Home

Model 320 - Lake Shore Cryotronics, Inc.

1. Liquid Nitrogen LN2 Also used for low temperature and superconductivity research and for its refrigeration properties such as in freezing tissue cultures minimum purity 99 998 O2 8 ppm max Boiling point 1 atm 77 K Latent heat of vaporization 152 Btu liter Liquid density 0 78 Ibs liter EPA Hazard Categories Immediate Acute DOT Label Nonflammable Gas Health and Sudden Release of Pressure Hazards DOT Class Nonflammable Gas DOT Name Nitrogen Refrigerated Liquid DOT ID No UN 1977 A 2 Glossary _ Lake Shore Model 320 Autotuning Temperature Controller User s Manual Materlal 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 4x x 107 to the rationalized magnetic constant sometimes called the permeability of space Normally Closed Abbreviation N C A term used for switches and relay contacts Provides a normally closed circuit when actuator is in the free unenergized position Normally Open Abbreviation N O A term used for switches and relay contacts Provides a normally open circuit when actuator is in the free
2. 0 9948 2 8428 4 7704 7 1149 9 5570 12 4425 13 5573 15 0010 15 0000 6 4582 6 4551 6 4486 6 4376 6 4205 6 3951 6 3529 6 2913 6 2149 6 1022 6 0099 5 8634 5 6989 5 5156 5 3166 4 9881 4 6240 4 2267 3 7994 3 1866 2 5259 1 6463 0 5186 0 8688 3 1298 4 9999 7 6164 9 6125 12 2790 15 0010 Lake Shore Model 320 Autotuning Temperature Controller Users Manual Copper vs Constantan 15 0000 6 2584 6 2523 6 2401 6 2184 6 1888 6 1404 6 0615 5 9535 5 7995 5 5753 5 3204 5 0337 4 7194 4 3767 3 8781 3 3278 2 7342 1 9295 1 0586 0 1254 1 0616 2 3247 3 6639 5 3095 7 0419 9 1113 11 2758 13 8053 14 9685 15 0010 Lake Shore Model 320 Autotuning Temperature Controller User s Manual This Page Intentionally Left Blank Curve Tables Lake Shore Model 320 Autotuning Temperature Controller User s Manual APPENDIX D APPLICATION NOTES D1 0 GENERAL The following Lake Shore Applications Notes are included with this manual 1 Fundamentals For Usage Of Cryogenic Temperature Controllers 2 DT 470 Series Temperature Sensors Installation and Operation 3 Measurement System Induced Errors in Diode Thermometry Application Notes D 1 Lake Shore Model 320 Autotuning Temperature Controlle
3. Lake Shore Model 320 Autotuning Temperature Controller User s Manual Table C 2 Thermocouple Curves Chromel vs Au 0 03 at Fe Chromel vs Au 0 07 at Fe Temp K V mvV Temp K V mv Breakpoint Number 1 15 0000 15 0000 2 4 6676 5 2982 3 4 6067 5 2815 4 4 5259 5 2594 5 4 4571 5 2285 6 4 3703 5 1742 7 4 2869 5 0315 8 3 9928 4 9126 9 3 8830 4 5494 3 8126 4 3810 3 7411 4 1733 3 5948 3 9952 3 4436 3 8132 3 2026 3 6270 3 0374 3 4370 2 8689 3 2435 2 6957 2 9477 2 5184 2 6452 2 2468 2 3372 2 0615 2 0242 1 8725 1 6004 1 5839 1 1693 1 2905 0 6232 0 9912 0 0705 0 6847 0 5986 0 1670 0 7158 0 0378 0 8431 0 2387 0 9944 0 6350 1 1940 1 0387 1 4841 15 0010 15 0010 Curve Tables Breakpoint Number OON OO WD Curve Tables Table C 3 Thermocouple Curves Temp K E Vrc mvV Temp K K V mV 15 0000 9 8355 9 8298 9 8182 9 7956 9 7570 9 7013 9 6204 9 5071 9 3366 9 1345 8 9030 8 6475 8 3673 7 9064 7 3943 6 8386 6 2400 5 3831 4 4564 3 4702 2 1605 0 7666
4. V Line voltage is present inside the box Only gualified personnel should proceed beyond this point 1 Locate zero adjustment R6 span adjustment R7 and offset adjustment R8 on top rear of instrument Side of Unit R6 R7 R8 V 2 le le lo Top View of Model 320 Adjustment Potentiometers Rear of Unit Attach voltage standard as shown above Set voltage standard to zero output Plug in instrument and place Power switch to on in position Turn off heater Select display units to be in sensor units millivolts Select Curve 6 with compensation off Allow unit to warm up for 1 hour Adjust R6 to obtain a display reading of 0 000 0 001 mV Change voltage standard output to 14 000 millivolts Adjust R7 until display reads 14 000 mV 10 Change voltage standard to 14 000 millivolts display should read 14 000 0 002 mV If not check zero input and readjust R6 11 Place Power switch to off out position 12 Disconnect test connector D ONO PWN When a new or different thermocouple is attached to the instrument it is necessary to adjust the offset to compensate for discrepancies in thermocouple material leads and connections An offset adjustment trimpot is provided to allow offset calibration of the thermocouple The steps below outline the procedure 13 Place thermocouple in a reference bath of known temperature liquid nitrogen ice etc Allow system to stabilize to reference temperature 14 On f
5. Query Only and XXX separate Command and Query Display Commands Command Function IDN Identification Query CUNI Set Control Units CUNI Control Units Query CDAT Control Sensor Data Query Channel Commands Command Function ACUR Set curve for A ACUR Curve A Query ACOMP Set A Compensation ACOMP A Compensation Query ATYPE A Input Type Query Control Process Commands Command Function TUNE Tune Status TUNE Tune Query GAIN Set Gain GAIN Gain Query RSET Set Reset RSET Reset Query RATE Set Rate RATE Rate Query RANG Set Range RANG Range Query HEAT Heater Query SETP Set Setpoint SETP Setpoint Query Curve Commands Command Function CUID Curve Identification Query ECUR Edit Curve KCUR Curve Deletion CURV11 Enter User Curve CURV Curve Number Information Query 5 4 Remote Operation _ Lake Shore Model 320 Autotuning Temperature Controller User s Manual 5 2 1 Display Commands This paragraph provides a detailed description of each Display Command The display commands allow the interface to act as a virtual display Display data as well as format can be transferred An explanation of the command structure is shown below Syntax of what user must input Information returned in response Explanation and definition of returned data IDN input Returned Remarks Example CUNI input Returned Remarks Example Command Name Brief Description of Function Control
6. RDG Temperature Accuracy 0 1 K at 4 2 K 0 2 K at 30 K 0 4 K at 4 2 K with Calibrated Sensor 0 3 K at 77 K 0 2 Kat 77 K 0 2 K at 300 K and Precision Option 0 2 K at 300 K 0 3 K at 300 K 10 2 Kat475K 0 6 K at 800 K Measurement Temp Coefficient Sensor Units RDG C 0 01 0 01 0 018 Temperature 5 mK C at 4 2 K 13 mK C at 4 2 K 75 mK C at 30 K Equivalence 53 mK C at 77 K 5 mK C at 77 K 50 mK C at 300 K 22 mK C at 300 K 30 mK C at 300 K 40 mK C at475K 90 mK C at 800 K Setpoint Display Resolution in Sensor Units 0 1 mV to 1 mV 0 01 Q to 0 1 Q 1 uV All thermocouple data are for uncompensated inputs T No Model 8001 Precision Option is available for thermocouples Error listed is for the instrument only 1 4 Introduction Lake Shore Model 320 Autotuning Temperature Controller User s Manual Table 1 2 Model 320 Specifications Thermometry Number of Inputs One Sensor Types Model 320 01 Silicon Diode Model 320 02 Platinum RTD Model 320 04 Thermocouple Accuracy Based on Model and Sensor Type Refer to Table 1 1 Update Rate 1 second Precision Curve Storage One 99 point curve entered via Serial Interface Control Control Digital three term PID with Autotune Automatic Control Mode P Pl or PID control user selectable Manual Control Mode Proportional GAIN 1 1000 integral RESET 1 1000 sec and derivative RATE 0 200 Control Stability Better than 0 1 K in
7. _ Lake Shore Model 320 Autotuning Temperature Controller User s Manual 24 Control Process Commands Continued SETP Input Returned Remarks Example SETP Input Returned Remarks Example Remote Operation Sets Setpoint In Units Chosen For Control SETP XXX X for temp Or SETP xX Xxx for voltage Nothing Fill in the setpoint parameter with a value from 0 through 999 9 for temperature or 0 through 2 499 for voltage Utilizes the free field format for the decimal point if in kelvin 1 SETP77 2 term will result in the display showing S 77 2 K 2 SETP123 term will resuit in the display showing S 123 0 K If in Celsius 3 SETP 123 term will result in the display showing S 123 0 C 4 SETP123 456 term will result in the display showing S 123 4 C Setpoint Status Query SETP XXX X for temp or X Xxx for voltage Returns current set point setting The value returned will be 6 digits a sign 4 digits and a decimal point If using the examples above in the SETP command discussion if in kelvin 1 SETP term will return 077 2 term 2 SETP term will return 123 0 term If in Celsius 3 SETP 123 term will return 123 0 term 4 SETP123 456 term will return 123 4 term 5 9 SOAN UAS EE Lake Shore Model 320 Autotuning Temperature Controller User s Manual 5 2 4 Curve Commands This paragraph provides a detailed description of each Curve Command The c
8. s commitment to continuous product improvement it is reasonable to expect that modifications will be made in the Model 320 software with time Some of these changes are the result of Customer feedback regarding operation on various cryogenic systems We encourage you to contact us with any observations or suggestions which you have regarding the use of this controller Also please return your warranty card to ensure that any software updates are sent to you MODEL 320 TEMPERATURE CONTROLLER SYSTEM DESCRIPTION The following are some of the major features of the Model 320 Autotuning Temperature Controller Input The Model 320 01 is a silicon diode temperature controller The Model 320 02 input is configured for a 100 C Platinum Thermometer PRTs The Model 320 04 Thermocouple controller is usable with several types of thermocouples 0 07 and 0 03 Ch AuFe E K and T thermocouples In addition the Mode 320 04 has electronic room temperature compensation standard introduction 1 1 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Sensors Typical electronic accuracy and resolution specifications for various sensors and temperature ranges are provided in Table 1 1 Precision For best precision individual sensors should be accompanied with the 8001 Precision Calibration Option which programs the instrument with calibration data for a specific sensor The algorithm within the instrument interpolates between data point
