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Model 201 and 208 Digital Thermometer

1. l entere Irene rore Ln ee inn 4 1 4 0 Genetal EE et ede 4 1 4 1 Serial Interface i 4 1 4 1 1 Serial Interface Connections ieke nee 4 1 4 1 2 Serial Interface Operation see ee ee 4 3 4 1 3 Sample Basic Program eene 4 4 4 1 4 Sample QuickBasic 4 0 Program 4 4 4 2 Serial Interface Command Summary 4 5 5 SERVICE a zza RZA anni sedisse 5 1 5 0 General RE RD sian 5 1 5 1 Model 201 Rear Panel Connections 5 1 5 2 Model 208 Rear Panel Connections 5 2 5 3 Error Code Troubleshooting 5 3 5 4 General Maintenance aaa eeeceh 5 4 5 5 Fuse Replacement ii 5 4 5 6 Line Voltage Configuration 5 4 5 7 Recalibration esses 5 5 5 7 1 Current Source Calibration ee 5 6 5 7 2 A D Converter Calibration reren 5 6 5 8 Serial Interface Cable and Adapters 5 7 6 OPTIONS AND ACCESSORIES eese 6 1 6 0 General iet RE N 6 1 6 1 Model8 EE EE a ai cm lettres 6 1 6 2 AGCESS NIES 1 reci AE iii 6 1 6 3 Wires Eee eui 6 3 6 4 SENSOIS 2 E 6 3 APPENDIX A GLOSSARY OF TERMINOLOGY A 1 APPENDIX B HANDLING OF LHe amp LN2 B 1 B1 0 General
2. USER S MANUAL Model 201 ana 208 Digital Thermometer Includes Coverage For Model 201 Single Channel Thermometer Model 208 Eight Channel Thermometer akeShore Lake Shore Cryotronics Inc 575 McCorkle Boulevard Westerville Ohio 43082 8888 USA E Mail Addresses sales lakeshore com service lakeshore com Visit Our Website www lakeshore com Fax 614 891 1392 Telephone 614 891 2243 Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics Inc No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics Inc in these developments Methods and apparatus disclosed herein may be subject to U S Patents existing or applied for Lake Shore Cryotronics Inc reserves the right to add improve modify or withdraw functions design modifications or products at any time without notice Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing performance or use of this material Rev 1 0 P N 119 018 4 November 1999 Lake Shore Model 201 208 User s Manual LIMITED WARRANTY Lake Shore Cryotronics Inc henceforth Lake Shore the manufacturer warrants this product for a period of 12 months from the date of shipment During the warranty period under authorized return of instruments
3. Remote Operation 4 7 Lake Shore Model 201 208 User s Manual Serial Interface Commands Continued YH End Scanning Model 208 Only Input YH Returned Nothing Remarks For a Model 208 only stops the scan of the inputs from the input channel which it is currently on The scanner should be on hold when any of the other scanner commands are sent to the scanner or unpredictable results could occur WS Sample Sensor Reading and Alarm Status Input WS Returned The following is returned for a Model 201 sign sensor reading units alarm status CR LF The following is returned for a Model 208 current channel sign sensor reading units alarm status CR LF Remarks Gives the sample sensor reading and the alarm status For the alarm status parameter A indicates active while l indicates inactive 4 8 Remote Operation Lake Shore Model 201 208 User s Manual Serial Interface Commands Continued WA Input Returned Remarks WY Input Returned Remarks Switch ID and Alarm Data WA The following is returned for a Model 201 switch ID high or low alarm alarm sign alarm setpoint CR LF The following is returned for a Model 208 switch ID high or low alarm alarm sign alarm setpoint active channel number CR LF Provides the switch ID and alarm data The switch ID parameter is 0 through 3 for the Model 201 Its the sum of 1 if the alarm set enable is set plus 2 if r
4. fee You can recalibrate the thermometer to original specifications but Lake Shore will not warrant these calibrations Recalibration requires a digital voltmeter DVM with 4 digit resolution or better and 25 KO and 125 KO precision resistors with 0 01 tolerance or better Recalibration involves current source and analog digital A D converter calibration A D calibration will erase all SoftCal compensations and must be done after current source calibration and not before Service 5 5 5 7 1 Lake Shore Model 201 208 User s Manual Current Source Calibration 1 2 3 Allow 30 minute warm up to achieve rated specifications Configure 125 kO resistor as shown in Figure 5 4 Model 208s should be on channel 1 Connect the voltage leads of the DVM across the resistor and adjust the ADJ trimpot located on rear panel until DVM displays a voltage of 1 2500 volts 100 microvolts Remove DVM and resistor A Ne 1 2 18 wmm T ANA MV W 2 NOTE Do not use a voltmeter for A D converter calibration 5 7 2 D 201 U 5 4 Figure 5 4 Calibration Connections A D Converter Calibration NOTE Current source calibration must be performed before A D converter calibration Allow 30 minute warm up to achieve rated specifications Perform current source calibration Configure 125 kO resistor as shown in Figure 5 4 Model 208s should be on channel 1 Wait 10 seconds for
5. or component parts to Lake Shore freight prepaid the company will repair or at its option replace any part found to be defective in material or workmanship without charge to the Owner for parts service labor or associated customary shipping cost Replacement or repaired parts will be warranted for only the unexpired portion of the original warranty All products are thoroughly tested and calibrated to published specifications prior to shipment Calibration Certifications are offered for 6 month periods only Where such documentation must be updated a re certification service is offered by Lake Shore at a reasonable cost LIMITATION OF WARRANTY This warranty is limited to Lake Shore products purchased and installed in the United States This same protection will extend to any subsequent owner during the warranty period It does not apply to damage caused by accident misuse fire flood or acts of God from failure to properly install operate or maintain the product in accordance with the printed instructions provided This warranty does not apply to defects resulting from improper or inadequate maintenance unauthorized modification or misuse operation outside of the environmental specifications for any product or part or buyer supplied software interfacing THIS WARRANTY IS IN LIEU OF ANY OTHER WARRANTIES EXPRESSED OR IMPLIED INCLUDING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WHICH ARE EXPRESSLY EXCLUDED THE OWNER AGREES
6. several tenths of a kelvin To determine if this is a problem in your measurement system perform either of the two following procedures 1 Place a capacitor across the diode to shunt the induced AC currents The size of the capacitor used will depend on the frequency of the noise If the noise is related to the power line frequency use a 10 HF capacitor If AC coupled digital noise is suspected digital circuits or interfaces then use a capacitor in the range of 0 1 to 1 HF In either case if the resultant DC voltage measured is observed to increase there is induced noise in your measurement system Installation Lake Shore Model 201 208 User s Manual Measurement Errors Due To AC Noise Continued 2 Measure the AC voltage across the diode with an AC voltmeter or oscilloscope Note that most voltmeters will not have the frequency response to measure noise associated with digital circuits or interfaces which operate in the MHz range A thorough discussion of this potential problem and the magnitude of error which may result is given in the paper Measurement System Induced Errors In Diode Thermometry J K Krause and B C Dodrill Rev Sci Instr 57 4 661 April 1986 which is available from Lake Shore upon request The potential for this type of error can be greatly reduced by connecting twisted leads pairs between the measurement instruments and the diode sensors when an AC noise environment exists We recommend the
7. the Model 201 208 are included in this paragraph Please refer to the Lake Shore Product Catalog for installation details and sensor specifications Call Lake Shore for copies of application notes or with questions or comments concerning sensor installation The following are general recommendations on sensor installation 1 Do not ground the sensor 2 Shield the leads and connect the shield wire to SHIELD on the screw terminal connector only Do not connect shield at the other end of the cable 3 Keep leads as short as possible 4 Use twisted pair wire Use of Lake Shore Duo Twist wire or equivalent for two wire or Quad Twist wire or equivalent for four wire applications is strongly recommended 5 Lead wires should be thermally anchored Paragraph 2 4 1 discusses two lead versus four lead measurements Paragraph 2 4 2 discusses connecting leads Sensor mounting is covered in Paragraph 2 4 3 Finally Paragraph 2 4 4 describes the effect of measurement errors due to AC noise Two Lead Versus Four Lead Measurements In the two lead measurement scheme the leads used to measure the sensor voltage are also the current carrying leads The resultant voltage measured at the instrument is the sum of the temperature sensor voltage and the IR voltage drop within the two current leads Since in a cryogenic environment the flow of heat down the leads can be of critical concern normally wire of small diameter and significant
8. the alarm temperature After 15 seconds the alarm setpoint temperature will display If more than one point is desired go back to step 5 Note that one point may be entered between 1 4 K to 9 9 K No point may be entered between 10 K and 40 K Two points may be entered above 40 K Return the SET switch to position O Lake Shore Model 201 208 User s Manual 3 6 2 Verifying SoftCal Operation The status of SoftCal can be checked by holding the UNITS key for 2 to 3 seconds If SoftCal is not in operation 00 6 will display If the first digit of the display is 1 SoftCal is set for below 28 K If either the second or third digit is 1 SoftCal is set for above 28 K 3 6 3 Erasing SoftCal Compensations When SoftCal compensations are erased the thermometer returns to normal operation Move the SET switch to position 1 2 Use the UNITS key to change the front panel display to 0 This key is a toggle If the display moves in the wrong direction release and press again 3 Press the CAL ENABLE button on rear panel using a pen tip The display will change from 0 to 50 F The alarm setpoint will display after the SoftCal compensation has been erased 4 Move the SET switch to position O 3 6 Operation 4 0 4 1 4 1 1 Lake Shore Model 201 208 User s Manual CHAPTER 4 REMOTE OPERATION GENERAL The Model 201 208 Digital Thermometer has a built in Serial Interface that can be used for operational and service purpos
