is important to note that although both of the above electrical resistance sensors are inexpensive the overall cost is increased by the need to include an AC excitation current and a device to read the AC output A suitably specified DL2e Data Logger can perform both functions Comparison of matric potential ranges Sensor Type EQ2 GYP1 WMSM SWTs Suction kPa log scale Specifications For all products on this page please see Comparative Specifications page 8 Developed by Dr Liu Patent application no 19629745 1 WE T S eC Ns Or type WET 2 Multi parameter soil sensor Moisture and nutrient content in the root zone The WET Sensor measures three vital soil properties Water content Electrical conductivity EC and Temperature Applications The WET Sensor has applications in precision horticulture and soil science research and is usable in both soils and growing substrates It is unique in its ability to measure pore water conductivity ECp
31. rofiling pollution monitoring remote sensing validation and forestry Wherever a vertical soil moisture profile is required Profile Probes should be considered see PR2 data sheet however it should be noted that ThetaProbe accuracy is 1 compared to the Profile Probe s 3 NSS t AAN AIAN NAAN pa aoa ES Sa ce E E I e f H oF Installation and agriculture ThetaProbes can be used in a wide range of soils composting and other growing media Because they are so compact ThetaProbes can be inserted into plant pots or may be positioned horizontally in a seed tray they require a minimum 5Omm depth of compost Horticulture Composting The ML2x can be placed in composting material where it can tolerate temperatures up to 0 C The accuracy between 40 and 70 C is 2 but media density and contaminant levels may affect the accuracy attainable and the lifespan of the probe Irrigation Accuracy ease of use and speed of response make the ThetaProbe well Suited to irrigation applications Readings can be used to optimise irrigation scheduling or ThetaProbes can be installed as part of an automatic irrigation system Environmental monitoring Long term studies of global climate and local environments require the monitoring of land atmosphere interactions and soil water is increasingly seen as one of the critical components SIMIAN WALA V NANA ThetaProbes are robust buriable and maintenance free Th
32. spects an even better alternative to neutron probes see PR2 data sheet Further information Latest developments are announced on our web site www delta t co uk The ThetaProbe has been jointly developed with the Macaulay Land Use Research Institute MLURI as originally described in ThetaProbe ML2 Principles of Operation and Applications J D Miller amp G J Gaskin Patents UK patent 2300485B US patent 5804976 Patent applied for EUR 96303190 1 Ordering information ThetaProbes are available with 3 alternative cable terminations as follows ThetaProbe bare wires 5m cable Cable terminates with bare wires suitable for direct connection to terminal blocks ThetaProbe D socket 5m cable Fitted with 25 way D socket suitable for use with HH2 Moisture Meter ThetaProbe IP68 plug 5m cable Fitted with latching IP68 connecting plug Suitable for connecting to HH2 Moisture Meters when fitted with C HH2 T connector Thetakit v3 Portable soil moisture _measuring kit Includes ThetaProbe ML2x d 02 2m cable pack of 4 x spare stainless steel rods Moisture Meter HH2 Insertion Kit MLINK1 Extension Tubes The ML2x t should be used whenever it is intended to use Extension Tubes with an HH2 Moisture Meter the ML2x d is NOT suitable for use with Extension Tubes 50cm Extension Tube for ThetaProbe type ML EX50 100cm Extension Tube for ThetaProbe type ML EX100 Pack of sp
33. tware free of charge as a download from www delta t co uk Ordering Information Details regarding ordering information accessories consumables and spares for our instruments can be found in our price lists available on request and also on our web site at www delta t co uk UK customers SALES AND TECHNICAL ENQUIRIES should be made directly to Delta T in Burwell PRICES are available on request and a detailed quotation can be provided if required PAYMENT for new customers we usually ask for payment in advance Account facilities are available for customers placing regular orders details may be obtained from our Finance Department Customers outside the UK OVERSEAS REPRESENTATION Delta T has an extensive network of representatives to serve customers outside the UK In these countries all sales and technical enquiries should be directed to our representatives details are available DIRECT SUPPLY if there is no Delta T representative in your country we will supply you directly from the UK Export sales account for more than three quarters of our business and we have many years experience of dealing with enquiries from overseas Clients PRICES are available on request from Delta T or your local representative Detailed quotations can also be provided when needed including costs for freight insurance and documentation PAYMENT our normal terms are payment in advance of shipment or by irrevocable docum