9. 232C serial port 2003 RJ11 to DB9 Adapter Connects RJ11 to a 9 pin RS 232C serial port 8271 30 Sensor heater cable assembly for diode and platinum sensors HTR 25 25 Q Cartridge Heater 25 W 1 4 inch diameter by 1 inch long Introduction 1 3 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Table 1 1 Instrument Electronic Information for Various Sensors and Temperature Ranges Model No 320 01 320 02 320 04 Sensor Type Silicon diode 100 Q Platinum RTD Thermocouple Sensor Temp Coefficient Negative Positive Positive Sensor Units Volts V Ohms Q Millivolts mV Input Range 0 2 5V 0 300 Q 15 mV Sensor Excitation 10 uA 0 05 1 mA 0 01 N A constant current constant current Example LSCI Sensor DT 470 CO PT 103 Ch AuFe 0 07 Sensor Temp Range 1 4 475K 30 800 K 1 4 325 K Standard Sensor Curve LSCI Curve 10 DIN 43760 NBS generated Typical Sensor Sensitivity 30 mV K at 4 2 K 0 19 Q K at 30 K 16 uV K at 4 2 K 1 9 mV K at 77 K 0 42 Q K at 77 K 20 uV K at 300 K 2 4 mV K at 300 K 0 39 Q K at 300 K 2 2 mV K at 475 K 0 33 Q K at 800 K Measurement Resolution Sensor Units 0 04 mV 5 ma 0 5 uV Temperature 1 3 mK at 4 2 K 26 mK at 30 K 31 mK at 4 2 K Equivalence 21 mK at 77 K 12 mK at 77 K 25 mK at 300 K 16 mK at 300 K 13 mK at 300 K 18 mK at 475 K 15 mK at 800 K Sensor Unit Display Resolution 0 1 mV to 1 mV 0 01 Q to 0 1 Q 1 uV Measurement Accuracy 0 2 mV 0 02 RDG 20 mQ 0 05 RDG 2 uV 0 05
10. 3 1 Model 320 Front Panel uti lr dr AAA 5 1 Serial Interface Connections B 1 Typical Cryogenic Storage Dewar LIST OF TABLES Table No Title 1 1 Instrument Electronic Information for Various Sensors and Temperature Ranges 1 2 Model 320 Specifications i2 sada il bik tek s ga AAS eas 2 1 Diode or Platinum Input Connections 2 2 Senso FQUIVOS Ae EN e did bs A 5 1 Serial Interface RS 232C Specifications B 1 Comparison of Liquid Helium to Liquid Nitrogen C 1 Standard Diode and Platinum Curves aaa C 2 Thermocouple Curves Chromel Vs AU ww eee ees C 3 Thermocouple Curves Chromel and Copper 2 cece eee eee Table of Contents This Page Intentionally Left Blank Lake Shore Model 320 Autotuning Temperature Controller User s Manual Table of Contents Lake Shore Model 320 Autotuning Temperature Controller User s Manual CHAPTER 1 INTRODUCTION 1 0 GENERAL 1 1 This chapter provides an introduction to the Model 320 Autotuning Temperature Controller The Model 320 was designed and manufactured in the United States of America by Lake Shore Cryotronics Inc The Model 320 Autotuning Temperature Controller is a microprocessor based instrument with digital control of a variable current output The Model 320 features including the following Autotuning Nonvolatile memory space to store one sensor calibration curve Serial Interface RS 232C Electrical Format is standard Thre
11. Configuration The instrument will power up in the configuration it was in when the power up feature was turned off Parameters including heater range setpoint gain reset rate units and curve number are stored in non volatile memory and preserved even when the line cord is disconnected from the unit To initialize the instrument do the following CAUTION H a precision option is present and the following process is performed the precision option will be erased Turn the instrument off Press and hold the Setup key and turn the instrument on Do not release the Setup key Continue to hold the Setup key down until the instrument goes in to normal operation Check the curve number for proper operation Refer to Paragraph 2 9 STAN Power Up Errors On power up the Model 320 does a check of the internal memory In the event that a problem exists an error message will be displayed on the instrument front panel ErO1 on the display indicates that there is a hardware problem in the instrument memory This error is not correctable by the user and the factory should be consulted Er02 on the display indicates that there is a soft error in the instrument memory In some situations this error can be user corrected by in tializing the Model 320 memory To reinitialize the memory please refer to the discussion in Paragraph 2 8 2 SENSOR CURVE SELECTION In order for the instrument to operate accurately in temperature it is nece
12. Nitrogen Argon Helium Carbon Dioxide Hydrogen and Fuel Gases Handling LHe LN Lake Shore Model 320 Autotuning Temperature Controller User s Manual APPENDIX C CURVE TABLES C1 0 GENERAL The following are curve tables applicable to the Model 320 Autotuning Temperature Controller Table C 1 Standard Diode and Platinum Curves Breakpoint D CURVE E1 CURVE DT 470 CURVE 10 Platinum 100 Ohm 1 0 00000 0 00000 0 00000 0 00000 2 0 19083 0 28930 0 09032 0 03820 3 0 24739 0 36220 0 12536 0 04235 4 0 36397 0 41860 0 18696 0 05146 5 0 42019 0 47220 0 29958 0 05650 6 0 47403 0 53770 0 42238 0 06170 7 0 53960 0 59260 0 56707 0 06726 8 0 59455 0 73440 0 68580 0 07909 9 0 73582 0 84490 0 76717 0 09924 0 84606 0 92570 0 83541 0 12180 0 95327 0 99110 0 89082 0 15015 1 00460 1 02840 0 94455 0 19223 1 04070 4 07460 0 98574 0 23525 1 07460 1 08480 1 02044 0 32081 1 09020 1 09090 1 05277 0 46648 1 09700 1 09810 1 08105 0 62980 1 10580 1 10800 1 09477 0 75044 1 11160 1 11500 1 10465 0 98784 1 11900 1 12390 1 11202 1 16270 1 13080 1 13650 1 11517 1 31616 1 14860 1 15590 1 11896 1 48652 1 17200 1 18770 1 12463 1 65466 1 25070 1 23570 1 13598 1 82035 1 35050 1 33170 1 21555 1 98386 1 63590 1 65270 1 29340 2 16256 1 76100 1 96320 1 36687 2 32106 1 90660 2 17840 1 44850 2 47712 2 11720 2 53640 1 64112 2 61391 2 53660 2 59940 1 68912 2 76566 2 59840 2 65910 1 69808 2 89830 6 55360 6 55360 6 55360 6 55360 Curve Tables C 2
13. PID PARAMETERS The following paragraph on manually setting PID parameters is presented in question and answer fo Q A rmat How do determine an appropriate gain setting for my cryogenic system First turn off both RESET and RATE Set in a nominal gain setting of 50 Make sure that the heater turns on if not increase the gain setting until the heater turns on Let the system stabilize Note that it will stabilize at some point below the set point Keep increasing the controller gain by factors of two until the system temperature begins to oscillate Adjust the gain for small sustained oscillations Measure the period of these oscillations for determining the correct setting for reset Reduce the gain by a factor of two to three until the temperature again becomes stable with time Be sure that you allow time at each setting for the system to stabilize if it will For some systems and cryogenic sensors with low sensitivity the maximum When enter a reset number how does that relate to my cryogenic system The reset number is an industrial control term which in the Model 320 corresponds to the number of repeats or time constants per 1000 seconds The time constant is 1000 divided by this number in seconds Consequently a reset number setting of 20 corresponds to a time constant of 50 seconds A system will normally take several time constants to settle into the set point e g the 50 second time constant if correct for the sy
14. 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 TRADEMARK ACKNOWLEDGMENT Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks Where those designations appear in this manual and Lake Shore was aware of a trademark claim the designations have been printed in initial capital letters and the or symbol used SoftCal Duo Twist Quad Lead amp Quad Twist are trademarks of Lake Shore Cryotronics Inc Formvar is a trademark of Monsanto Chemical Company Copyright 1992 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 permission of Lake Shore Lake Shore Model 320 Autotuning Temperature Controller User s Manual TABLE OF CONTENTS Chapter Paragraph Title I
15. Shore Model 320 Autotuning Temperature Controller User s Manual LIMITED WARRANTY Lake Shore Cryotronics Inc henceforth Lake Shore the manufacturer warrants this product for a period of twelve 12 months six months for sensors from the date of shipment During the warranty period under authorized return of instruments 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 six 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 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 THAT LAKE SHORE S LIABILITY WITH RESPECT TO THIS
16. Types And Recommendations The following are thermocouple wire types and recommendations for use at cryogenic temperatures For more information on thermocouples or other sensors refer to the Lake Shore Product Catalog Please note that the Chromel Gold lron 0 03 is not currently sold by Lake Shore Chromel Gold lron 0 07 amp 0 03 Consists of a Gold Au 0 07 and 0 03 at Iron Fe as the negative thermoelement and a Ni Cr alloy Chromel as the positive thermoelement This thermocouple is more widely used because of its relatively high thermoelectric sensitivity gt 15 mV K above 10K Type E Chromel Constantan Has the highest sensitivity among the three standard thermocouple types typically used at low temperatures types E K and T 8 5 mV K at 20K The best choice for temperatures down to 40K Chromel is the positive thermoelement Type K Chromel Alumel Has about one half the sensitivity of Type E at 20K Type K 4 1 mV K Recommended for continuous use in inert atmospheres Chromel is the positive thermoelement Type T Copper Constantan For use in vacuum as well as oxidizing reducing or inert environments down to 90K The copper element has high thermal conductivity making this thermocouple the least usable for cryogenic applications Sensitivity at 20K 4 6 mV K is similar to Type K Copper is the positive thermoelement Chromel CuFe 0 15 Measurable temperature range 4 to 300K Curve table applied from 4K
17. and potential energies of the atoms and molecules of bodies When the energies and velocities of the molecules in a body are increased the temperature is increased whether the body is a solid liquid or gas Thermometers are used to measure temperature The temperature scale is based on the temperature at which ice liquid water and water vapor are all in equilibrium This temperature is called the triple point of water and is assigned the value 0 C 32 F and 273 15 K These three temperature scales are defined as follows Boiling point of water 373 15 K 100 C 212 F Freezing point of water 273 15 K 0C 32 F Absolute zero OK 273 15 C 459 67 F Kelvin Celsius Fahrenheit A 4 Glossary Lake Shore Model 320 Autotuning Temperature Controller User s Manual ee APPENDIX B HANDLING OF LIQUID HELIUM AND NITROGEN B1 0 GENERAL Liquid Helium LHe and liquid nitrogen LNs may be used in conjunction with the Model 320 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 percent of the Earth s atmosphere while helium comprises only about 5 ppm Reference 1 Most helium is recovered from natural gas deposits Once collected and isolated the gases will liquify when properly cooled A quick comparison between LHe and LN is provided in Table B 1 Table B 1 Comparison