9. 0 62754 2 26440 i 1 05136 0 61333 2 23248 1 03951 0 59901 2 20480 1 02744 0 58502 2 17716 1 01475 0 57099 2 14994 1 00193 0 55715 2 12245 i 0 98892 0 54327 2 10065 0 98264 0 52983 2 07844 0 97557 0 51639 2 03712 0 96216 0 50302 1 99736 0 94877 0 48965 1 95641 0 93535 0 47625 1 91202 0 92166 0 46292 1 85236 0 90798 0 44925 1 79177 0 89426 0 43559 1 73193 0 88052 0 42178 1 66870 0 86676 0 40797 1 59215 0 85298 0 39375 1 51169 0 83936 0 37951 1 43234 0 82531 0 36515 1 34993 0 81142 0 35078 1 28434 0 79749 0 33599 1 23212 0 78351 0 32121 1 18995 0 76950 0 30643 1 16027 0 75544 0 29159 1 14015 0 74135 0 27665 1 12689 C 2 Curve Tables Lake Shore Model 201 208 User s Manual Table C 3 Curve 2 DT 500DRC D Voltage Temp Characteristics Temp PROM Temp PROM BP K Voltage BP K Voltage BP K Voltage 0 70757 0 69344 0 67931 0 65518 0 65105 0 63693 0 62280 0 60867 0 59455 0 58080 0 56707 0 55334 0 53960 0 52649 0 51337 0 50026 0 48714 0 47403 0 46057 0 44711 0 43365 0 42019 0 40613 0 39208 0 37802 0 36397 0 34940 0 33482 0 32025 0 30568 0 29111 0 27654 0 26197 0 24739 0 23325 0 21911 0 20497 0 19083 0 17774 0 16464 0 15155 DENS AA ER ND OOONOU AR Curve Tables C 3 Lake Shore Model 201 208 User s Manual Table C 4 Curve 3 DT 500DRC E1 Voltage Temp Characteristics Temp PROM Temp PROM Temp PROM BP K Voltage BP K Voltage BP K Voltage DO
10. 1 The setpoint will be indicated in the display In order to change the setpoint 1 Make sure the SET switch is in position 1 2 Hold the UNITS key until the desired temperature is reached UNITS is a toggle If the UNITS key is released and pressed again the temperature direction is reversed When the temperature display is increasing the alarm will be a high setpoint If temperature display is decreasing the alarm will be a low setpoint 3 Release the UNITS key when the desired setpoint is reached For a Model 208 press the CHANNEL key to set the alarm for each channel displayed in the channel window and repeat the steps above Move the SET switch back to position 0 The alarm is now enabled When it is triggered an alarm status light will appear in the upper left of the temperature display The alarm can be connected to another device which will be triggered when the alarm is activated The three contact terminal block is present on the rear panel as J3 ALARM The alarm contacts are designated 1 COM 2 with 1 representing the normally open state and 2 representing the normally closed state Operation 3 3 8 5 2 3 5 3 3 6 Lake Shore Model 201 208 User s Manual Latched And Unlatched Alarms Alarms can be either latched or unlatched The alarm is latched when the LATCH switch is in position 1 The alarm will turn on when triggered by the alarm setpoint but will not automatically turn off when the temperature drops
11. 1 08105 1 07748 1 07402 1 07053 1 06700 1 06346 1 05988 1 05629 1 05277 1 04353 Temp PROM BP K Voltage 1 03425 1 02482 1 02044 1 01525 1 00552 0 99565 0 98574 0 97550 0 96524 0 95487 0 94455 0 93383 0 92317 0 91243 0 90161 0 89082 0 87976 0 86873 0 85764 0 84650 0 83541 0 82404 0 81274 0 80138 0 78999 0 77855 0 76717 0 75554 0 74398 0 73238 0 72075 0 70908 0 69737 0 68580 0 67387 0 66208 0 65026 0 63841 0 62654 0 61465 0 60273 0 59080 0 57886 0 56707 0 55492 0 54294 0 53093 0 51892 C 7 Lake Shore Model 201 208 User s Manual Table C 7 Curve 6 DT 470 Voltage Temp Characteristics Continued Temp PROM Temp PROM Temp PROM BP K Voltage BP K Voltage BP K Voltage 0 50689 0 36110 0 21212 0 49484 0 34881 0 19961 0 48278 0 33650 0 18696 0 47069 0 32416 0 17464 0 45858 0 31180 0 16221 0 44647 0 29958 0 14985 0 43435 0 28700 0 13759 0 42238 0 27456 0 12536 0 41003 0 26211 0 11356 0 39783 0 24963 0 10191 0 38561 0 23714 0 09032 0 37337 0 22463 C 8 Curve Tables w NOTES cz Lake Shore is a technology leader in the development of cryogenic temperature sensors precision low temperature measurement and control instrumentation and magnetic measurement and test Systems Since 1968 Lake Shore physicists material scientists and engineers have dedicated themselves to the development of tomorrow s technology today Lake Shore serves a worldwide network
12. 2 and safety symbols in Paragraph 1 3 If you have just received your new Model 201 208 please proceed to Chapter 2 and become familiar with the installation instructions Complete and detailed instrument and sensor operational information is contained in Chapter 3 Remote operation is outlined in Chapter 4 Limited service and rear panel connector definitions are contained in Chapter 5 Chapter 6 provides information on options and accessories Appendix A is a Glossary of Terminology Handling of Liquid Helium and Liquid Nitrogen is provided in Appendix B Finally details on sensor curves are provided in Appendix C 1 4 GENERAL DESCRIPTION The Model 201 208 Digital Thermometers are ideal for monitoring critical temperature conditions in areas such as chemical investigation materials research superconductivity measurements and in low temperature physics The units feature e Broad Temperature Range 1 4 K to 475 K 272 C to 202 C e Single Channel 201 and Eight Channel 208 Models e For Use with Lake Shore DT 470 Series DT 500 Series and other Silicon Diode Sensors e System Accuracy Instrument with Sensor with SoftCal to within 0 1 C or better e Displays Temperature in C F or K or in Sensor Voltage e High Low Alarm Setpoint with Interfacing Alarm Contacts e Standard RS 232C Output of Temperature Input of Settings and Alarm Status For Remote Operation Introduction 1 1 Lake Shore Model 201 208 U
13. 3 mK but because of the lower sensitivity dV dT of the diode at higher temperatures it becomes 10 mK at liquid nitrogen temperature Connecting Leads To The Sensor An excessive heat flow through the connecting leads to any temperature sensor can create a situation where the active sensing element is at a different temperature than the sample to which the sensor is mounted This is then reflected as a real temperature offset between what is measured and the true sample temperature Such temperature errors can be eliminated by proper selection and installation of the connecting leads Installation Lake Shore Model 201 208 User s Manual Connecting Leads To The Sensor Continued 2 4 3 In order to minimize any heat flow through the leads the leads should be of small diameter and low thermal conductivity Phosphor bronze or Manganin wire is commonly used in sizes 32 or 36 AWG These wires have a fairly low thermal conductivity yet the electrical resistivities are not so large as to create any problems in measurements Lead wires should also be thermally anchored at several temperatures between room temperature and cryogenic temperatures to guarantee that heat is not being conducted through the leads to the sensor Sensor Mounting Before installing a diode sensor identify which lead is the anode and which is the cathode When viewed with the base down and with the leads towards the observer the positive lead anode is o
14. 5 4 8 V 4 26 l 4 9 V 5 27 l 5 10 V 5 28 l 5 11 V 6 29 l 6 12 V 6 30 l 6 13 V 7 31 l 7 14 V 7 32 l 7 15 V 8 33 l 8 16 V 8 34 l 8 17 Shield 35 Shield 18 Shield 36 Shield Figure 2 2 Model 208 D Sensor Connector Details 2 8 Installation 2 6 2 7 Lake Shore Model 201 208 User s Manual SENSOR CURVE DEFINITION In order for the instrument to display accurate temperature a response curve that matches the sensor being used must be selected Seven standard curves are stored within the Model 201 208 Different curves may be assigned to each channel of the Model 208 The curves are numbered 0 through 6 and are detailed in Appendix C The curve the unit is configured for is listed on the inside of the front cover Curve 6 DT 470 Curve 10 is the standard curve which will be selected unless specified differently upon ordering To determine which curve is selected press and hold the UNITS key and turn on 1 the rear panel SET switch DIP switch 3 Release the UNITS key The 201 will now display the curve number in the display window The Model 208 will display the curve number in the display window and the channel number in the channel window In order to display curves for the other channel numbers in the Model 208 simply press the CHANNEL key and scroll through the eight channels To change the curve press the UNITS key The instrument will scroll through curves 0 through 6 In the Mo
15. 5 10 30 or 60 seconds A dwell time of 0 instructs the thermometer to skip that particular channel To set the dwell Hold the CHANNEL key 3 for seconds Do not release 2 After 3 seconds while still pressing CHANNEL use the UNITS key to select the desired time 0 skip 5 10 30 or 60 seconds 3 Repeat the procedure for each desired channel The default channel dwell is 5 seconds BEBEB VLC Lake Shore Cryotronics 201 THERMOMETER P 201 1 1 bmp Figure 3 1 Model 201 Front Panel BEBH IC CHANNEL X ON Lake Shore Cryotronics nn JL OFF 208 THERMOMETER P 201 1 2 bmp Figure 3 2 Model 208 Front Panel 3 2 Operation 3 5 3 5 1 Lake Shore Model 201 208 User s Manual ALARM OPERATION Operation of the Model 201 208 alarm is detailed in the following paragraphs Alarm setpoint is described in Paragraph 3 5 1 latched and unlatched alarms in Paragraph 3 5 2 and the alarm fix function Model 208 only in Paragraph 3 5 3 Alarm Setpoint The alarm setpoint is a temperature which activates the alarm relay The alarm setpoint can be set to warn of temperatures rising above a certain point high alarm or falling below a certain point low alarm NOTE Alarm setpoints work for temperatures not voltage If in voltage mode while setting an alarm setpoint the thermometer will default to kelvin for the alarm setpoint To display the alarm setpoint move the SET switch on the rear panel to position
16. Alarm Setpoint Value Lxxx x Nothing Used to select the low alarm setpoint value where xxx x equals the temperature setpoint Units will be as specified by command FO If the instrument is set for voltage units the alarm will default to kelvin units L31 2 term sets a low alarm setpoint of 31 2 degrees Alarm Reset R Nothing Used to reset the alarm Remote Operation Lake Shore Model 201 208 User s Manual Serial Interface Commands Continued Y Input Returned Remarks Example YC Input Returned Remarks YS Input Returned Remarks Channel Dwell Time Model 208 Only Yab Nothing On a Model 208 only this command is used to set the dwell time for a given channel where a equals the channel 1 8 and b equals the dwell time parameter as follows 0 0 seconds 1 5 seconds 2 10 seconds 3 30 seconds 4 60 seconds Setting the dwell time to 0 causes the channel be skipped in the sequence Y23 term selects channel 2 and sets the dwell time for 30 seconds Channel Scanner Channel Model 208 Only YCx Nothing For a Model 208 only this command asynchronously selects a scanner channel for readout independent of the scan feature where x equals channel 1 8 Begin Scanning Model 208 Only YS Nothing For a Model 208 only starts the scan of the inputs from the input channel which it is currently on The instrument skips every channel with a dwell time of zero