34. u choose the ThetaProbe Description DC in DC out 100MHz signal Standing wave measurement 4 Rod arrangement Replacement rods Cylindrical shape Delta T support AT For technical specifications see table across pages 8 and 9 Requires 5 to 15V DC at 20mA Provides O to 1V DC output Compatible with HH2 Moisture Meter and most data loggers With frequencies below 30MHz salinity effects can be a problem With frequencies above 250MHz measuring bound water in clay soils is a problem 1OOMHz is an excellent compromise Simple elegant circuit responds precisely to the dielectric properties of soil 3 rods are arranged in a Circle around a central rod This creates a defined cylindrical zone of measurement 60mm long x 26 5mm diameter 300mm Made of 3mm diameter resilient 304 austenitic Stainless steel with Sharpened tips Rods have threaded ends that screw into ThetaProbe body The ThetaProbe casing is a 40mm diameter tube with threaded end Extension tubes 500 and 1000 mm screw onto this thread Case is robust and sealed to IP68 standard Overall length of probe is 207mm Thousands of ThetaProbes are in use all over the world The latest ML2x includes improvements suggested by customer feedback Advantage Dual purpose for burial and data logging
35. voltage typ W nominal dia Microsensor D SGA3 2 7 4 0 35 2 3 0 05 293 9 Stem Gauge D SGA13 12 16 70 4 0 0 15 9 10 13 16 19 25 Trunk Gauge D SGB50 45 65 305 6 0 1 4 35 50 70 100 Logger inputs per gauge 3 channels DIF lt 1mV full scale 1 channel DIF for heater voltage lt 10V full scale Cable 1 5m standard 8 wires with connector Extensions 7 6m 15m 22 8m 30 5m available Measurement principles Both types of sensor use a constant heat input but they derive their results in different ways They are not heat pulse methods Dynagages consist of a heater element which is strapped round the stem of the plant and insulated from the ambient conditions The plants are heated typically only 1 to 5 C Thermocouples built in to the gauge measure the heat carried away by the sap flow which can be converted into real time sap flow in g h or kg h This is an absolute measurement and does not require calibration The principles of the heat balance method have been scientifically proven over many years and references exist for many major crops and tree species TDP probes feature improved needles used with the Granier technique ref 1 Each probe has two thermocouple needles which are inserted into the sapwood the upper one containing an electric heater The needles measure the temperature difference dT between the heated needle and the sapwood ambient temperature below The dT variable and the maximum dTm at zero
36. w minutes We recommend that an HH2 is dedicated to each WET Sensor WET Substrate Calibrations Upgrade type WET GH 1 Upgrade of HH2 Moisture Meter with WET substrate calibrations suitable for a variety of horticultural media NB calibrations are factory installed into the HH2 at Delta T premises they are not installed into the WET Sensor itself S O I Wa te r M eC ad S u r eC m eC nt specifications and comparisons Accuracy amp range Calibration Response amp Environmental Input and output stabilisation time Soil Water Content ThetaProbe type ML2x 0 01 m m 1 O to 40 C After calibration to a specific Response lt 0 5s Operates over 10 to Requires 5 to 15V DC 0 02 m m 2 40 to 70 C soil type to 99 of 70 C without damage at 20mA typical Using generalised soil change Buriable up to 2m deep Minimum gt 9 9V with calibrations supplied ls warm up is in soil or water For use 100m cable dvised at greater depth Voltage output O to Accuracy figures apply over the range 0 05 to 0 6 m m a Full rea ane fice E a ae 8 Full accuracy contact Delta T 1V DC for 0 to 0 6 oe ae achieved within Readings in frozen soils almost linear Salinity errors from 0 0 to 250 mS m lt 0 0001 m m 5s are not meaningful Compatible with most change per mS m Minimal change beyond 250 mS m Can data loggers a calibrated up to 2000 mS m SM200 Soil
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