18. between these two points The heater output is a 1 amp current drive and does not have to be fused The Model 320 is designed to power a 25 heater for maximum heater output A larger heater resistance may also be used but will result in a lower maximum power output For example the output compliance voitage is 25 volts so that a 100 Q heater resistance allows a maximum power output of 6 25 watts 25V 2 1000 CAUTION The instrument has built in protection to prevent overheating If the heater load is below approximately 20 Q or if the heater loads are shorted the output will turn off If this occurs turn the instrument OFF and connect the proper load If the heater load is lass than 20 Q add a resistive load in series with the heater so that the total resistance between the HI and LO output terminals is approximately 25 Q Use care during heater installation to ensure Heater Hi is not shorted to ground Damage to the instrument can result from improper heater wiring Within a cryostat 30 gauge stranded copper lead wire ND 30 is recommended for connection to the heater The heater leads should not run coincident with the sensor leads due to the possibility of Capacitive pick up between the two sets of leads If the heater leads must be close to the sensor leads wind twist them in such a manner that they cross each other at ninety degrees Installation 2 3 Lake Shore Model 320 Autotuning Temperature Controller User s Manua
19. information Baud and bits per second bps are nof interchangeable Baud rate indicates how fast signals are being sent where bps shows the rate at which information is being transferred Binary Coded Decimal BCD A coding system in which each decimal digit from 0 to 9 is represented by four binary digits as follows 1 0 2893 7 348 11 0 0907 2 304 21 0 0285 0 7230 31 0 0089 0 2268 2 0 2576 6 544 12 0 0808 2 053 22 0 0253 0 6438 32 0 0080 0 2019 3 0 2294 5 827 13 0 0720 1 829 23 0 0226 0 5733 33 0 00708 0 178 4 0 2043 5 189 14 0 0641 1 628 24 0 0207 0 5106 34 0 00630 0 152 5 0 1819 4 621 15 0 0571 1 450 25 0 0179 0 4547 35 0 00561 0 138 6 0 1620 4 115 16 0 0508 1 291 26 0 0159 0 4049 36 0 00500 0 127 7 0 1443 3 665 17 0 0453 1 150 27 0 0142 0 3606 37 0 0045 0 1131 8 0 1285 3 264 18 0 0403 1 024 28 0 0126 0 3211 38 0 00397 0 1007 9 1 DECIMAL DIGIT BINARY CODE DECIMAL DIGIT BINARY CODE 0 0000 5 0101 1 0001 6 0110 2 0010 7 0111 3 0011 8 1000 4 0100 9 1001 Boiling Point The temperature at which a substance in the liquid phase transforms to the gaseous phase commonly refers to the boiling point of water which is 100 C 212 F at sea level Glossary A 1 _ Lake Shore Model 320 Autotuning Temperature Controller User s Manual Celsius C A temperature scale that registers the freezing point of water as 0 C and the boiling point as 100 C under normal atmospheric pressure Formerly known as centigrade Orig
20. its value with setpoint changes resulting in new PI settings Obviously if you prefer less RATE set the rate setting at something less than 100 Remember however in many cryogenic systems rate will not be required anyway and is consequently set at 0 An application note titled Fundamentals for Usage of Cryogenic Temperature Controllers is included with Appendix D This application note should be read in detail if you are not familiar with cryogenic temperature controllers Operation 3 3 3 3 1 3 3 2 3 4 3 4 1 3 4 2 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Setpoint To change the setpoint press the Scroll key until the setpoint is shown in the display An S will be the first digit Use the Left and Right cursor keys to move to digits which need to be changed Flashing will indicate the digit to be changed The Up and Down cursor keys will change the value of the particular digit Enter the new setpoint with the cursor keys Press the Scroll key to complete the operation If the setpoint is displayed in degrees Celsius or millivolts Model 320 04 the Up key can be used to toggle the sign of the set point when it is flashing The setpoint is limited in temperature to the range of the curve being used for control Table 2 2 gives these limitations in kelvin for curves 00 through 04 There is no setpoint limiting for the control channel when controlling in sensor units even if
21. to 273K Sensitivity gt 11 mV K O 4 2K Lower in cost than Gold Chromel thermocouples and physically stronger Special Features 4 3 Lake Shore Model 320 Autotuning Temperature Controller User s Manual dE A PP NENE AENA J U pus i e This Page Intentionally Left Blank SA EEE RARA 4 4 Special Features Lake Shore Model 320 Autotuning Temperature Controller User s Manual CHAPTER 5 REMOTE OPERATION 5 0 GENERAL 5 1 This paragraph provides a description of the SERIAL I O Interface RS 232C is a standard of the Electronics Industries Association EIA describing of one of the most common interfaces between a computer and electronic equipment To utilize this interface a Customer supplied computer is required equipped with a RS 232C Interface port When a connection is made between the computer and the Model 320 the Serial Interface permits remote monitoring and control of the Model 320 control functions which in turn controls the operation of the Model 320 See Figure 5 1 The Serial Interface is capable of bi directional communication i e it can both transmit and receive information In transmission Tx mode RS 232C Interface converts parallel information to serial information and sends that information over a cable up to 50 feet long or longer with proper shielding In the receiving Rx mode the RS 232C Interface converts the serial information back to parallel information for processing SERIAL INTERFACE DESCRIP
22. unenergized position PID Acronym for Proportional Integral and Derivative A three mode control action where the controller has time proportioning integral auto reset and derivative action The integral function also known as reset automatically adjusts the temperature at which a system has stabilized back to the set point temperature thereby eliminating droop in the system The derivative function also known as rate senses the rate at which a system s temperature is either increasing or decreasing and adjusts the cycle time of the controller to minimize overshoot or undershoot Pop off Another term for relief valve Prefixes Standard International System of Units SI prefixes used throughout this manual are as follows Fact Prefi Symbol E Prefi Symbol 1018 exa E 107 deci d 1015 peta P 102 centi C 1012 tera T 103 milli m 109 giga G 10 micro u 106 mega M 102 nano n 103 kilo k 10712 pico p 102 hecto h 10 15 femto f 10 deka da 10 19 atto a 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 Quench A condition where the superconducting magnet goes normal i e becomes non superconductive When this happens the magnet becomes resistive heat is generat
23. various types of cryogenic loads to be different in thermal properties by several orders of magnitude at the same temperature Consequently the algorithm complexity of the problem is much greater than that for well behaved high temperature loads Will Autotuning work for all types of systems There will undoubtedly exist conditions and systems where you are better off using manual control An example might be an extremely fast cryogenic system load where it is difficult for the controller to characterize the load Under these conditions manual control should undoubtedly be used MODEL 320 04 THERMOCOUPLE CONTROLLER OPERATION The Model 320 04 thermocouple controller is designed to accommodate thermocouple sensors Chromel AuFe 0 07 Chromel AuFe 0 03 E K and T thermocouples are supported with internal curves that enable the controller to operate in temperature units C and K as well as voltage in millivolts The Model 320 04 utilizes a secondary temperature sensor to monitor the Reference Junction room temperature and provide curve compensation Thermocouple Reference Junction Compensation can be disabled in order for the Model 320 04 to be used with external compensation techniques Sensor Attachment Thermocouple leads are attached to the terminal block by aluminum screws Be sure to tighten the terminal screws carefully Loose connections will result in unstable readings and control The leads must be connected with the prop
24. wae aa is Ad EEN T B 1 Handing lt s rdiasgsa dimadassotabae EE B1 0 M N Maintenance ET EE 6 1 Manual Control Settings ET Te Et EE E 3 4 1 Rate D a Ate Deena OS ANA Be A ju K 3 4 3 Reset tege So a A A RE Uae ta oa ae s 3 4 2 Manually Setting PID Parameters 3 5 O VDEI9NOM caries dani iaa a das n ass eos 3 0 Options and ACCOSSOMOS aria AAA SESE AAA A EAS AS 1 2 Power Up Power Up Conllgurauon airada 2 8 2 POWO OD EMOS sig aie Sy ek ee ato ad hw PN Pa a in a BOTS Dee eee 2 8 3 POWERUG SCQUENCE ee prea at th sh ee Se eee Ee eed BL hie Ge ees 2 8 1 Precision Options Models 8000 8001 and 8002 05 0 cee eee nee eens 2 10 An AAA HacK MOUNINO ss a een bee eee eee eee A 2 12 Rear Panel Detinition Of CONNECHIONS pci a EAS AI A AA A eee 2 3 typical Model 320 Rear Panel oscar Eier ee si Sad F2 1 Repackaging For Shipment stat RA ira 2 2 Alpha index 2 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Paragraph Figure F Subject Table T Number S Salen Summary arar aia ane ee RRA A A EE 1 3 Sato O UMDO S iia ARA AR e ee EE eres 1 4 Sensor e EE TT SE vesi do ii Se 2 9 T2 2 Sensor Input Connections Diode Model 320 01 Platinum Model 320 02 Connections 2 7 1 F2 2 T2 1 Thermocouple Model 320 04 Connections 0 0 aaa 2 7 2 Thermocouple Compensation xe ir as a re eg KE A ee babe 2 7 3 Serial Interface RS 232C Ee te H UL A EE 5 1 1 F5 1 Sample BASIC
25. 2 2 Channel Commands 5 6 5 2 3 Control Process Commands 0 aa 5 7 5 2 4 Curve COMMANGS gc ku a Kaa ss OE ia BAAS eA GEER 5 10 6 SERVICE AND CALIBRATION 6 1 6 0 Gena SO a a a S ta ENEE EE A sa 6 1 6 1 General Maintenance 6 1 6 2 Fuse Replacement 6 1 6 3 Line Voltage Selection 6 1 6 4 Model 320 01 Calibration 6 2 6 5 Model 320 02 Calibration 6 3 6 6 Model 320 04 Calibration 6 4 APPENDIX A GLOSSARY OF TERMINOLOGY A 1 APPENDIX B HANDLING LIQUID HELIUM AND NITROGEN B 1 B1 0 Jules lee EE B 1 B2 0 FIOPBMIES did ee Ee EE ear ee B 1 B3 0 Handling Cryogenic Storage Dewars B 1 B4 0 Liquid Helium and Nitrogen Safety Precautions B 2 B5 0 Recommended First Aid B 2 APPENDIX C CURVE TABLES C 1 C1 0 EC EE C 1 APPENDIX D APPLICATION NOTES D 1 D1 0 GENTA EE EE D 1 ALPHABETICAL INDEX corn s na bs Eeer let INDEX 1 Table of Contents Lake Shore Model 320 Autotuning Temperature Controller User s Manual LIST OF ILLUSTRATIONS Figure No Title 1 1 Model 320 Temperature Controller Front Panel 2 1 Typical Model 320 Rear Panel xs micniidn cirrosis ee as 2 2 Sensor Connections 0d A EE E 2 3 Model 2001 RJ11 Cable Assembly Wiring Details o oooooooo ooo 2 4 Model 2003 RJ11 to DB9 Adapter Wiring Details a 2 5 Model 2002 RJ11 to DB25 Adapter Wiring Details