17. C 6 and Curve 6 DT 470 Curve 10 in Table C 7 Table C 1 Curve 0 DT 500DI 8B Voltage Temp Characteristics Temp PROM Temp PROM Temp PROM BP K Voltage BP K Voltage BP K Voltage 2 41773 1 11353 0 73733 2 40475 1 10729 0 72353 2 39217 1 09810 0 70936 2 37946 1 09125 0 69532 2 36668 1 08547 0 68125 2 35378 i 1 08038 0 66713 2 32126 1 07549 0 65302 2 28869 1 06400 0 63889 2 25643 i 1 05273 0 62475 2 22480 1 04123 0 61066 2 19395 1 02954 0 59646 2 16053 i 1 01748 0 58262 2 13552 1 00528 0 56877 2 10809 0 99263 0 55504 2 08197 0 98666 0 54136 2 05687 0 97988 0 52801 2 00852 x 0 96711 0 51469 1 96003 0 95397 0 50155 1 90579 0 94086 0 48815 1 85614 0 92767 0 47486 1 80479 0 91443 0 46148 1 74703 0 90124 0 44800 1 67479 0 88776 0 43451 1 60665 0 87434 0 42064 1 53675 0 86087 0 40675 1 46370 0 84735 0 39274 1 38832 0 83377 0 37875 1 31868 0 82032 0 36436 1 26476 0 80647 0 35002 1 21712 0 79274 0 33559 1 17857 0 77896 0 32109 1 15106 0 76513 0 30656 1 13317 0 75125 0 29222 1 12169 Curve Tables C 1 Lake Shore Model 201 208 User s Manual Table C 2 Curve 1 DT 500DI 8A Voltage Temp Characteristics Temp PROM Temp PROM Temp PROM BP K Voltage BP K Voltage BP K Voltage 2 46386 1 11741 0 72739 2 44821 i 1 11007 0 71308 2 43188 i 1 09942 0 69891 2 41500 1 09178 0 68469 2 39781 A 1 08559 0 67043 2 37578 1 07992 0 65615 2 33823 1 07502 0 64185 2 29906 1 06307
18. C Connector Single Channel Digital Thermometer configured for 200 250 VAC Includes one Model 201 MC Connector Eight Channel Digital Thermometer configured for 90 140 VAC Includes one Model 208 MC Connector 208 230 Eight Channel Digital Thermometer configured for 200 250 VAC Includes one Model 208 MC Connector 6 2 ACCESSORIES A list of accessories available for the Model 201 208 are as follows Model Description of Accessory RJ 11 to RJ 11 Cable Assembly 10 feet 3 meters See Figure 6 1 RJ 11 to DB 25 Adapter Connects RJ 11 to Serial Port on rear of computer See Figure 6 2 RJ 11 to DE 9 Adapter Connects RJ 11 to Serial Port on rear of computer See Figure 6 3 Calibration connector set for Model 201 only Calibration connector set for Model 208 only Screw Terminal Adapter Used with Model 208 for convenient connection to multiple sensor probe assemblies with stripped ends that will not be permanently wired Provision for attachment to top of thermometer Fitted with D type mating connector Options amp Accessories 6 1 Lake Shore Model 201 208 User s Manual Accessories Continued Description of Accessory Sensor Probe 4 inches 10 cm long by 1 8 inch 3 2 mm diameter stainless steel probe with 6 foot 1 83 meter cable with 4 stripped ends Sensor Probe 4 inches 10 cm long by 1 8 inch 3 2 mm diameter stainless steel probe with 6 foot 1 83 meter cable with 4 pin 201
19. EE t Re EE ala B 1 B2 0 ierit EE N RE aia B 1 B3 0 Handling Cryogenic Storage Dewars B 1 B4 0 LHe and LN Safety Precautions iese esse ees ese ee ee B 1 B5 0 Recommended First Aid ee ee ee Re ee B 2 APPENDIX C CURVE TABLES esses C 1 C1 0 General set ne bid ies C 1 ii Table of Contents Lake Shore Model 201 208 User s Manual LIST OF ILLUSTRATIONS Figure No 1 1 Model 201 Front Panel 1 2 Model 208 Front Panel 1 3 Model 2308 12 Case Physical Dimensions 1 10 2 1 Model 201 Sensor Connector J1 Details 2 7 2 2 Model 208 Sensor Connector J1 Details 2 8 2 3 Model 2090 Rack Mounting aaa eaaaaannianaae 2 10 3 1 Model 201 Front Panel 3 2 Model 208 Front Panel 4 1 Serial VO RJ 11 Connector Pin Definitions 4 2 4 2 Serial Interface Connections iese ee Re RR Re 4 2 5 1 Model 201 Rear Panel Connections esse ee ee ee 5 1 5 2 Model 208 Rear Panel Connections ee ee ee 5 2 5 3 Line Voltage Jumper Configuration 5 4 Calibration Connections see ee Re Re m 5 5 Model 2001 RJ 11 Cable Assembly Wiring Details 5 7 5 6 Model 2002 RJ 11 to DB 25 Adapter Wiring Details 5 7 5 7 Model 2003 RJ 11 to DB 9 Adapter Wiring Details 5 8 6 1 Model 2001 RJ 11 Cabl
20. Introduction 2 0 2 1 2 2 Lake Shore Model 201 208 User s Manual CHAPTER 2 INSTALLATION GENERAL This chapter provides installation instructions for the Model 201 208 Digital Thermometer Inspection and unpacking instructions are provided in Paragraph 2 1 repackaging for shipment in Paragraph 2 2 sensor installation recommendations in Paragraph 2 3 power and ground requirements in Paragraph 2 4 sensor curve definitions in Paragraph 2 5 and rack mounting details in Paragraph 2 6 INSPECTION AND UNPACKING Inspect shipping containers for external damage Claims for damage apparent or concealed or partial loss of shipment must be made in writing to Lake Shore within 5 days from receipt of goods If damage or loss is apparent please notify the shipping agent immediately Open the shipping container A packing list is included with the instrument to simplify checking that the unit sensor accessories and manual were received Please use the packing list and the spaces provided to check off each item as the instrument is unpacked Inspect for damage Be sure to inventory all components supplied before discarding any shipping materials If there is damage to the instrument in transit be sure to file proper claims promptly with the carrier and insurance company Please advise Lake Shore Cryotronics of such filings In case of parts or accessory shortages advise Lake Shore immediately Lake Shore cannot be responsible for any m
21. K Sensor Excitation 10 uA constant current Repeatability 50 mK Input Range 0 to 3 volts with a resolution of 0 1 millivolts Hi Lo Alarm Setpoint 0 1 resolution Alarm Relay Single SPDT relay rated 28 VDC or Peak AC 0 25A 3 W max Scan Dwell The Model 208 automatically scans all eight channels with selectable dwell times of 0 skip 5 10 30 and 60 seconds for each channel Connections Sensor connection is 4 lead 2 current and 2 voltage Response Curves Standard Curve 10 DT 500DI 8A also 8B and 8C DT 500DRC D DT 500DRC E1 CTI Curve C SoftCal works only with DT 470 471 diode sensors COMPUTER INTERFACE Type RS 232C Serial 3 Wire Refer to Table 4 1 for details MECHANICAL Ambient Temperature Range 18 28 C 64 82 F or 15 35 C 59 95 F with reduced accuracy Power Requirements 90 125 or 210 250 VAC 50 60 Hz 3 watts Dimensions 41 mm High x 106 mm Wide x 164 mm Deep 1 6 inches x 4 2 inches x 6 5 inches Weight 0 5 kilogram 1 1 Pounds NOTES 1 Product specifications are subject to change without notice 2 Electronic temperature accuracy of the system in a given temperature range is the sum of the specifications given for input and output Sensor calibration errors are not included Introduction 1 2 Lake Shore Model 201 208 User s Manual SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation service and repa
22. LOEONODOR 1 1 1 1 1 1 2 2 C 4 Curve Tables Lake Shore Model 201 208 User s Manual Table C 5 Curve 4 CTI Diode Voltage Temp Characteristics Temp PROM Temp PROM Temp PROM K Voltage BP K Voltage BP K Voltage Curve Tables C 5 Lake Shore Model 201 208 User s Manual Table C 6 Curve 5 DT 500DI 8C Voltage Temp Characteristics Temp PROM Temp PROM Temp PROM BP K Voltage BP K Voltage BP K Voltage C 6 Curve Tables Lake Shore Model 201 208 User s Manual Table C 7 Curve 6 DT 470 Voltage Temperature Characteristics Temp PROM BP K NNNPKNZI WN lt ROOO NOIR Curve Tables Voltage 1 69808 1 69674 1 69521 1 69355 1 69177 1 68987 1 68912 1 68574 1 68352 1 68121 1 67880 1 67632 1 67376 1 67114 1 66845 1 66571 1 66292 1 66009 1 65721 1 65430 1 65134 1 64833 1 64529 1 64219 1 64112 1 63587 1 63263 1 62602 1 61920 1 61220 1 60506 1 59782 1 59047 1 58303 1 57551 1 56792 1 56027 1 54097 1 52166 1 50272 1 48443 1 46700 1 44850 1 43488 1 42013 1 40615 1 39287 1 38021 BP Temp PROM K Voltage 1 36687 1 35647 1 34530 1 33453 1 32412 1 31403 1 30422 1 29340 1 28527 1 27607 1 26702 1 25810 1 24928 1 24053 1 23184 1 22314 1 21555 19645 17705 15558 13598 12463 11896 11517 11202 10945 10702 10465 10263 10060 1 09864 1 09675 1 09477 1 09309 1 09131 1 08955 1 08781 1 08436
23. MC mating connector Sensor Probe 6 inches 15 cm long by 1 8 inch 3 2 mm diameter stainless steel probe with 12 foot 3 7 meter cable with 4 stripped ends Sensor Probe 6 inches 15 cm long by 1 8 inch 3 2 mm diameter stainless steel probe with 12 foot 3 7 meter cable with 4 pin 201 MC mating connector Sensor Probe 12 foot 3 7 meter cable with DT 470 SD 13 sensor in CY mounting adapter stripped ends Temperature range limited to 325 K 52 C The diode sensor is epoxied Stycast into center of 0 564 inch 1 43 cm diameter by 0 20 inch 5 mm thick copper disk 30 AWG copper leads anchored to disk Mass excluding leads is 4 3 grams Sensor Probe 12 foot 3 7 meter cable with DT 470 SD 13 sensor in CY mounting adapter with 4 pin 201 MC mating connector Temperature range limited to 325 K 52 C The diode sensor is epoxied Stycast into center of 0 564 inch 1 43 cm diameter by 0 20 inch 5 mm thick copper disk 30 AWG copper leads anchored to disk Mass excluding leads is 4 3 grams Multi Connector Adapter Required with Model 208 when multiple probe cable assemblies and multiple Model 201 MC mating connectors are used Mounting Adapter for Rack Installation For installation in a panel EIA rack space See Figure 2 3 201 MC 4 pin Mating Connector for Model 201 and Model 2084 208 MC 36 pin D Style Connector for Model 208 6 2 Options amp Accessories Lake Shore Model 201 208 Us
24. RROR CODE TROUBLESHOOTING On power up the 201 208 does a check of the internal memory In the event that a problem exists an error message will be displayed on the instrument s front panel Er01 on the display indicates that there is a hardware problem in the instrument s memory In the case of Er01 or other failures use the following procedure CAUTION This procedure erases the calibration constants stored in the non volatile RAM If this procedure is used it will be necessary to recalibrate the instrument 1 With the power turned off press and hold the recessed CAL ENABLE button on the back panel While holding the CAL ENABLE button turn power to the instrument on 2 If the Model 201 208 now displays Er02 then proceed to the Calibration procedure in Paragraph 5 7 If the ErO1 is still displayed or if the Model 201 208 does not respond please contact the Instrument Service Department at Lake Shore Cryotronics at 614 891 2243 or the Dealer Representative from which the Model 201 208 was purchased Er02 on the display indicates that there is a soft error in the instrument s memory In the case of Er02 use the following procedure 1 Power up the unit and allow it to display Er02 2 Close DIP Switch 1 top of the switch pressed in Leave the switch closed for at least 5 seconds then open DIP switch 1 bottom of the switch pressed in 3 Verify the Model 201 208 display goes through a normal power up sequence a
25. ST NbTi Niobium titanium A superconductive alloy with a transition temperature typically near 9 K in zero magnetic field National Institute of Standards and Technology NIST Government agency located in Gaithersburg Maryland and Boulder Colorado that defines measurement standards in the United States parts per million ppm 4 x 10 is four parts per million Percent 96 The Model 241 can be configured to display the LHe level as a percentage Normally the low and high alarm setpoints are used to define 0 and 10096 Zero is used if the minimum alarm setpoint is undefined and the active probe length is used if the maximum alarm setpoint is undefined pounds per square inch psi A unit of pressure 1 psi 6 89473 kPa Variations include psi absolute psia measured relative to vacuum zero pressure where one atmosphere pressure equals 14 696 psia and psi gauge psig where gauge measured relative to atmospheric or some other reference pressure prefixes SI prefixes used throughout this manual are as follows Factor Prefix Symbol Factor Prefix Symbol 1077 yotta Y 107 deci d 10 zetta Z 10 centi c 1018 exa E 10 milli m 1015 peta P 106 micro T 1012 tera T 10 nano n 10 giga G 102 pico p 10 mega M 1075 femto f 10 kilo k 10 18 atto a 10 hecto h 10 zepto z 10 deka da 10724 yocto y Glossary of Terminology A 3 Lake Shore Model 201 208 User s Manual Resistance Per Unit Length O L Resistance of a unit le
26. T 1 A R INSTR AS W IF R 0 THEN GOTO 90 FOR Z 1 TO 500 NEXT Z LINE INPUT 1 B PRINT BS GOTO 11 100 CLOSE 1 OPEN UP THE COM PORT PRINT QUIT MESSAGE PRINT BLANK LINE GET COMMAND TO SEND LOOK FOR QUIT THEN QUIT ADDING CR AND LF SENDING COMMAND STRING SCAN CMD FOR W QUERRY IF NOT A QUERRY SKIP PRINT SHORT DELAY READ BACK 201 208 RESPONSE PRINT INSTRUMENT RESPONSE JUMP BACK TO THE BEGINNING CLOSE COM PORT END PROGRAM open the serial port print QUIT message print blank line get command to send check quit request adding CR and LF sending command string scan for W query if not query skip print short delay read back unit response print instrument response jump back to beginning close serial port end exit program 101 END 4 1 4 Sample Quick Basic 4 0 Program STARTUP OPEN COM1 300 0 7 1 RS FOR RANDOM AS 1 PRINT TYPE QUIT TO EXIT RESTART PRINT INPUT ENTER COMMAND AS IF AS QUIT THEN GOTO FINISH AS AS CHR 13 CHR 10 PRINT 1 A R INSTR A W IF R 0 THEN GOTO REJUMP FOR Z 1 TO 500 NEXT Z LINE INPUT 1 B PRINT BS REJUMP GOTO RESTART FINISH CLOSE 1 END 4 4 Remote Operation Lake Shore Model 201 208 User s Manual 4 2 SERIAL INTERFACE COMMANDS The following is a summary of the Serial Interface Commands recognized by the Model 201 208 Dig
27. THAT LAKE SHORE S LIABILITY WITH RESPECT TO THIS PRODUCT SHALL BE SET FORTH IN THIS WARRANTY AND INCIDENTAL OR CONSEQUENTIAL DAMAGES ARE EXPRESSLY EXCLUDED CERTIFICATION Lake Shore certifies that this product has been inspected and tested in accordance with its published specifications and that this product met its published specifications at the time of shipment The accuracy and calibration of this product at the time of shipment are traceable to the United States National Institute of Standards and Technology NIST formerly known as the National Bureau of Standards NBS or to a recognized natural standard TRADEMARK ACKNOWLEDGEMENT Manufacturers and sellers claim many designations as trademarks to distinguish their products Where those designations appear in this manual and Lake Shore was aware of a trademark claim the designations appear in initial capital letters with a or 9 symbol Apiezon is a trademark of Biddle Instruments Cryo Gloves is a trademark of Tempshield Duo Twist Quad Lead Quad Twist and SoftCal are trademarks of Lake Shore Cryotronics Inc Teflon is a trademark of DuPont De Nemours Copyright 1993 1995 1997 and 1999 by Lake Shore Cryotronics Inc All rights reserved No portion of this manual may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the express written p
28. alled before inserting the power cord and turning on the instrument To change voltage configuration refer to Chapter 5 NOTE Do not attach the shield to earth ground at the sensor end or noise may be introduced at the measurement end Table 2 1 Line Voltage and Fuse Rating Selection Select Range Fuse 115 90 125 VAC 0 2 A Slow Blow 230 210 250 VAC 0 1 A Slow Blow To protect operating personnel the National Electrical Manufacturer s Association NEMA recommends and some local codes require instrument panels and cabinets be grounded This instrument is equipped with a three conductor power cable which when plugged into an appropriate receptacle grounds the instrument Grounding and shielding of signal lines are major concerns when setting up any precision instrument or system The 201 208 has included ground isolation of the sensor excitation to allow 4 wire measurement of diode voltage and resistance Improper grounding of sensor leads and shields can defeat this feature Digital logic in the Model 201 208 is tied directly to earth ground for interface communication The low side of the heater output is directly connected to earth ground Shield sensor cables whenever possible Attach the shields to the shield pin provided in the connector Installation 2 4 2 4 1 Lake Shore Model 201 208 User s Manual SENSOR INSTALLATION RECOMMENDATIONS Abbreviated diode sensor installation recommendations for
29. below the high setpoint or rises above the low setpoint The alarm is unlatched when the LATCH Switch is in position O When unlatched the alarm will turn on when temperatures go beyond the setpoint range and automatically turn off when temperatures return to below the high setpoint or above the low setpoint Alarm Fix Function Model 208 Only When the FIX switch on the rear panel of Model 208 is OFF position 0 the relay will be continuously updated depending on the alarm setpoint and sensor temperature If the FIX switch is on position 1 the relay will be updated only when the channel 1 input is active SOFTCAL COMPENSATIONS SoftCal is an instrument configured software calibration procedure that is used to improve the system accuracy over a specified temperature range The SoftCal feature allows the user to reduce the error between a DT 470 diode and the Standard Curve 10 employed by the instrument In short SoftCal provides the means to generate inexpensive calibrations for DT 470 sensors used with Lake Shore temperature controllers and monitors SoftCal calibrations are made at three points liquid helium temperature 4 2 K liquid nitrogen temperature about 77 K and room temperature 305 K Resultant accuracy of the DT 470 SD 13 sensor will be 0 5 K 2 K to 30K 0 25 K 30 K to lt 60 K 0 15 K 60 K to lt 345 K 0 25 K 345 K to lt 375 K 1 0K 375 K to 475 K These accuracy values can generally be achieved for a
30. d on the rear panel is a RJ 11 modular socket designated J2 SERIAL I O for host computer connection Accessories 2001 RS 232C phone cord and 2002 RJ 11 to DB 25 adapter as well as a null modem adapter may be required to link the serial port on the host computer directly to the thermometer When programming a Model 201 208 from the serial interface the following considerations must be made e Commands must be typed in all CAPS e When the term free field is used it indicates that the decimal point is a floating entity and can be placed any appropriate place in the string of digits e term is used when examples are given and indicates where terminating characters should be placed by the user or where they appear on a returning character string from the unit e Leading zeros and zeros following a decimal point are not needed in a command string but they will be sent in response to a query e Temperature is to be entered to 0 1 degrees If entered with greater precision it will be truncated Also temperature is limited to 0 to 475 K e There should be no space between the commands and the variable being sent Remote Operation 4 3 4 1 10 11 12 20 21 30 40 45 46 50 60 70 90 Lake Shore Model 201 208 User s Manual 3 Sample Basica Program OPEN COM1 300 0 7 1 RS AS 1 PRINT TYPE QUIT TO EXIT PRINT INPUT ENTER COMMAND A IF AS QUIT THEN GOTO 100 AS AS CHR 13 CHR 10 PRIN
31. del 208 press the CHANNEL key to select additional channels for curve selection Then simply press the UNITS key to scroll through the curves After the new curve is selected turn the SET switch on the rear panel back off 0 The unit will now return to normal operation Table 2 2 Model 201 208 Temperature Curves Range K DT 500DI 8B DT 500DI 8A DT 500DRC D DT 500TDC E1 CTI Curve C DT 500DI 8C DT 470 Curve 10 RACK MOUNTING The Models 201 and 208 can be installed in a standard size 74 panel EIA rack space If you have ordered a 2090 rack mounting adapter use the following instructions for installation See Figure 2 3 1 Remove the front feet on the bottom of the unit and attach the lower rack piece using the threaded holes with two of the four screws provided 2 Locate the two mounting hole access covers on the top of the unit Attach the other rack Installation 2 9 Lake Shore Model 201 208 User s Manual 0 265 6 73 0 215 5 46 PME D S 2 50 63 5 Hole Sizes A 0 189 0 480 Diameter 4 Places B 0 169 0 429 Diameter 2 Places ii 1 50 38 10 Model 201 or 208 Front Panel m 1 25 31 75 35 58 4 18 106 17 gt C 201 2 3 eps Figure 2 3 Model 2090 Rack Mounting 2 10 Installation 2 8 2 9 Lake Shore Model 201 208 User s Manual INITIAL POWER UP SEQUENCE The following test sequence occurs at power up 1 All display segmen
32. e Assembly ese ee 6 4 6 2 Model 2002 RJ 11 to DB 25 Adapter ek ke 6 4 6 3 Model 2003 RJ 11 to DB 9 Adapter 6 5 LIST OF TABLES Table No Title Page 1 1 Model 201 208 SpecificatioNS i 1 3 2 1 Line Voltage and Fuse Rating Selection 2 2 2 2 Model 201 208 Temperature Curves eese 2 9 4 1 Serial Interface Specifications ee RR ee 4 1 B 1 Comparison of LHe to LN2 e B 1 C 1 Curve 0 DT 500DI 8B Voltage Temp Characteristics C 1 C 2 Curve 1 DT 500DI 8A Voltage Temp Characteristics C 2 C 3 Curve 2 DT 500DRC D Voltage Temp Characteristics C 3 C 4 Curve 3 DT 500DRC E1 Voltage Temp Characteristics C 4 C 5 Curve 4 CTI Diode Voltage Temp CharacteristicS C 5 C 6 Curve 5 DT 500DI 8C Voltage Temp Characteristics C 6 C 7 Curve 6 DT 470 Voltage Temp Characteristics C 7 Table of Contents Lake Shore Model 201 208 User s Manual This Page Intentionally Left Blank Table of Contents Lake Shore Model 201 208 User s Manual CHAPTER 1 INTRODUCTION 1 0 GENERAL This chapter provides an introduction to the Model 201 208 Digital Thermometer The Model 201 208 was designed and manufactured in the United States of America by Lake Shore Cryotronics A general description is provided in Paragraph 1 1 safety summary in Paragraph 1
33. e to be slow blow fuses CAUTION Replace fuse with the same type and rating as specified by the line voltage selected 5 Replace enclosure cover rear panel and all screws Line Voltage Configuration The rear panel three pronged line power connector permits the Model 201 208 to be connected to operate at either 110 or 220 VAC The configuration is indicated on rear panel in the Line Voltage Selection Block Use the following procedure to change the line voltage WARNING To prevent shock hazard turn off the instrument and disconnect it from AC line power Also ensure any attached test equipment is disconnected before changing the line voltage configuration Service Lake Shore Model 201 208 User s Manual Line Voltage Configuration Continued 1 Place the power ON OFF switch to OFF and disconnect the power cord from the unit Also disconnect all test equipment from unit 2 Remove all screws from rear panel Gently pull away rear panel and remove enclosure cover by sliding it to the back 3 Modify jumper configuration to desired line voltage as shown in Figure 5 3 4 Replace fuse to match new voltage requirements 5 Replace enclosure cover rear panel and all screws bd gt de TD bee T m 00 210 250 VAC SETTING P 201 5 3 bmp Figure 5 3 Line Voltage Jumper Configuration 5 7 Recalibration Lake Shore will calibrate and certify the thermometer to original factory specifications for a reasonable