26. 299 99 Q 0 00 Q looks like 0 00000 and 299 99 2 looks like 2 99990 Input range is 15 to 15 Add 15 mV to make all positive 0 30 mV and multiply by 100 to make look like 0 3 00000 V For example a thermocouple voltage of 5 0000 mV would be entered as 1 00000V To view a typical output after using this command to input all the information see the example under the CURV command When entering omit the temperature coefficient the number of points and endpoints The Model 320 determines and stores whether the curve is a positive or negative coefficient curve Based on temperature coefficient the Model 320 then stores the curve end points and also adds the number of points 5 11 Lake Shore Model 320 Autotuning Temperature Controller User s Manual a OE Curve Commands Continued CURV Input Returned Remarks Example mn e e RN 5 12 Curve Number Information Query CURV XX AA BBBBBBBBBBBBBBBBBB C XX YYYYYY ZZZZ User must provide curve number 00 thru 11 with guery The instrument will return header line and all point information for that curve Information returned is defined as follows A Curve number The value will be from 00 to 11 B Curve description 18 character information line All 18 characters may not be used C Temp coefficient N represents negative temperature coefficient while P represents positive X Number of points The number of data points for t
27. 3 5 Manually Setting PID Parameters 4 SPECIAL FEATURES eriin ss sa A SORE Hae ae ha 4 0 Geneak causado ee E 4 1 Automatic Tuning st s j asos a 4 1 1 Initial Values of PID Parameters in Autotuning Mode 4 1 2 Minimum Overshoot 4 1 3 Minimum Time To Setpoint 4 1 4 SS EAr A E E N e 4 2 ATI res simon AE D s iaa Table of Contents DO D mesch I I 1 D D aaa Y Y Y 0 0 O 01010014 SG Y O GO G GO GO GO C 1 et 1 4 wech Y Y Y Y YY WWW C Niza ch GG A A A A AA OM MOOD os ba bb bb bb Lake Shore Model 320 Autotuning Temperature Controller Users Manual Chapter Paragraph Title Page 4 3 Model 320 04 Thermocouple Controller Operation 4 2 4 3 1 SONSOFAUACHINGNM merida rara kd sub 4 2 4 3 2 Thermocouple Curve Selection 4 2 4 3 3 Thermocouple Compensation From Front Panel 4 2 4 3 4 Thermocouple Compensation From Remote Interface 4 2 4 3 5 Internal Offset Adjustment 4 3 4 3 6 GUIVO e ut EE 4 3 4 3 7 Thermocouple Wire Types and Recommendations o o o o o 4 3 5 REMOTE OPERATION 002 cr A A E 5 1 5 0 Gonera apean a o es 5 1 5 1 Serial Interface Description 5 1 5 1 1 Serial Interface Configuration 5 2 5 1 2 Model 320 Serial Interface Settings 5 2 5 1 3 Sample BASIC Serial Interface Program 5 2 5 2 Serial Interface Command Summary 5 4 5 2 1 Display Commands visi ss Kaa Geniss cs 5 5 5
28. A 3 3 2 DRDO errre Se aie then E A Eege 3 3 1 Control Sensor edel len te WEEN 3 2 3 Bettel ir A A cado 3 2 2 Selecting Control Units ii A Sie Pde oe ea ed eed ka S Ga a KA a 3 2 1 Curves Standard Diode and Platinum Curves 1 ccc aa T C 1 Thermocouple Curves Chromel and Copper T C 3 Thermocouple Curves Chromel Vs Au T C 2 D Description Model 320 Temperature Controller 0 ccc a 1 1 Dewar Typical Cryogenic Storage F B 1 E Environmental Requirements 2 4 F Front Panel Definition of Controls vetar da 3 1 Model 320 Fr nt Panel Ate erg gege En AAA NTE RE et F1 1 F3 FUSG E EE 6 2 G General Maintenance 6 1 Glossary Of Terminology 2946655 das mods da dnia ee See A1 0 Grounding and Shielding 2 5 Alpha Index 1 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Paragraph Figure F Subject Table T Number H Handling Liquid Helium and Liquid Nitrogen B1 0 Hardware Options and Accessories wisc AS da AAA 1 2 Healer SEUD Lai ts EE EE 2 6 1 J K Inspection anG UNPACKING zse lt uisamediaudn ks kmis e EE 2 1 JC TE e D uses idad a AA ais 2 0 Instrument Electronic Information for Various Sensors and Temperature Ranges T1 1 INTOQUCION dises tss oda AA S d a aj ba S a 1 0 L LINO VONAGE 56162101 se oan tents ate A ooh eS Bee saktas Mee a s ae as 6 3 Liquid Helium and Liquid Nitrogen OMPAFI OTI 33 vielas to de
29. AU 0 07 Fe AU 0 03 Fe Type E Type K Type T Values are for thermocouples with compensation Uncompensated the thermocouple can use the full 15 mV range PRECISION OPTIONS MODELS 8000 8001 AND 8002 05 There are three types of precision options available for the Model 320 The Mode 8000 Precision Option generates the data table from a Lake Shore calibrated sensor The maximum number of data points is 99 A typical calibration precision option ranges between 30 and 40 points depending on the sensor type and temperature range of the calibration The data and accuracy of the fit is supplied to the user as a separate document This information can be entered by the user over the serial interface Prior to shipment Lake Shore can also generate a custom sensor response curve from the individual sensor calibration as indicated in the above paragraph and store it in the Model 320 via the Model 8001 Precision Option The data and accuracy of the fit is then supplied to the user as a supplement to this manual The Model 8002 Precision Option is used when the customer already owns a Model 320 and wants the additional sensor calibration stored in the instrument Lake Shore stores the calibration data in a NOVRAM and sends the programmed IC to the customer The IC is then installed in the instrument by the customer The user should be prepared to supply the Model 320 serial number at the time of order SERIAL INTERFACE RS 232C SETUP T
30. Cursor The cursor or arrow keys are used with the function keys to make changes in the specific parameters selected on the display When entering number data setpoint control parameters the Left and Right keys select the digit that will be changed indicated by the digit flashing The Up and Down keys change that digit Power The sole function of the power key is to turn the instrument power on and off CONTROL SENSOR The Control reading can be displayed in temperature K or C or the sensor units associated with the input The units selected are shared by the Control Sensor and the Setpoint The control reading is displayed on power up If it is not shown press the scroll key repeatedly The control reading is the value that does not have an S or Heat in the beginning Selecting Control Units Control units can be changed by the following procedure 1 Press the Setup key repeatedly until the units are displayed 2 Press the Up arrow key to toggle units between K C or the appropriate sensor units NOTE Setpoint units match control units Control Resolution Temperature Resolution In temperature mode the sensor reading is displayed in K or C with a display resolution of 0 1 degrees NOTE This is display capability and not system resolution or accuracy of the reading Voltage Resolution Models 320 01 and 320 04 Only In voltage mode V the display has a resolution of 0 1 millivolt mV below 2 volts and 1
31. H breathing is difficult give oxygen Get medical help 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 areas 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 transfers accomplished and systems operated in open and well ventilated areas Persons transferring LHe and LN gt 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
32. IPMENT If it is necessary to return the Model 320 sensor 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 Instruments may not be accepted without an RGA number When returning an instrument for service the following information must be provided before Lake Shore can attempt any repair A Instrument model and serial number B User name company address and phone number C Malfunction symptoms D Description of system E Returned Goods Authorization RGA number Wrap instrument in a protective bag and use original spacers to protect controls Repack the system in the LSCI shipping carton if available and seal it with strong paper or nylon tape Affix shipping labels and FRAGILE warnings Write the RGA number on the outside of the shipping container or on packing slip Installation 2 1 2 3 2 2 Lake Shore Model 320 Autotuning Temperature Controller User s Manual HEATER SERIAL VO o FUSE DATA 3AG SB 50 60 HZ AC 90 125V 0 50A SENSOR INPUT V ied Use Only With A 250V Fuse S 320 U 2 1 Figure 2 1 Typical Model 320 Rear Panel DEFINITION OF REAR PANEL CONNECTIONS This paragraph provides a description of the Model 320 rear panel connections The rear panel consists of the power and fuse assembly Serial I O Connector Sensor Input Connector and Heater O
33. NE INPUT 1 BS INPUT RESPONSE ONLY IF QUERY DS INPUTS 1 1 GET LINEFEED PRINT BS OUTPUT TO SCREEN L2 PRINT GO TO L1 GET NEXT COMMAND STRING 5 2 Remote Operation Lake Shore Model 320 Autotuning Temperature Controller User s Manual The following are examples using this BASIC program Input provided by the user is shown in bold type ENTER COMMAND CUNI K Set Control Units Instrument will set unit to kelvin units ENTER COMMAND CUNI Control Units Query Instrument will return appropriate unit where K kelvin K ENTER COMMAND CDAT Sensor Data Query Instrument will return appropriate sensor reading 77 6 ENTER COMMAND TUNE 3 Set Autotuning Status Instrument will set Autotuning to PID ENTER COMMAND TUNE Autotuning Status Guery Instrument will return appropriate setting where 0 Manual 1 P 2 Pl and 3 PID 1 ENTER COMMAND RANG 0 RANG Combination command of setting the heater to off and requesting heater status where 0 off and 1 on 0 ENTER COMMAND Query commands end with a The common commands along with a brief description recognized by the Model 320 are summarized by function in Paragraph 5 2 Additional notes are as follows Commands may be chained together when separated by a semi colon Multiple queries cannot be chained Queries have the same syntax as the associated setting command followed by a question mark They should return the same information that i
34. NTRODUCTION EE 1 0 ET TEE 1 1 Model 320 Temperature Controller Description 1 2 Hardware OPUONS 24 5 4 vont ewes A AS 1 3 DAISY SUMMA ui A aed gs A ads Bee ege 1 4 Saloy dl 2 INSTALLATION Ae tee a EE E 2 0 Genaral sists S S E Eo a a es 2 1 Inspection and Unpacking 2 2 Repackaging For Shipment 2 3 Definition of Rear Panel Connections 2 4 Environmental Requirements 2 5 Grounding and Shielding 2 6 FIGALCl AA A ea E A E E EA 2 7 Sensor Input Connections 2 7 1 Diode Model 320 01 Platinum Model 320 02 Connections 2 7 2 Thermocouple Model 320 04 Connections 2 7 3 Thermocouple Compensation 2 8 POWET UP 22 33 g EE 2 8 1 Power UD Sequence EE 2 8 2 Power Up Configuration e ENEE EN be s s s are Erde 2 8 3 POWE UP EITOFS diia A e a a 2 9 Sensor Curve Selection 2 10 Precision Options Models 8000 8001 and 8002 05 2 11 Serial Interface RS 232C Setup ccc cee ee eee nes 2 12 RACK MOUNN EEN d OPERATION net conta ce ee as ai ge ger al s os 3 0 GENSA usada toda tadas 3 1 Definition of Front Panel Controls 3 2 Belt EEN 3 2 1 Selecting Control Units 3 2 2 Belle E UE REES 3 2 3 Control Input d CEET 3 3 Control Fundamentals 3 3 1 EE O 3 3 2 HOALE ins 6 bee heey ede asai Aka we Pe ee eee ae ee 3 4 Manual Control Settings 3 4 1 ET Un was He NN 3 4 2 O EE EE 3 4 3 Rato LD ebe O eta nas tads DR