34. elay latching is desired The switch ID parameter is O through 7 for the Model 208 Its the sum of 1 if the alarm set enable is set plus 2 if relay latching is desired plus 4 if the alarm fix is enabled The high or low parameter is H for a high alarm or L for a low alarm Scan Status Model 208 Only WY The following is returned for a Model 208 scan status current channel number channel which caused the alarm state channel 1 dwell time channel 2 dwell time channel 8 dwell time CR LF For a Model 208 only returns the instrument scan status scanning or holding the channel dwell information and the scan position The scan status parameter is H for holding of S for scanning The channel which caused the alarm state parameter will be 1 through 8 or a if the alarm is not active The channel dwell times will be returned in seconds If this command is sent with a Model 201 an N will be returned to signify no scanner Remote Operation 4 9 Lake Shore Model 201 208 User s Manual This Page Intentionally Left Blank Remote Operation 5 0 5 1 Lake Shore Model 201 208 User s Manual CHAPTER 5 SERVICE GENERAL This chapter contains service information for the Model 201 208 Digital Thermometer Model 201 rear panel connections are defined in Paragraph 5 1 Model 208 rear panel connections in Paragraph 5 2 error code troubleshooting in Paragraph 5 3 general maintenance in Paragraph 5 4 fuse replaceme
35. er s Manual 6 3 WIRES A list of wire available for the Model 201 208 are as follows P N 9001 005 Quad Twist Cryogenic Wire Two twisted pairs phosphor bronze wire 36 AWG 0 127 mm 0 005 inch diameter 9001 006 Duo Twist Cryogenic Wire Single twisted pair phosphor bronze wire 36 AWG 0 127 mm 0 005 inch diameter 9001 007 Quad Lead Cryogenic Wire Phosphor bronze wire flat 32 AWG 0 203 mm 0 008 inch diameter 8 9001 008 Quad Lead Cryogenic Wire Phosphor bronze wire flat 32 AWG 0 127 mm 0 005 inch diameter Any quality dual shield twisted pair wire for dewar to Model 201 208 connector 6 4 SENSORS A list of sensors available for the Model 201 208 are as follows sensora Sensor Description Series DT 420 The smallest silicon diode Temperature Sensor available For installation on flat surfaces Sensor incorporates the same type of silicon chip used in the Series DT 470 and DT 471 7 Silicon Diode Miniature Temperature Sensor Series DT 450 Same silicon chip used in the DT 470 configured for installation in recesses as small as 1 6 mm diameter by 3 2 mm deep Series DT 470 Silicon Diode Temperature Sensor Interchangeable repeatable accurate wide range customized for cryogenics Series DT 471 economical version of the DT 470 for applications where temperature measurements below 10 K are not required Options amp Accessories 6 3 Lake Shore Model 201 208 User s Man
36. ermission of Lake Shore Lake Shore Model 201 208 User s Manual Declaration of Conformity Lake Shore Cryotronics 575 McCorkle Blvd Inc Westerville OH 43082 8888 Hereby declare that the equipment specified conforms to the following Directives and Standards Application of Council Directives Standards to which Conformity is Declared Type of Equipment Model Number fne 89 336 EEC EN55022 A EN50082 1 Digital Thermometer 201 or 208 Me ay 7 777 Signature John M Swartz President Date Lake Shore Model 201 208 User s Manual Manual Addendum on EMC for the Model 201 or 208 Electromagnetic Compatibility EMC of electronic equipment is a growing concern worldwide Emissions of and immunity to electromagnetic interference is now part of most electronics design and manufacture To qualify for the CE mark the Model 201 or 208 meets the generic requirements of the European EMC directive 89 336 EEC as a Class A product Class A products radiate more RF than Class B products and must include the following warning WARNING This is a Class A Product In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures The instrument was tested under normal operating conditions with sensor and interface cables attached If the installation and operating instructions in the User s Manual are followed there should be no degradati
37. es Details of the Serial Interface are provided in Paragraph 4 1 Serial Interface Commands are described in Paragraph 4 2 SERIAL INTERFACE The Model 201 208 has a serial interface for RS 232C communications with a host computer RS 232C is an unbalanced single ended non terminated line used over short distances typically 10 feet or less The Model 201 208 serial interface complies with the electrical format of the RS 232C Interface Standard A standard 6 wire RJ 11 modular telephone jack is used for the serial interface connector Serial interface specifications are given in Table 4 1 Serial interface connections are defined in Paragraph 4 1 1 The serial interface hardware configuration and adapters are shown in Figures 4 1 and 4 2 The serial interface operation is outlined in Paragraph 4 1 2 Sample Basica and QuickBasic Programs are provided in Paragraphs 4 1 3 and 4 1 4 respectively Table 4 1 Serial Interface Specifications Transmission Three Wire Connector RJ 11 Modular Telephone Socket Timing Format Asynchronous Transmission Mode Half Duplex Baud Rate 300 Bits per Character 1 Start 7 Data 1 Parity 1 Stop Parity Type Odd Data Interface Levels Transmits Receives Using EIA Levels Terminator LF 0AH Serial Interface Connections A standard 6 wire RJ 11 modular telephone jack is used for the serial interface connector Lake Shore Model 2001 data type cables which maintains pin 1 pola
38. graph 3 4 alarm operation in Paragraph 3 5 SoftCal compensations in Paragraph 3 6 calibration in Paragraph 3 7 verifying SoftCal operation in Paragraph 3 8 and erasing SoftCal compensations in Paragraph 3 9 UNITS KEY The UNITS key selects the different units of measurement The thermometer reads in voltage or temperature kelvin Celsius or Fahrenheit Press the UNITS key to scroll through the various selections The UNITS key is also used to determine if the SoftCal feature is active Press and hold the UNITS key for 3 seconds If SoftCal is not active 0 0 0 will appear in the display CHANNEL KEY MODEL 208 ONLY This key scrolls through the eight possible sensor channels The Channel key is also used to determine if Scan mode is activated Press and hold 1 to 2 seconds to toggle the scan mode on or off A red light will glow in the upper left channel display if the scan mode is active SCAN MODE The thermometer can scan 8 channels or monitor 1 channel To enable scan mode press the CHANNEL key for more than 1 but less than 2 seconds If a light appears in the upper left of the channel display window then the thermometer is in SCAN mode If the light does not appear the thermometer is in single channel mode CHANNEL key is a toggle Repeat action to reverse mode Operation 3 1 Lake Shore Model 201 208 User s Manual 3 4 SETTING DWELL TIMES The time the thermometer pauses on each channel dwell can be set for
39. horting exists Also avoid putting stress on the device leads and allow for the thermal contractions that occur during cooling which could fracture a solder joint or lead if installed under tension at room temperature For temporary mounting in cold temperature applications a thin layer of Apiezon N Grease should be used between the sensor and sample to enhance the thermal contact under slight pressure The preferred method for mounting the DT 470 SD sensor is the Lake Shore CO Adapter CAUTION Lake Shore will not warranty replace any device damaged by a user designed clamp or damaged by solder mounting If semi permanent mountings are desired the use of Stycast epoxy can replace the use of Apiezon N Grease NOTE Do not apply Stycast epoxy over the DT 470 SD package Stress on the sensor can cause shifts in the readings In all cases the mounting of the sensor should be periodically inspected to verify that good thermal contact to the mounting surface is maintained Measurement Errors Due To AC Noise Poorly shielded leads or improperly grounded measurement Systems can introduce AC noise into the sensor leads For diode sensors the effect of the AC noise appears as a shift in the DC voltage measurement due to the non linear current voltage characteristics of the diode When this occurs the DC voltage measured will be too low and the corresponding temperature indication will be high The resulting measurement error can approach
40. ir of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Lake Shore Cryotronics Inc assumes no liability for the customer s failure to comply with these requirements Ground The Instrument To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground The instrument is equipped with a three conductor AC power cable The power cable must either be plugged into an approved three contact electrical outlet or used with a three contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet The power jack and mating plug of the power cable meet Underwriters Laboratories UL and International Electrotechnical Commission IEC safety standards Do Not Operate In An Explosive Atmosphere Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard Keep Away From Live Circuits Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified maintenance personnel Do not replace components with power cable connected To avoid injuries always disconnect power and discharge circuits before touching them Do Not Substitute Parts Or M
41. issing parts unless notified within 60 days of shipment REPACKAGING FOR SHIPMENT If itis necessary to return the Model 201 208 sensors or accessories for repair or replacement a Return Goods Authorization RGA number must be obtained from a factory representative before returning the instrument to our service department When returning an instrument for service the following information must be provided before Lake Shore can attempt any repair 1 Instrument model and serial number 2 Users name company address and phone number 3 Malfunction symptoms 4 Description of system 5 Returned Goods Authorization RGA number If possible the original packing material should be retained for reshipment If not available consult Lake Shore for shipping and packing instructions Installation 2 1 2 3 Lake Shore Model 201 208 User s Manual POWER AND GROUND REQUIREMENTS The Model 201 208 requires a power source of 90 125 or 210 250 VAC 50 or 60 Hz single phase 3 Watts A three prong detachable power cord for 120 VAC operation is included Connect to rear panel UL IEC ICEE standard plug The fuse rating is defined in Table 2 1 WARNING To prevent electrical fire or shock hazards do not expose this instrument to rain or excess moisture CAUTION Verify that the AC Line Voltage Selection Wheel located on the rear panel of the Model 201 208 is set to the available AC line voltage and that the proper fuse is inst
42. ital Thermometer Command Function EQ ue Sensor Units for Setpoint Hosen High Alarm Setpoint AE tetach Low Alarm Setpoint EE Reset Alarm AE ET Scan Dwell Time XQ Scanner Channel Selection XS asse Scan Enable EE Scan Disable WS Sensor Reading and Alarm Status Query WA uu Switch ID and Alarm Data Query WY Lus Scan and Dwell Query Model 208 Only An explanation of the command structure is shown below Brief Description of Function Command Name R Alarm Reset Syntax of user input input A Returned Nothing Information returned in response to the query Remarks Used to reset the alarm Explanation of returned data Remote Operation 4 5 Lake Shore Model 201 208 User s Manual Serial Interface Commands Continued FO Input Returned Remarks H Input Returned Remarks Example L Input Returned Remarks Example R Input Returned Remarks Set Temperature Display Sensor Units FOx Nothing Used to set the sensor units for the temperature display where x equals C for Celsius F for Fahrenheit K for kelvin or V for volts Select High Alarm Setpoint Value Hxxx x Nothing Used to select the high alarm setpoint value where xxx x equals the temperature setpoint Units will be as specified by command FO If the instrument is set for voltage units the alarm will default to kelvin units H300 term sets a high alarm setpoint of 300 degrees Select Low
43. ll sensors in the silicon diode family Two point only SoftCal calibrations are appropriate for DT 470 series Band 11 11A sensors and DT 471 diodes Operation Lake Shore Model 201 208 User s Manual 3 6 1 SoftCal Calibration The following is the Model 201 208 SoftCal calibration procedure 1 2 3 Operation Turn on thermometer 30 minutes prior to operation Place the SET switch in position 1 Hold the UNITS key until the display shows 0 kelvin or equivalent in C or F The key acts as a toggle If the display is rising release and press again Press the CAL ENABLE button on rear panel with a pen tip The display will read 52 F to indicate that the unit is ready to erase current SoftCal calibration Within 2 seconds press the UNITS key again The temperature display will change from 50 F to the current SoftCal setting Hold the UNITS key until the sensor temperature is displayed For example if SoftCal is being set for liquid helium the display should read 4 2 K If it is being set for ice point then the display should read 0 C Be certain the sensor is stabilized at calibration temperature Press the CAL ENABLE button again 50 F will again appear on display to indicate that the unit is ready to accept the calibration point Within 2 seconds press the UNITS key on the front panel if a new calibrations point is being entered If the UNITS key is not pressed within 2 seconds the display will return to
44. ls are defined below See Figure 5 2 J1 INPUTS Accepts 36 pin D style connector 208 MC and multi sensor adapters Adapter sits on top of thermometer and accepts up to 8 temperature sensors Adapter designed for either circular 4 pin 2084 or stripped wire 2081 sensors J2 SERIAL VO RJ 11 jack for serial remote communications to a host computer May require accessories 2001 RS 232C phone cord and 2002 RJ 11 to DB 25 adapter J3 ALARM Relay responds to alarm setpoints and can trigger another device Contact 1 is normally open contact 2 is normally closed FIX switch Switches alarm functions between monitoring all channels position 0 or monitoring channel 1 only position 1 LATCH switch When on position 1 turns alarm on but not off latched as indicated by temperature change When off position O turns alarm off or on unlatched SET switch Used in setting alarm setpoints and recalibration CAL ENABLE Calibration Enable pushbutton Used during A D Converter Calibration Refer to Paragraph 5 7 2 I ADJ Current Adjust trim potentiometer Used during Current Source Calibration Refer to Paragraph 5 7 1 J1 INPUTS J3 ALARM 1 COM 2 yee ROSS ol Je o iii FUSE 3AG SB 0 2 A 01A ENABLE 50 60 Hz Ac 90 125 v 210 250 v P 201 5 2 bmp Figure 5 2 Model 208 Rear Panel Connections Service 5 3 Lake Shore Model 201 208 User s Manual E
45. mission in which 128 numerals letters symbols and special control codes are represented by a 7 bit binary number as follows ole 5 cr O VON DU o m O w 5 AIR lt x lt eH o wlo v u 2 2 2 2 2 2 2 2 O O O O O OJOlO jolojojo lojojolo T Ojo OJO ojo Ojo F o O o O O O O oS5 o s 3 x s o alo alo c a lg o Ooj z zir c mOir o m mjioj oj mm o Mi JN lt x lt le a o N e wjy u A asphyxiant gas A gas which has little or no positive toxic effect but which can bring about unconsciousness and death by displacing air and thus depriving an organism of oxygen baud A unit of signaling speed equal to the number of discrete conditions or signal events per second or the reciprocal of the time of the shortest signal element in a character boiling point The temperature at which a substance in the liguid phase transforms to the gaseous phase commonly refers to the boiling point at sea level and standard atmospheric pressure Celsius C Scale A temperature scale that registers the freezing point of water as 0 C and the boiling point as 100 C under normal atmospheric pressure Celsius degrees are purely derived units calculated from the Kelvin Thermodynamic Scale Formerly known as centigrade See Temperature for conver
46. ms per liter EPA Hazard Categories Immediate Acute Health and Sudden Release of Pressure Hazards DOT Label Nonflammable Gas DOT Class Nonflammable Gas DOT Name Helium Refrigerated Liquid DOT ID No UN 1963 A 2 Glossary of Terminology Lake Shore Model 201 208 User s Manual liquid nitrogen LN2 Also used for low temperature and superconductivity research and for its refrigeration properties such as in freezing tissue cultures minimum purity 99 99896 O2 8 ppm max Boiling point at 1 atm 77 4 K Latent heat of vaporization 160 kilojoules per liter Liquid density 0 81 kilograms per liter EPA Hazard Categories Immediate Acute Health and Sudden Release of Pressure Hazards DOT Label Nonflammable Gas DOT Class Nonflammable Gas DOT Name Nitrogen Refrigerated Liquid DOT ID No UN 1977 LSCI Lake Shore Cryotronics Inc material safety data sheet MSDS OSHA Form 20 contains descriptive information on hazardous chemicals under OSHA s Hazard Communication Standard HCS These data sheets also provide precautionary information on the safe handling of the gas as well as emergency and first aid procedures MKSA System of Units A system in which the basic units are the meter kilogram and second and the ampere is a derived unit defined by assigning the magnitude 4n x 107 to the rationalized magnetic constant sometimes called the permeability of space NBS National Bureau of Standards Now referred to as NI
47. n the right and the negative lead cathode is on the left The Lake Shore DT 470 SD silicon diode sensor lead configuration is shown below For other sensors read the accompanying literature or consult the manufacturer to ensure positive identification of sensor leads Be sure the lead identification remains clear even after installation of the sensor It is also a good idea to record the serial number and location of the sensor DT 470 SD Diode Sensor Leads w Cathode anode On the DT 470 SD the base is the largest flat surface It is sapphire with gold metalization over a nickel buffer layer The base is electrically isolated from the sensing element and leads and all thermal contact to the sensor should be made through the base A thin braze joint around the sides of the SD package is electrically connected to the sensing element Contact to the sides with any electrically conductive material must be avoided When installing the sensor make sure there are no electrical shorts or current leakage paths between the leads or between the leads and ground If IMI 7031 varnish or epoxy is used it may soften varnish type lead insulations so that high resistance shunts appear between wires if sufficient time for curing is not allowed Installation 2 5 Lake Shore Model 201 208 User s Manual Sensor Mounting Continued 2 4 4 Teflon9 spaghetti tubing is useful for sliding over bare leads when the possibility of s
48. national system of units SI A universal coherent system of units in which the following seven units are considered basic meter kilogram second ampere kelvin mole and candela The International System of Units or Systeme International d Unit s SI was promulgated in 1960 by the Eleventh General Conference on Weights and Measures For definition spelling and protocols see Reference 3 for a short convenient guide IPTS 68 International Practical Temperature Scale of 1968 Also abbreviated as Teg ITS 90 International Temperature Scale of 1990 Also abbreviated as Too This scale was designed to bring into as close a coincidence with thermodynamic temperatures as the best estimates in 1989 allowed Kelvin K The unit of temperature on the Kelvin Scale It is one of the base units of SI The word degree and its symbol are omitted from this unit See Temperature Scale for conversions Kelvin Scale The Kelvin Thermodynamic Temperature Scale is the basis for all international scales including the ITS 90 It is fixed at two points the absolute zero of temperature 0 K and the triple point of water 273 16 K the equilibrium temperature that pure water reaches in the presence of ice and its own vapor liquid helium LHe Used for low temperature and superconductivity research minimum purity 99 998926 Boiling point at 1 atm 4 2 K Latent heat of vaporization 2 6 kilojoules per liter Liquid density 0 125 kilogra
49. nd then displays 499 9 K 4 The input s of the Model 201 208 must now be recalibrated per in procedure in Paragraph 5 7 before the unit can be used OL means overload indicating the voltage input is too high This can be caused by an open sensor or diode sensor wired backwards Service 5 3 5 4 5 5 5 6 Lake Shore Model 201 208 User s Manual GENERAL MAINTENANCE Clean the 201 208 periodically to remove dust grease and other contaminants Use the following procedure NOTE Do not use aromatic hydrocarbons or chlorinated solvents to clean the Model 201 208 They may react with the silk screen printing on the back panel 1 Clean the front and back panels and case with a soft cloth dampened with a mild detergent and water solution FUSE REPLACEMENT Use the following procedure to check and or replace the fuse WARNING To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before replacing the fuse 1 Turn POWER switch off and disconnect the power cord from the unit Also disconnect all test equipment from unit 2 Remove all screws from rear panel Gently pull away rear panel and remove enclosure cover by sliding it to the back 3 Remove fuse with a fuse puller The fuse is located behind the transformer as shown in Figure 5 3 4 Replace with a 0 2 ampere fuse for 110 V 115 VAC operation or a 0 1 ampere fuse for 220 V 230 VAC operation Both values ar
50. ngth of superconductive wire at a temperature where the is not superconducting The Model 241 will work with sensors with an effective resistance range of 4 to 7 Q cm 1 6 to 2 8 Q in to a maximum resistance of 3500 RS 232C Bi directional computer serial interface standard defined by the Electronic Industries Association EIA The interface is single ended and non addressable Sample Period Time between level readings On the Model 241 the time can be user defined from 0 to 19 hours 59 minutes or turned off setpoint The value selected to be maintained by an automatic controller serial interface A computer interface where information is transferred one bit at a time rather than one byte character at a time as in a parallel interface RS 232C is the most common serial interface SI Syst me International d Unit s See International System of Units temperature scales See Kelvin Scale Celsius Scale and ITS 90 Proper metric usage requires that only kelvin and degrees Celsius be used However since degrees Fahrenheit is in such common use all three scales are delineated as follows Boiling point of water 373 15 K 100 C 212 F Triple point of water 273 16 K Freezing point of water 273 15 K 0 C 32 F Absolute zero OK 273 15 C 459 67 F kelvin Celsius Fahrenheit To convert kelvin to Celsius subtract 273 15 To convert Celsius to Fahrenheit multiply C by 1 8 then add 32 or F 1 8 x C 32 To con