35. 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 is 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 Cail a physician immediately References 1 Linde Union Carbide Document No L 3499H Dated December 1988 Safety Precautions for Oxygen
36. Serial Interface Program 5 1 3 Delfi Tesi daa dd js era ne S A Aa baaa 5 1 2 Te WEE EE 2 11 SDECHICAUIONS lt EE EE T5 1 Serial interface Cable Adapters Model 2001 RJ11 Cable Assembly Wiring Details F2 3 Model 2002 RJ11 to DB25 Adapter Wiring Details F2 5 Model 2003 RJ11 to DB9 Adapter Wiring Details F2 4 Serial Interface Command Summary Channel Commands EE EEN 5 2 2 GEELEN COMMANGS zssivis ssm e ee k ts sd s kas Sad Ee 5 2 3 GUIVO COMMANOS ds sus s d ja Dd ata A ants gs ds Sa SAS 5 2 4 Display Commands s ss ni a id ss dod dao degot Sean S S gs a t r im 5 2 1 Service and GaliGration dsk duda daa a 6 0 OCIA CANS scale ss eet aos 9 nea Ben De 4 0 Speciications M d l 3 20 eur id a a e EA T1 2 T Thermocouple Controller Operation Model 320 04 GUIVE FORMAL EE 4 3 6 internal Offset Adjustment sche we dine he we a te A eee eas 4 3 5 DENSOMAUACMINGML ri A avon re eg nate g EA E 4 3 1 Thermocouple Compensation From Front Panel 4 3 3 Thermocouple Compensation From Remote Interface 4 3 4 Thermocouple Curve Selection ege CH eet e A eee ieee becca EC 4 3 2 Thermocouple Wire Types and Recommendations 4 3 7 U V W X Y Z Alpha Index 3 Lake Shore Model 320 Autotuning Temperature Controller User s Manual This Page Intentionally Left Blank Alpha index 4 Lakeshore CRYOTRONICS INC 64 East Walnut Street Westerville Ohio 43081 USA Telephone 614 891 2243 Telex 245415 CRYO
37. TION The Serial Interface hardware configuration is described in Paragraph 5 1 1 Serial Interface settings are described in Paragraph 5 1 2 A sample BASIC program to establish communications between the computer and the Model 320 is provided in Paragraph 5 1 3 Commands are divided into four types Display Channel Control Process and Curve Individual commands are described in Paragraph 5 2 LSCI Model 2002 RJ11 to DB25 Adapter SERIAL 1 0 Serial Interface Output on rear of Model 320 Use whichever adapter that matches your computer serial interface connector To Customer Supplied Computer DB25 Serial Interface Connector LSC Model 2003 RJ11 to DB9 Adapter KA D GE GE dE GE Staal e SEH ARO RS ARS PDA AR A IAA AKTS SN Kee RAN LSC Cable Assembly NN To Customer Supplied Computer DB9 Serial Interface Connector S 320 U 5 1 Figure 5 1 Serial Interface Connections Remote Operation 5 1 Lake Shore Model 320 Autotuning Temperature Controller User s Manual 5 1 1 Serial Interface Configuration The following is a technical description of the RS 232C Interface configuration Communication parameters are defined in Table 5 1 Terminators are fixed to carriage return CR and Line Feed LF A query may be added to the end of a command string if the instrument is required to return information For example CUNI K UNIT commands the Model 320 to set the temperature units to kelvin followe
38. TRON WTVL Fax 614 891 1392 perma 320 Autotuning Temperature Controller Heater Setup Sc Autotuning Building on the accuracy and convenience of Lake Shore Thermometry the new Model 320 Autotuning Controller offers a simple low cost answer to basic control needs The autotune feature increases the user s efficiency by automatically selecting and adjusting the correct porpor tional GAIN integral RESET and derivative RATE in virtually minutes Time spent adjusting or fine tuning the controller is eliminated leaving the user with more time to experiment with something other than controller settings Acryogenic system is acomplex arrangement ofthermal resistances and heat capacities which are represented by thermal lags and thermal time constants The 320 Controller analyzes this system s operating parameters on line The controller s Autotuning function deter mines the proper values for gain rate and reset Once set the PID values are only modified when the system characteristics change Features Autotuning no need for the user to select PID parameters Manual settings of PID parameters via front panel entry Three Models 320 01 Silicon Diodes 320 02 100 ohm Platinum Resistors or 320 04 Thermocouples Ability to store one sensor calibration curve RS 232C serial interface 25 watt DC heater output 8 character alphanumeric LED display for nigh visibility Electronic accuracy and co
39. Unit Measure resistance of RTEsr to 4 1 2 places with a 4 lead measurement Write down resistance Attach test connector and put multimeter across RTEST Plug in instrument and place Power switch to on in position Turn heater off Allow unit to warm up for 1 hour Adjust current source with R5 until current through RTesr is 10 pA For a precision 100 KQ resistor DMM voltage should read 1 0000 V For a less accurate resistor 100 25 KQ for example DMM voltage should read 1 0025 V 8 Remove test connector and place a short between connector pins 2 and 4 9 Configure unit to display in volts see Chapter 3 10 Adjust R6 until display toggles between 0000 and Err27 11 Remove short between connector pins 2 and 4 Attach test connector and put multimeter across RTEST 12 Adjust R7 until display reads same as multimeter 1 Vdc 13 Place Power switch to off out position 14 Disconnect test connector NO a N 6 2 Service Lake Shore Model 320 Autotuning Temperature Controller User s Manual 6 5 MODEL 320 02 CALIBRATION To calibrate the Model 320 02 requires a digital multimeter DMM with a 4 1 2 digit display capable of 4 lead resistance measurement and a test connector wired as follows 3 l 4 V Rr EST 100 2 2 V 1 CH where Rrest should be nominal 100 Q and as temperature stable as possible 20 50 ppm C Line voltage is present inside the box Only qualified personnel should proceed bey
40. Units Query CUNI Returned K C V R or M Remarks Used to query the unit for current control units information The character returned will be K for kelvin C for Celsius V for Volts R for Ohms or M for millivolts to the query Identification Query IDN Manufacturer model number 0 firmware date Identifies the instrument model and software level 0 in the returned syntax is in place of the serial number LSCI MODEL320 0 103190 term Set Control Units Status CUNI K CUNI C OTCUNI S Nothing Set units parameter with K for kelvin C for Celsius or S for the appropriate sensor units volts ohms or millivoits If operating in kelvin with a Model 320 01 CUNI S term makes the units volts being the sensor units for a diode sensor The Model 320 02 platinum controiler has sensor units of ohms and the Model 320 04 thermocouple controller has sensor units of millivolts CUNI Input Returned Remarks Control Units Query CUNI K C V R Or M Returns current control units setting The character returned will be K for kelvin C for Celsius V for volts R for Ohms or M for millivolts CDAT Input Returned Remarks Example Sensor Data Query CDAT 000 00 term A free field is active here The value returned is 7 characters a sign 5 digits and a decimal point 1 2345 term voltage 123 4 term Celsius 234 5 term kelvin or Celsius Remote Operation Po
41. User s Manual Model 320 Temperature Controller Obsolete Notice This manual describes an obsolete Lake Shore product This manual is a copy from our archives and may not exactly match your instrument Lake Shore assumes no responsibility for this manual matching your exact hardware revision or operational procedures Lake Shore is not responsible for any repairs made to the instrument based on information from this manual LakeShore Lake Shore Cryotronics Inc 575 McCorkle Bivd Westerville Ohio 43082 8888 USA Internet 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 Obsolete Manual 5 January 1993 Lake
42. a curve is selected Heater Heater Display The heater current is displayed by pressing the Scroll key until it is shown in the display Units are percent of full scale heater current If the heater is off the display will show Heat OFF To toggle the heater on or off simply press the Heater key The indicator to the left of the Heater key will light when the heater is on NOTE If the heater load drops below approximately 20 Q the actual output will turn off However the display may still show a of heater display other than zero MANUAL CONTROL SETTINGS In manual mode the instrument will accept Gain Reset and Rate parameters from the user and provide three term PID control To put the instrument in Manual Control Mode press the Setup key until the display shows the tuning selection P Pi PID or Manual Press the Up arrow key until the unit displays Manual Gain P Adjustment of the gain or the proportional P part of the control function gives the controller an overall range of 1 to 999 To enter a gain value press the Setup key until GAIN is shown The display will show the current gain setting Use the Left and Right keys to cursor to the digit to be changed It will flash to indicate that it can be incremented or decremented with the Up or Down key When the gain value is set press the Setup or Scroll key to enter it Reset I Adjusts the reset time constant of integrator I in the control function Ef
43. a properly designed system for diode and platinum sensors Setpoint Resolution 0 1 in Temperature K or C Heater Output Type Analog DC Current Source Heater Setting Resolution 15 bit Max Power To Heater 25 W Max Current To Heater 1 A Heater Output Compliance 25 V Heater Load 20 Q or greater to operate 25 required for full power Heater Noise 0 005 of full scale power Front Panel Display 8 digit Alphanumeric LED Display Units Temperature in K or C Sensor units in volts 320 01 ohms 320 02 or millivolts 320 04 Annunciator Heater On Temperature Resolution 0 1K or C Sensor Units Resolution Same as setpoint resolution Keypad Scrolls through sensor reading setpoint and heater current Setup of units curve number manual control settings tuning selection filter and BAUD rate Interface Serial Interface 300 or 1200 baud RJ11 connector RS 232C electrical standard General Ambient Temperature Range 15 35 C Power Requirements 90 125 or 210 250 VAC 50 or 60 Hz 65 watts Size 105 mm wide x 132 mm high x 280 mm deep 4 2 x 5 2 x 11 inches Weight 2 7 kilograms 6 pounds ENEE EE Introduction 1 5 Lake Shore Model 320 Autotuning Temperature Controller User s Manual 1 3 1 4 SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation service and repair of this instrument Failure to comply with these precautions or with specific warning