51. nt in Paragraph 5 5 line voltage selection in Paragraph 5 6 calibration in Paragraph 5 7 and serial interface cable and adapters in Paragraph 5 8 MODEL 201 REAR PANEL CONNECTIONS Model 201 rear panel connections and controls are defined below See Figure 5 1 J1 INPUT 1 Accepts a circular 4 pin connector temperature sensor 201 MC J2 SERIAL I O RJ 11 jack for serial remote communications to a host computer May require accessories 2001 RJ 11 phone cord and 2002 RJ 11 to DB 25 adapter J3 ALARM Relay responds to alarm setpoints and can trigger another device Contact 1 is normally open contact 2 is normally closed SWitch Not used LATCH switch When on position 1 turns alarm on but not off latched as indicated by temperature change When off position O turns alarm off or on unlatched SET switch Used in setting alarm setpoints and recalibration J1 INPUT 1 J3 ALARM 1 COM 2 o 0 1 rSET P 201 5 1 bmp Figure 5 1 Model 201 Rear Panel Connections Service 5 1 Lake Shore Model 201 208 User s Manual Model 201 Rear Panel Connections Continued 5 2 CAL ENABLE Calibration Enable pushbutton Used during A D Converter Calibration Refer to Paragraph 5 7 2 I ADJ Current Adjust trim potentiometer Used during Current Source Calibration Refer to Paragraph 5 7 1 MODEL 208 REAR PANEL CONNECTIONS Model 208 rear panel connections and contro
52. odify Instrument Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to an authorized Lake Shore Cryotronics Inc representative for service and repair to ensure that safety features are maintained Introduction Lake Shore Model 201 208 User s Manual 1 3 SAFETY SYMBOLS Introduction Product will be marked with this symbol in order to protect against damage to the instrument Indicates dangerous voltage terminals fed by voltage over 1000 volts must be so marked Protective conductor terminal For protection against electrical shock in case of a fault Used with field wiring terminals to indicate the terminal which must be connected to ground before operating equipment Low noise or noiseless clean ground earth terminal Used for a signal common as well as providing protection against electrical shock in case of a fault A terminal marked with this symbol must be connected to ground in the manner described in the installation operating manual and before operating equipment Frame or chassis terminal A connection to the frame chassis of the equipment which normally includes all exposed metal structures Alternating current power line Direct current power line Alternating or direct current power line 1 5 Lake Shore Model 201 208 User s Manual This Page Intentionally Left Blank
53. of Customers including university and national laboratories aerospace and other industries as well as many of the premier companies around the world
54. on in EMC performance Pay special attention to instrument cabling Improperly installed cabling may defeat even the best EMC protection For the best performance from any precision instrument follow the grounding and shielding instructions in the User s Manual In addition the installer of the Model 201 or 208 should consider the following Leave no unused or unterminated cables attached to the instrument Make cable runs as short and direct as possible Do not tightly bundle cables that carry different types of signals Add the clamp on ferrite filter part number 109 053 included with the connector kit to the serial interface cable near the instrument rear panel when that interface is used Lake Shore Model 201 208 User s Manual TABLE OF CONTENTS Chapter Paragraph Title Page 1 INTRODUCTION 2 iaia 1 1 1 0 Generali wens RE m Patet ES Oe ee e SLANG AA 1 1 1 1 System Description i 1 1 1 2 Safety SUMMAFY i 1 4 1 3 Safety Symbols ER RE derent ende 1 5 2 INSTALLATION nnne RE Ee RR RR EER RR Ee ee 2 1 2 0 EE ORE EE W er intera is 2 1 2 1 Inspection and UnpacKking iese ee ee RA 2 1 2 2 Repackaging For Shipment sees ee ee ee ee ee 2 1 2 3 Power and Ground Requirements 2 2 2 4 Sensor Installation Recommendations 2 3 2 4 1 Two Lead Vs Four Lead Measurements 2 3 2 4 1 1 Fou
55. r Lead Measurements nee 2 4 2 4 1 2 Two Lead Measurements iese ee ee ee 2 4 2 4 2 Connecting Leads to the Sensor 2 4 2 4 3 Sensor Mounting eee aa aaa aaaaaansanaaaa 2 5 2 4 4 Measurement Errors Due To AC Noise 2 6 2 5 Sensor Input Connections seeeeeee 2 7 2 6 Sensor Curve Definition ee ee RA ee ee 2 9 2 7 Rack MOUNINO EE EA ON EE HR N 2 9 2 8 Initial Power Up Sequence 2 11 2 9 Power Up EITOIS rincon e eer ee 2 11 3 OPERATION ciiin ii 3 1 3 0 General EE acz dea ete ed oo iti 3 1 3 1 Units Key serale 3 1 3 2 Channel Key Model 208 Only ee 3 1 3 3 Scan Mode oie eee LR 3 1 3 4 Setting Dwell Times Re ee RA ee ee ee 3 2 3 5 Alarm Operation ese ee Re Re ee e 3 3 3 5 1 Alarm Setpoint Ge ESE ie ieee 3 3 3 5 2 Latched and Unlatched Alarms esse ese ee ee 3 4 3 5 3 Alarm Fix Function Model 208 Only 3 4 3 6 SoftCal Compensations ii 3 4 3 6 1 SoftCal Calibration aaa aaa aaa cccca 3 5 3 6 2 Verifying SoftCal Operation ee ke 3 6 3 6 3 Erasing SoftCal Compensations 3 6 Table of Contents Lake Shore Model 201 208 User s Manual TABLE OF CONTENTS Continued Chapter Paragraph Title Page 4 REMOTE OPERATION
56. reas with water that is near body temperature The two most important safety aspects to consider when handling LHe and LN are adequate ventilation and eye and skin protection Although helium and nitrogen gases are non toxic they are dangerous in that they replace the air in a normal breathing atmosphere Liquid products are of an even greater threat since a small amount of liquid evaporates to create a large amount of gas Therefore it is imperative that cryogenic dewars be stored and operated in open and well ventilated areas Persons transferring LHe and LN2 should make every effort to protect eyes and skin from accidental contact with liquid or the cold gas issuing from it Protect your eyes with full face shield or chemical splash goggles Safety glasses even with side shields are not adequate Always wear special cryogenic gloves Tempshield Cryo Gloves or equivalent when handling anything that is or may have been in contact with the liquid or cold gas or with cold pipes or equipment Long sleeve shirts and cuffless trousers that are of sufficient length to prevent liquid from entering the shoes are recommended B5 0 RECOMMENDED FIRST AID Every site that stores and uses LHe and LN should have an appropriate Material Safety Data Sheet MSDS present The MSDS may be obtained from the manufacturer distributor The MSDS will specify the symptoms of overexposure and the first aid to be used A typical summary of these instructions i
57. resistance per foot is preferred to minimize this heat flow Consequently a voltage drop within the leads can be present In a four lead measurement scheme the current is confined to one pair of current leads with the sensor voltage measured using the remaining lead pair which is not carrying current Installation 2 3 2 4 1 1 2 4 1 2 2 4 2 Lake Shore Model 201 208 User s Manual Four Lead Measurements All sensors including both two lead and four lead devices can be measured in a four lead configuration to eliminate the effects of lead resistance The exact point at which the connecting leads are soldered to the two lead sensor normally results in a negligible temperature uncertainty l V Four Lead Diode V l Two Lead Measurements Sometimes system constraints dictate the use of two lead measurements Connect the positive terminals V and I together and the negative terminals V and I together at the instrument then run two leads to the sensor EE WE Two Lead Measurements Some loss in accuracy can be expected since the voltage measured at the voltmeter becomes the sum of the sensor voltage and the voltage drop across the connecting leads The exact measurement error will depend on sensor sensitivity and variations resulting from changing temperature For example a 10 Q lead resistance will result in a 0 1 mV voltage error The resultant temperature error at liquid helium temperature is only
58. resistor voltage to settle Press CAL ENABLE button then within 2 seconds press UNITS key The display window will show C A L for approximately 15 seconds Repeat procedure with 25 kO resistor For Model 208 repeat procedure for other 7 channels See Figure 2 2 for pin assignments Service Lake Shore Model 201 208 User s Manual 5 8 SERIAL INTERFACE CABLE AND ADAPTERS To aid in Serial Interface troubleshooting wiring information for the cable assembly and the two mating adapters are provided in Figures 5 5 thru 5 7 YELLOW GREEN RED BLACK C 201 5 5 eps TxD Gnd Gnd RxD 123456 9G ve cl Figure 5 5 Model 2001 RJ 11 Cable Assembly Wiring Details DB 25 CONNECTOR NOT USED RJ 11 RECEPTACLE C 201 5 6 eps Figure 5 6 Model 2002 RJ 11 to DB 25 Adapter Wiring Details Service 5 7 Lake Shore Model 201 208 User s Manual DE 9 CONNECTOR NOT USED RJ 11 RECEPTACLE C 201 5 7 eps Figure 5 7 Model 2003 RJ 11 to DE 9 Adapter Wiring Details Service Lake Shore Model 201 208 User s Manual CHAPTER 6 OPTIONS AND ACCESSORIES 6 0 GENERAL This chapter provides lists of models options accessories sensors wires and special equipment available for the Model 201 208 6 1 MODELS A list of the available Digital Thermometer models are as follows Mods DescrptionofMode Single Channel Digital Thermometer configured for 90 140 VAC Includes one Model 201 M
59. rity are used to simplify interconnection Lake Shore offers the Model 2002 RJ 11 to DB 25 adapter and Model 2003 RJ 11 to DB 9 adapter for connecting to the host computer See Figure 4 2 Remote Operation 4 1 Lake Shore Model 201 208 User s Manual SERIAL VO DUI T2327 C 201 4 1 eps PN DESCRIPTION Serial In RxD Serial In RxD Serial Ground Serial Ground Serial Out TxD Serial Out TxD Figure 4 1 Serial VO RJ 11 Connector Pin Definitions SERIAL VO LSCI Model 2002 RJ 11 to DB 25 Adapter Rear of Model 201 208 To customer supplied computer with DB 25 Serial Interface Connector configured as DCE If Adapter is required to exchange Transmit and Receive lines Use whichever adapter that matches your computer serial interface connector LSCI Model 2001 RJ 11 LSCI Model 2003 RJ 11 Cable Assembly to DE 9 Adapter To customer supplied computer with DE 9 Serial Interface Connector configured as DTE If the interface is DCE a Null Modem the interface is DTE a Null Modem Adapter is required to exchange Transmit and Receive lines C 201 4 2 eps Figure 4 2 Serial Interface Connections 4 2 Remote Operation Lake Shore Model 201 208 User s Manual Serial Interface Operation All thermometer functions except setting SoftCal compensations can be controlled remotely from a host computer equipped with communications software and modem Locate