44. d by a request that the Model 320 return the temperature units to confirm the change had been made The connector used for the serial interface is a standard 6 wire RJ 11 telephone jack Lake Shore offers the Model 2001 10 foot Cable Assembly Model 2002 RJ 11 to DB25 Adapter and the Model 2003 RJ 11 to DB9 Adapter Table 5 1 Serial interface RS 232C Specifications Transmission Three Wire Connector RJ 11 Modular Socket Timing Format Asynchronous Transmission Mode Half Duplex Baud Rate 300 or 1200 Bits per Character 1 Start 7 Data 1 Parity and 1 Stop Parity Type Odd Data Interface Levels Transmits and Receives Using EIA Voltage Levels Terminator LF OAH 5 1 2 Serial Interface Settings The Model 320 will operate at two different Baud rates 300 or 1200 Press the Setup key until the BAUD rate is displayed The A key will toggle between the two settings 5 1 3 Sample BASIC Serial Interface Program The following is a sample RS 232C Interactive serial poll routine for the Model 320 written in Quick Beginner s All purpose Symbolic Instruction Code BASIC INTERACTIVE SERIAL POLL ROUTINE FOR 320 WRITTEN FOR QUICK BASIC CLS OPEN STATEMENT FOR 300 BAUD OPEN COM1 300 0 7 1 RS FOR RANDOM AS 1 LEN 256 Li INPUT ENTER COMMAND AS ENTER COMMAND STRING FROM KB PRINT 1 AS CHRS 13 CHR 10 SEND STRING TO 320 WITH TERM IF MID A LEN A 1 lt gt THEN GO TO L2 TEST QUERY SENT LI
45. d nitrogen ice etc Allow the system to stabilize to the reference temperature 2 Onthe front panel of the Model 320 04 select the desired temperature units 3 Tum on thermocouple compensation 4 Adjust the offset adjustment trimpot R8 so that the displays read the reference temperature NOTE The offset adjustment compensates for the thermocouple used in the calibration If another thermocouple is attached or the thermocouple has aged or the configuration of the system is changed then the offset adjustment must be repeated Curve Format The card is hardware limited to reading input between 15 mV and 15 mV All curves should be limited in temperature so not to exceed these values If thermocouple compensation is desired the thermocouple curve must be normalized to zero in degrees Celsius Compensation also limits the practical range by approximately the room temperature voltage of the thermocouple used The Model 320 04 is designed to operate on sensor curve data in the range of 0 00000 to 3 00000 volts so thermocouple voltage must be converted to this range before it is entered into a user curve table To obtain the proper table value from a thermocouple voltage it must be summed with 15 millivolts to make it positive and multiplied by one hundred to shift the resolution A 15 0000 millivoit thermocouple voltage will result in a 0 00000 volt table value and 15 0000 millivolts will result in 3 00000 volts Thermocouple Wire
46. d within the range of 15 35 C with reduced accuracy To prevent electrical fire or shock hazards do not expose this instrument to rain or excess moisture GROUNDING AND SHIELDING 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 Model 320 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 320 is tied directly to earth ground for interface communication The low side of the heater output is directly connected to earth ground NOTE Do not attach the shield to earth ground at the sensor end Shield sensor cables whenever possible Attach the shields to the shield pin provided in the connector HEATER SETUP The heater output of the Model 320 is brought out the back panel as a Dual Banana Jack A mating connector is supplied Current is driven from the HEATER HI connection to the HEATER LO connection Heater LO is connected to earth ground A resistive heater load of 25 Q or more should be connected
47. e Models available Silicon Diode 320 01 100 2 Platinum Resistor 320 02 Thermocouple 320 04 Eight character alphanumeric LED display for high visibility Simple scroll type display with cursor key entry Capability of reading sensors with 0 1 kelvin accuracy or better Isolated current source allows true 4 wire sensor readings Control Stability to 0 1 or better in K or C 25 watts of heater power Variable DC current source output Small 1 4 DIN package If you have just received your new Model 320 please proceed to Chapter 2 and become familiar with the installation instructions Instrument operational information is contained in Chapter 3 Chapter 4 contains information on Model 320 special features Details on remote operation using the Serial I O Interface is contained in Chapter 5 Service and calibration information is provided in Chapter 6 For reference various appendices are included Finally an alphabetical index is included at the end of the manual We welcome your comments concerning this manual Although every effort has been made to keep it free from errors some may occur When reporting a specific problem please describe it briefly and include the appropriate paragraph figure table and page number Send comments to Lake Shore Cryotronics Attn Technical Publications 64 East Walnut Street Westerville Ohio 43081 2099 The material in this manual is subject to change without notice Due to Lake Shore
48. e reset parameter can be filled in with an integer from 0 through 999 Reset corresponds to the Integral t portion of the PID Autotuning control aigorithm 5 7 Lake Shore Model 320 Autotuning Temperature Controller Users Manual Control Process Commands Continued RSET Reset Query Input RSET Returned xxx Remarks Returns current reset setting The value returned is an integer from 000 through 999 Reset corresponds to the Integral I portion of the PID Autotuning control algorithm RATE Manual Mode Rate Setting Input RATE XXX Returned Nothing Remarks The rate parameter can be filled in with an integer from 0 through 100 Rate corresponds to the Differential D portion of the PID Autotuning control algorithm RATE Rate Query Input RATE Returned xxx Remarks Returns current rate setting The value returned is an integer from 0 through 100 Rate corresponds to the Differential D portion of the PID Autotuning control algorithm RANG Set Heater Status Input RANG 0 Or RANG 1 Returned Nothing Remarks Sets heater status where 0 off and 1 on RANG Heater Status Query Input RANG Returned oorl Remarks Returns current heater status where 0 off and 1 on H EAT Heater Power Status Query Input HEAT Returned XXX Remarks Returns the percent of full scale heater current where the returned number represents one percent increments up to 100 5 8 Remote Operation
49. ed Liquid Helium is boiled off and the Magnet Power Supply will shut down due to the sudden increase in current demand Relief Valve A type of pressure relief device which is designed to relieve excessive pressure and to reclose and reseal to prevent further flow of gas from the cylinder after reseating pressure has been achieved Roman Numerals Letters employed in the ancient Roman system of numeration as follows 1 VI 6 L 50 li 2 VII 7 C 100 11 3 VI 8 D 500 IV 4 IX 9 M 1000 V 5 X 10 Root Mean Square RMS The square root of the average of the squares of the values of a periodic quantity taken throughout one complete period It is the effective value of a periodic quantity Susceptance In electrical terms susceptance is defined as the reciprocal of reactance and the imaginary part of the complex representation of admittance suscept ibility conduct ance Susceptibility In the use of Lake Shore equipment susceptibility involves subjecting a sample material to a small alternating magnetic field The flux variation due to the sample is picked up by a sensing coil surrounding the sample and the resulting voltage induced in the coil is detected This voltage is directly proportional to the magnetic susceptibility of the sample Glossary A 3 ow r ite at Lake Shore Model 320 Autotuning Temperature Controller User s Manual Temperature A fundamental unit of measurement which describes the kinetic
50. em Units A system in which centimeter gram second units are used for electric and magnetic qualities Greek Alphabet The Greek alphabet is defined as follows Alpha a A lota l I Rho P P Beta B B Kappa K K Sigma O Z Gamma y T Lambda A A Tau T T Delta A Mu u M Upsilon v Y Epsilon e E Nu v N Phi O Zeta C Z Xi E E Chi X X Eta T1 H Omicron o O Psi y Ki Theta 8 e Pi x TI Omega Q Hertz Hz A unit of frequency equal to one cycle per second Hazard Communication Standard HCS The OSHA standard cited in 29 CFR 1910 1200 requiring communication of risks from hazardous substances to workers in regulated facilities international System of Units SI A universal coherent system of units in which the following six units are considered basic meter kilogram second ampere Kelvin degree and candela The MKSA system of units is a constituent part of this system 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 Liquid Helium LHe Used for low temperature and superconductivity research minimum purity 99 998 Boiling point 1 atm 4 2 K Latent heat of vaporization 2 4 Btu liter Liquid density 0 275 Ibs liter EPA Hazard Categories Immediate Acute DOT Label Nonflammable Gas Health and Sudden Release of Pressure Hazards DOT Class Nonflammable Gas DOT Name Helium Refrigerated Liquid DOT ID No UN 1963
51. er polarity or the input option will not operate properly The positive terminal of the terminal block is indicated by the V label on the rear panel and should correspond with the positive thermoelement listed for each type of thermocouple Thermocouple Curve Selection To choose a thermocouple curve 6 through 10 listed in Table 2 2 and refer to the instructions for manual curve selection in Paragraph 2 9 Thermocouple Compensation From Front Panel To determine whether thermocouple compensation is selected or not press the Setup key until the curve selection is shown The display will show on in the right most digits if Thermocouple Compensation is on and off if it is off To toggle the compensation status press the Left or Right cursor key Thermocouple Compensation From Remote Interface To select or prevent thermocouple compensation over the remote interface use the ACOMP command described in Chapter 5 Special Features 4 3 5 4 3 6 4 3 7 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Internal Offset Adjustment When a new or different thermocouple is attached to the instrument it is necessary to adjust the offset to compensate for discrepancies in thermocouple material leads and connections An offset adjustment trimpot is provided to allow offset calibration of the thermocouple The steps below ouiline the procedure 1 Place the thermocouple in a reference bath of known temperature liqui
52. es for Chromel AuFe 0 07 Chromel AuFe 0 03 Chromel CuFe 0 15 E K and T 0 1K 0 1 or better in K or C 0 1 or better in K or C Equivalent to temperature accuracy 25 watts 0 1 A with 25 volts compliance 25 ohm or greater RS 232C Three wire half duplex asynchronous transmission at 300 or 1200 baud Connector is RJ 11 modular socket Inputs Setpoint Heater On Off Curve data Outputs Temperature Setpoint Heater External curve 105mm wide x 132mm high x 280mm deep 4 2in x 5 2in x 11in Net Weight 2 7kg 6 Ibs 90 125 or 210 250 VAC rear panel selectable 65VA Ordering Information To order specify one of the following One Double Banana Plug for heater output 106 009 Input Type Model Silicon Diode 320 01 Optional Accessories Platinum 320 02 2001 RJ11 10ft 3m Modular RS 232 Phone Cord Thermocouple 320 04 2002 RJ11 to DB25 Adaptor Connects RJ11 to RS 232 serial port on rear of computer 8271 20 Sensor Heater Cable Assembly for diode and platinum sensors 106 233 Extra Sensor Input Connector 106 009 Extra Double Banana Plug for heater output Specifications subject to change Rev 1 0690
53. fective reset time constants between 999 seconds and 1 second can be achieved by entering reset settings of 1 999 Reset time in seconds is 999 Value Entered A reset of zero will make the controller proportional only To enter a new reset value press the Setup key until the RESET is shown in the display The display will show the current reset setting Use the Left and Right keys to cursor to the digit to be changed It will flash to indicate that it can be incremented or decremented with the Up or Down key When the reset value is set press the Setup or Scroll key to enter it For example if the Reset setting is 20 the reset time in seconds is approximately 50 999 20 50 Operation Lake Shore Model 320 Autotuning Temperature Controller User s Manual 3 4 3 35 M Rate D This adjusts rate time constant of differentiator D in the control function Effective settings are between 0 seconds and 200 of 1 4 the reset time In manual mode rate is normally set at 1 4 the reset time in seconds 100 because larger values may cause system instability To enter a new rate press the Setup key until RATE is shown in the display The display will show the current rate percentage setting Use the Left and Right keys to cursor to the digit to be changed It will flash to indicate that it can be incremented or decremented with the Up or Down key When the rate value is set press the Setup or Scroll key to enter it ANUALLY SETTING
54. hat particular curve usually 31 but can be up to 99 Y Units The value will be voltage or Requiv Refer to CURV Command The value will have 1 character before the decimal place and 5 after it 0 00000 Z Temperature The value will have 3 places before the decimal point and one after it 000 0 00 STANDARD DRC D N 31 0 00000 499 9 0 19083 365 0 0 24739 345 0 0 36397 305 0 0 42019 285 0 0 47403 265 0 0 53960 240 0 0 59455 220 0 0 73582 170 0 0 54606 130 0 0 95327 090 0 1 00460 070 0 1 04070 055 0 1 07460 040 0 1 09020 034 0 1 09700 032 0 1 10580 030 0 1 11160 029 0 1 11900 028 0 1 13080 027 0 1 14860 026 0 1 07200 025 0 1 25070 023 0 1 35050 021 0 1 63590 017 0 1 76100 015 0 1 90660 013 0 2 11720 009 0 2 53660 003 0 2 59840 001 4 6 55360 000 0 term Remote Operation Lake Shore Model 320 Autotuning Temperature Controller Users Manual CHAPTER 6 SERVICE AND CALIBRATION 6 0 GENERAL 6 1 6 2 6 3 This chapter describes the service and calibration for the Model 320 Temperature Controller Paragraph 6 1 provides general maintenance information Fuse replacement is described in Paragraph 6 2 Line voltage selection is described in Paragraph 6 3 Paragraphs 6 4 thru 6 6 describe calibration for the Model 320 01 02 and 04 respectively GENERAL MAINTENANCE To clean the Model 320 periodically to remove dust grease and other contaminants perform the following 1 Clean front back panel
55. he Serial I O connector is a standard 6 wire RJ 11 telephone jack Lake Shore offers the Model 2002 RJ 11 to 25 pin adapter and the Model 2001 10 ft cable which connects the Model 320 and Model 2002 See Figures 2 3 thru 2 5 for Model 2001 2002 and 2003 wiring information Refer to Section 4 for information on serial interface commands The Model 320 allows for two different BAUD rates 300 and 1200 Press the Setup key repeatedly until the BAUD rate is shown The Up arrow key will toggle between 300 and 1200 BAUD as indicated on the display Model 320 Serial Interface specifications and other information is provided in Chapter 5 RACK MOUNTING The Model 320 can be installed in a standard size 1 4 panel EIA rack space Installation 2 7 Lake Shore Model 320 Autotuning Temperature Controller User s Manual o vw TxD YELLOW Oo w i Gnd GREEN b n Gnd RED to N RxD BLACK N S 320 U 2 3 Figure 2 3 Model 2001 RJ11 Cable Assembly Wiring Details DB9 CONNECTOR NOTUSED RJ11 RECEPTACLE S 320 U 2 4 Figure 2 4 Modei 2003 RJ11 to DB9 Adapter Wiring Details DB25 CONNECTOR NOT USED RJ11 RECEPTACLE 320 U 2 5 Figure 2 5 Model 2002 RJ11 to DB25 Adapter Wiring Detalls 2 8 Installation Lake Shore Model 320 Autotuning Temperature Controller User s Manual CHAPTER 3 OPERATION 3 0 GENERAL This chapter describes Model 320 Temperature Controller operation The front panel contr
56. he tuning selection is shown Now press the Up arrow key until the display shows Auto PI Gain Only The third control algorithm available on the Model 320 is GAIN P only No time dependent control parameters other than digital sampling rate will be initiated by the controller In this mode characteristics of the system being controlled are more apparent but there will be a temperature offset from the setpoint To select the P tuning algorithm press the Setup key until the tuning selection is shown Now press the Up arrow key until the display shows Auto P Special Features 4 1 Lake Shore Model 320 Autotuning Temperature Controller User s Manual 4 2 AUTOTUNING FEATURES The following paragraph on Autotuning features is presented in question and answer format 4 3 4 3 1 4 3 2 4 3 3 4 3 4 Q A The What algorithm or algorithms is Lake Shore using in the Model 320 controller The procedures used to determine values for gain rate and reset took us a long time to implement These procedures are evolving with time and are considered proprietary to the company It is significantly more difficult to determine automatically these control parameters at cryogenic temperatures because of the differences in cryogenic physical plants and their variation with temperature It is not uncommon for a cryogenic load to vary by over three orders of magnitude over its useful temperature range It is also not uncommon for
57. inally devised by Anders Celsius 1701 1744 a Swedish astronomer To convert Fahrenheit to Celsius subtract 32 from F then divide by 1 8 or C F 32 Y 1 8 CGS System of Units A coherent system in which the basic units are the centimeter gram and second 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 Cryostat A low temperature thermostat Decibels dB The standard unit for expressing transmission gain or loss and relative power levels Decibels indicate the ratio of power output to power input dB 20 10910 V1 V2 The term dBm is used when a power of one milliwatt is the reference level 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 Dewar A vacuum bottle used to contain liquid nitrogen and other supercooled gases Fahrenheit F A temperature scale that registers the freezing point of water as 32 F and the boiling point as 212 F under normal atmospheric pressure Originally devised by Gabriel Fahrenheit 1686 1736 a German physicist residing in Holland who developed the use of mercury in thermometry To convert Celsius to Fahrenheit multiply C by 1 8 then add 32 or F 1 8 x C 32 Gaussian Syst
58. itute 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 SAFETY SYMBOLS Product will be marked with this symbol in order to protect against damage to the instrument gt Indicates dangerous voltage terminals fed by voltage over 1000 volts must be so marked i o Protective conductor terminal For protection against electrical shock in case of a fault T Used with field wiring terminals to indicate the terminal which must be connected to ground before operating equipment SR 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 Ae or Frame or chassis terminal A connection to the frame chassis of the equipment which normally includes all exposed metal structures D Alternating current power line Direct current power line Hd Alternating or direct current power line Introduction Lake Shore Model 320 Autotuning Temperature Controller User s Manual CHAPTER 2 INSTALLATION 2 0 GENERAL 2 1 2 2 This chapter provides general installation instructions for the Model 320 Aut
59. l 2 7 SENSOR INPUT CONNECTIONS 2 7 1 Diode and platinum connections are defined in Paragraph 2 7 1 Thermocouple connections are described in Paragraph 2 7 2 Finally thermocouple compensation is discussed in Paragraph 2 7 3 Diode Model 320 01 Platinum Model 320 02 Connections The Model 320 has one rear panel 6 pin input connector for diode Model 320 01 or resistance Model 320 02 sensors The lead connection definition for the sensor is shown in Figure 2 2 and Table 2 1 The use of a four wire connection Figure 2 2 a b is highly recommended for two lead resistive elements and diodes to avoid introducing current resistive IR drops in the voltage sensing pair which translates into a temperature measurement error An alternate two line wiring method Terminals and V shorted together may be used for the DT 470 series diodes in less critical applications where lead resistance is small and small readout errors can be tolerated Figure 2 2 c Measurement errors due to lead resistance for a two lead hook up can be calculated using T IR dV dT where is 10 microamperes R is the total lead resistance dV dT is the diode sensitivity and T is the measurement error For example R 250 with dV dT 2 5 mV K results in a temperature error of 1 kelvin Two wire connections are not recommended for platinum The Lake Shore Quad Lead 36 Gauge Cryogenic wire is ideal for connections to the sensor since the four leads are run toge