60. s w cm K Latent Heat of Vaporization Btu liter Liquid Density pounds liter B3 0 HANDLING CRYOGENIC STORAGE DEWARS All cryogenic containers dewars must be operated in accordance with the manufacturer s instructions Safety instructions will also be posted on the side of each dewar Cryogenic dewars must be kept in a well ventilated place where they are protected from the weather and away from any sources of heat B4 0 LIQUID HELIUM AND NITROGEN SAFETY PRECAUTIONS Transferring LHe and LN should be in accordance with the manufacturer supplier s instructions During the transfer all safety precautions written on the storage dewar and recommended by the manufacturer must be followed WARNING Liquid helium and liquid nitrogen are potential asphyxiants and can cause rapid suffocation without warning Store and use in area with adequate ventilation DO NOT vent container in confined spaces DO NOT enter confined spaces where gas may be present unless area has been well ventilated If inhaled remove to fresh air If not breathing give artificial respiration If breathing is difficult give oxygen Get medical help Handling of LHe amp LN B 1 Lake Shore Model 201 208 User s Manual WARNING Liquid helium and liquid nitrogen can cause severe frostbite to the eyes or skin DO NOT touch frosted pipes or valves In case of frostbite consult a physician at once If a physician is not readily available warm the affected a
61. s provided as follows If symptoms of asphyxia such as headache drowsiness dizziness excitation excess salivation vomiting or unconsciousness are observed remove the victim to fresh air If breathing is difficult give oxygen If breathing has stopped give artificial respiration Call a physician immediately If exposure to cryogenic liquids or cold gases occurs restore tissue to normal body temperature 98 6 F as rapidly as possible then protect the injured tissue from further damage and infection Call a physician immediately Rapid warming of the affected parts is best achieved by bathing it in warm water The water temperature should not exceed 105 F 40 C and under no circumstances should the frozen part be rubbed either before or after rewarming If the eyes are involved flush them thoroughly with warm water for at least 15 minutes In case of massive exposure remove clothing while showering with warm water The patient should not drink alcohol or smoke Keep warm and rest Call a physician immediately B 2 Handling of LHe amp LN Lake Shore Model 201 208 User s Manual APPENDIX C CURVE TABLES C1 0 GENERAL The following curve tables are applicable to the Model 201 208 Digital Thermometer Curve 0 DT 500DI 8B is detailed in Table C 1 Curve 1 DT 500DI 8A in Table C 2 Curve 2 DT 500DRC D in Table C 3 Curve 3 DT 500DRC E1 in Table C 4 Curve 4 CTI Curve C in Table C 5 Curve 5 DT 500DI 8C in Table
62. ser s Manual General Description Continued The Model 201 and 208 provide a usable temperature range not attainable in many other digital thermometers Combined with Lake Shore DT 470 and DT 471 Series silicon diode temperature sensors the digital thermometers provide repeatable accurate measurements from nearly 0 Kelvin to well above room temperature All Lake Shore DT 470 and DT 471 Series Sensors follow the same temperature response curve Curve 10 Five bands of tracking accuracy are offered so that sensor selection can be made with both technical and economic considerations for a given application The eight channel Model 208 features a user programmable scan dwell operation mode with dwell times of O skip 5 10 30 or 60 seconds OPOR G amp Lake Shore Cryotronics 201 THERMOMETER P 201 1 1 bmp Figure 1 1 Model 201 Front Panel EHBHB C CHANNEL X ON Lake Shore Cryotronics JL OFF 208 THERMOMETER P 201 1 2 bmp Figure 1 2 Model 208 Front Panel 1 2 Introduction Lake Shore Model 201 208 User s Manual Table 1 1 Model 201 208 Specifications Display Four digit LED display Resolution 0 1 for values gt 100 or lt 100 0 01 for values between 100 lt T lt 100 Temperature Range 1 4 K to 475 K without probe 23 K to 473 K with probe System Accuracy To within 0 1K in the range of 177 K to 313 K To 0 2 K or better over range of 30 K to 373 K Above 373 K accuracy will be 41 0
63. sions Glossary of Terminology A 1 Lake Shore Model 201 208 User s Manual cgs system of units A system in which the basic units are the centimeter gram and second cryogen See cryogenic fluid cryogenic Refers to the field of low temperatures usually 130 F or below as defined by 173 300 f of Title 49 of the Code of Federal Regulations cryogenic fluid A liquid that boils at temperatures of less than about 110 K at atmospheric pressure such as hydrogen helium nitrogen oxygen air or methane Also known as cryogen cryostat An apparatus used to provide low temperature environments in which operations may be carried out under controlled conditions degree An incremental value in the temperature scale i e there are 100 degrees between the ice point and the boiling point of water in the Celsius scale and 180 degrees between the same two points in the Fahrenheit scale electrostatic discharge ESD A transfer of electrostatic charge between bodies at different electrostatic potentials caused by direct contact or induced by an electrostatic field excitation Either an AC or DC input to a sensor used to produce an output signal Common excitations include constant current constant voltage or constant power Fahrenheit F Scale A temperature scale that registers the freezing point of water as 32 F and the boiling point as 212 F under normal atmospheric pressure See Temperature for conversions inter
64. ts are lighted 2 The unit displays 20 1 or 2 0 8 3 The instrument then begins normal operation The Units selected will flash Model 208s also indicate the selected channel POWER UP ERRORS On power up the 201 208 does a check of the internal memory In the event that a problem exists an error message will be displayed on the instrument s front panel ERO on the display indicates that there is a hardware problem in the instrument s memory This error is not correctable by the user and the factory should be consulted ERO on the display indicates that there is a soft error in the instrument s memory This error can be corrected by closing dip switch 1 on the rear panel for at least 5 seconds Then put the switch in the open position You must follow the calibration procedure described in Paragraph 5 3 after an error 2 has been reset QL means overload indicating the voltage input is too high This can be caused by an open sensor or diode sensor wired backwards Installation 2 11 Lake Shore Model 201 208 User s Manual This Page Intentionally Left Blank Installation 3 0 31 8 2 3 3 Lake Shore Model 201 208 User s Manual CHAPTER 3 OPERATION GENERAL This chapter describes operation of the Model 201 208 Digital Thermometer Units key operation is provided in Paragraph 3 1 Channel key Model 208 only in Paragraph 3 2 scan mode in Paragraph 3 3 setting dwell times in Para
65. ual Cable Length 4 3 meters 14 feet C 201 6 1 eps Figure 6 1 Model 2001 RJ 11 Cable Assembly o o K o9 g o 2 g o 3 o 2 3 8 N 5 _ o 2 2 o o 2 g o 3 o X o og 43 mm 1 69 inches 15 8 mm 0 63 inches C 201 6 2 eps Figure 6 2 Model 2002 RJ 11 to DB 25 Adapter O 000001 90000 O TN 15 9 mm 0 6 inches C 201 6 3 eps Figure 6 3 Model 2003 RJ 11 to DE 9 Adapter 6 4 Options amp Accessories Lake Shore Model 201 208 User s Manual APPENDIX A GLOSSARY OF TERMINOLOGY absolute zero The temperature of 273 15 C or 459 67 F or 0 K thought to be the temperature at which molecular motion vanishes and a body would have no heat energy active length Defined as the electrically active length of the helium level sensor As opposed to actual physical length which due to sensor mounting provisions will be somewhat larger alarm setpoints Low and high alarm setpoints are defined by the user The low alarm is always active and will sound whenever the LHe level drops below the setpoint The high alarm is only active in Continuous Mode used during filling and will sound when the LHe level rises above the setpoint ambient temperature The temperature of the surrounding medium such as gas or liquid which comes into contact with the apparatus American Standard Code for Information Exchange ACSII A standard code used in data trans
66. use of Duo Twist Cryogenic Wire which features phosphor bronze wire 32 or 36 AWG twisted at 3 15 twists per centimeter 8 twists per inch Duo Twist wire is available from Lake Shore Refer to the Lake Shore Product Catalog or contact Lake Shore for further information 2 5 SENSOR INPUT CONNECTIONS The Model 201 has one rear panel 4 pin sensor input connector designated J1 INPUT 1 The connector pins numbered 1 thru 4 are shown in Figure 2 1 J1 INPUT 1 4 oo 1 o O 3 2 C 201 2 1 eps Terminal Description 4 Current Out 1 Current Out 2 Voltage Sense 3 Voltage Sense Case Shield Figure 2 1 Model 201 Sensor Connector J1 Details Installation 2 7 Sensor Input Connections Continued Lake Shore Model 201 208 User s Manual The Model 208 has a 36 pin Miniature D style connector designated J1 INPUTS for inputs 1 thru 8 A Model 208 D connector is included to solder interfacing connections to J1 The pin configuration of the Model 208 D is shown in Figure 2 2 2 4 6 8 10 12 14 16 18 13579 11 13 15 17 O O U OU OUOU CC O O EL CIC C N OOOOOOOOO OOOOOOOO M 20 22 24 26 28 30 32 34 36 19 21 23 25 27 29 31 33 35 C 201 2 2 eps Terminal Description Input Terminal Description Input 1 V 1 19 l 1 2 V 1 20 l 1 3 V 2 21 2 4 V 2 22 l 2 5 V 3 23 3 6 V 3 24 l 3 7 V 4 2
67. vert Fahrenheit to Celsius subtract 32 from F then divide by 1 8 or C F 32 1 8 References 1 Sybil P Parker Editor Dictionary of Scientific and Technical Terms Third Edition New York McGraw Hill 1969 IBSN 0 395 20360 0 2 Christopher J Booth Editor The New IEEE Standard Dictionary of Electrical and Electronic Terms IEEE Std 100 1992 Fifth Edition New York Institute of Electrical and Electronics Engineers 1993 IBSN 1 55937 240 0 Definitions printed with permission of the IEEE 3 Nelson Robert A Guide For Metric Practice Page BG7 8 Physics Today Eleventh Annual Buyer s Guide August 1994 ISSN 0031 9228 coden PHTOAD A 4 Glossary of Terminology Lake Shore Model 201 208 User s Manual APPENDIX B HANDLING OF LIQUID HELIUM AND NITROGEN B1 0 GENERAL Liquid Helium LHe and liquid nitrogen LN2 are often used in association with the Model 201 208 Digital Thermometer Although not explosive the following are safety considerations in the handling of LHe and LN B2 0 PROPERTIES LHe and LN are colorless odorless and tasteless gases Gaseous nitrogen makes up about 78 of the Earth s atmosphere while helium comprises only about 5 ppm Most helium is recovered from natural gas deposits Once collected and isolated gases will liquefy when properly cooled Refer to Table B 1 Table B 1 Comparison of Liquid Helium to Liquid Nitrogen Boiling Point 1 atm in K Thermal Conductivity Ga

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