60. mV above 2 volts For Thermocouple inputs the millivolt symbol is used to indicate millivolts The millivolt display resolution is 1 microvolt Resistance Resolution Model 320 02 Only The Resistance mode is allowed for the Platinum Input configuration The display resolution in resistance is 0 01 Q below 200 Q and 0 1 Q above 200 Q Control Input Errors If an input signal from the sensor exceeding full scale is applied to the input leads an overload condition is present and is indicated by OL on the display The heater is then shut off If no signal or a signal of the wrong polarity is present at the input leads a Zero Error is indicated by Er27 on the display and the heater is promptly shut off The Model 320 will display dashes on the display if there is an internal malfunction Operation Lake Shore Model 320 Autotuning Temperature Controller User s Manual 3 3 CONTROL FUNDAMENTALS The Model 320 has several outstanding features which will help in temperature control of your cryogenic system These include standard built in curves along with the ability to store a 99 point curve Serial Interface an isolated current source allowing true four wire sensor readings eight character alphanumeric display for high visibility simple scroll type input with cursor key entry 25 Watt DC current source output with short circuit protection of the output and digital filtering These and other features are discussed i
61. n 0 19083 365 0 input the command as follows ECUR11 0 19083 365 0 term The Model 320 will recognize the units field and replace that data point with the new temperature value KCU R1 1 Delete User Curve 11 Data Command input KCUR11 Returned Nothing Remarks Will delete all data stored for the User Curve 11 5 10 Remote Operation Lake Shore Model 320 Autotuning Temperature Controller User s Manual Curve Commands Continued CURV11 Input Returned Remarks Remote Operation iu Rp Thermocouple Millivolts Enter User Curve CURV11 XXXXXXXXXXXXXXXXXX YY Nothing Enters the user curve where X 18 characters for curve description must be at least 1 character Y unit temperature data point in ascending units must be from 2 to 97 pairs and the character is at the end of the data string The data points are input with the units value first This value will be voltage or Requiv The value will have one character before the decimal place and five after it 0 00000 The table below gives the conversion of raw units into the format required The Model 320 automatically fills in leading and trailing zeros The second value is the temperature lt has three character spaces before the decimal point and one after it 000 0 After all points are input placement of an x terminates the sensor curve input Silicon Diode Input range is 0 00000 to 6 00000 Input range is 0 00 to
62. n detail throughout this manual In addition the Model 320 along with the Model 330 is the first cryogenic controller with an Autotuning feature The Autotuning algorithm determines the settings of controller gain Proportional reset Integral and rate Differential by observing the time response of the system upon changes in setpoint under either P Pl or PID control Since this is a digital system there are two inherent limitations associated with digital control and Autotuning First there is the limitation that any control system is inherently unstable if the sampling rate frequency is not greater than twice the system bandwidth inverse of system time constant This is known as the Nyquist criterion With the current technology used in this instrument i e sampling frequency etc digital control is possible for cryogenic system with time constants near or greater then one second Fortunately almost all cryogenic system which operate above 1 kelvin will have time constants that meet this criteria The Autotuning function requires that the system time response be measured as a result of a change in temperature setpoint In order to get meaningful data for determining the PID parameters several points on this response curve must be measured Consequently for cryogenic systems where step responses are less than 5 seconds where the number of measured points is small correct determination of the PID parameters is difficult and bette
63. ntrol stability to 0 1 or better in K or C Simple scroll type entry Small 1 4 DIN package Isolated current source allows true 4 wire sensor readings resulting in high instrument accuracy Block Diagram for Diode or Platinum Sensor Input DISPLAY KEYPAD CURRENT SOURCE CONTROLLER EN RS 232 INTERFACE RAM SCH CAU SCH SENSOR CURVE A 7D Lines 2 and 3 represent separate isolated power supplies They allow true 4 wire sensor readings Specifications Display Resolution 0 1 in Kor C Electronic Accuracy 0 1 or better in K or C Temperature Accuracy Electronic accuracy plus sensor accuracy Electronic Temperature Repeatability 0 1 or better in K or C Temperature Range Silicon Diode 1 4K to 475K Platinum 30K to 800K Thermocouple Ch AuFe 0 07 4K to 325K Ch AuFe 0 03 1 4K to 325K Ch CuFe 0 15 4K to 273K E 40K to 425K K 90K to 325K T 90K to 485K Standard Curves Standard curves stored in the unit include Curve DRC D for DT 500 silicon diodes Curve 10 for DT 450 DT 470 and DT 471 silicon diodes DIN Curve 43760 for PT 100 series 100 ohm platinum sensors Temperature Control Set Point Resolution Control Stability Control Repeatability Control Accuracy Heater Output Heater Load Dependent on sensitivity of sensor General Interface Dimensions Weight Power Accessories Su Users Manual One Sensor Input Connector 106 233 oplied Thermocouple curv
64. nual 5 2 3 Control Process Commands This paragraph provides a detailed description of each Control Process Command These commands allow the interface to change any of the control parameters of the Model 320 Manual mode PID parameters are accessible as well as Autotuning status TUNE Input Returned Remarks Sets Autotuning Status TUNE X Nothing Set Autotuning status as follows 0 Manual 1 P 2 Pl and 3 PID Refer to Paragraph 4 1 for further information on Autotuning settings TUNE Input Returned Remarks Autotuning Query TUNE XX Returns current Autotuning status where 0 Manual 1 P 2 Pl and 3 PID Refer to Paragraph 4 1 for further information on Autotuning settings GAIN Input Returned Remarks Example Set Gain While In Manual Control Mode GAIN XXX Nothing The gain parameter can be filled in with an integer of 0 through 999 GAIN65 term instructs the Model 320 to set a control gain of 65 Gain corresponds to the Proportional P portion of the PID Autotuning control algorithm GAIN Input Returned Remarks Gain Query GAIN XXX Returns current gain setting in manual or Autotune mode The value returned is an integer from 000 through 999 Gain corresponds to the Proportional P portion of the PID Autotuning control algorithm RSET Input Returned Remarks Remote Operation Manual Mode Reset Setting RSET XXX Nothing Th
65. of Liquid Hellum to Liquid Nitrogen Boiling Point 1 atm in K Thermal Conductivity Gas wcm 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 A typical cryogenic dewar is shown in Figure B 1 S ACS U E 1 Figure B 1 Typical Cryogenic Storage Dewar Handling LHe amp LN2 B 1 B4 0 B5 0 _ Lake Shore Model 320 Autotuning Temperature Controller User s Manual LIQUID HELIUM AND NITROGEN SAFETY PRECAUTIONS Transferring LHe and LN2 and operation of the storage dewar controls should be in accordance with the manufacturer supplier s instructions During this transfer it is important that all safety precautions written on the storage dewar and recommended by the manufacturer be followed 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
66. ols are described in Paragraph 3 1 Sensor control is described in Paragraph 3 2 Control fundamentals are described in Paragraph 3 3 Manual control settings are described in Paragraph 3 4 Finally manual PID parameter settings are described in Paragraph 3 5 3 1 DEFINITION OF FRONT PANEL CONTROLS This paragraph provides a description of the front panel controls on the Model 320 The three function keys on the Model 320 are labeled Scroll Setup and Heater These keys are used to select display modes or change modes The Cursor keys are used to make changes in adjustable parameters in these particular modes when appropriate Scroll The Scroll key is used to scroll through the most often viewed instrument displays This includes the control sensor reading and setpoint and heater output current O 320 Autotuning Temperature Controller Heater Setup Scroll LJA Co 0 el L EllakeShore O S 320 U 1 1 Figure 3 1 Model 320 Front Panel Operation 3 1 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Front Panel Keypad Definitions Continued 3 2 3 2 1 3 2 2 3 2 3 3 2 Setup The Setup key is used to select setup parameters Each of these parameters can then be configured for individual applications Units curve number Autotuning parameters manual tuning parameters and Baud can be accessed with this key Heater The sole function of the heater key is to turn the heater on and off
67. ommands allow the user to verify existing curves added at the factory or enter and delete the user defined curve over the interface CU D 2 Curve Identification Query input CUID Returned WW XXXXXXXXXXKXXXXXXK Y ZZ Remarks Returns the header lines that identify the curves standard sensor and user curve loaded into each curve location The information lines for the user curve will only be available if it is actually present Information returned is defined as follows W Curve number The value given here will be 00 through 11 X Curve description 18 character information line All 18 character spaces do not have to be used Y Temp coefficient N represents a negative temperature coefficient while P represents a positive one Z Number of points This value will be the number of points for that particular curve usually 31 but can be up to 99 Example 00 STANDARD DRC D N 31 01 STANDARD DRC E1 N 31 02 STANDARD CRV 10 N 31 03 STANDARD DIN PT P 31 etc ECU R1 1 Edit A Data Point In User Curve 11 Input ECUR11 X XXXXX XXX X Returned Nothing Remarks Fill in the point to be edited It should be the units temperature combination If the Model 320 does not recognize either the units value or the temperature value it will assume that you are inputting an entirely new point and place it in the proper ascending position Example If the point to be edited was input as 0 19083 364 0 and should have bee
68. ond this point 1 Locate current adjustment R5 zero adjust R6 and span adjustment R7 on top rear of instrument Side of Unit RS R6 R7 J lo le le ei Top View of Model 320 Adjustment Potentiometers Rear of Unit Measure resistance of RTEST to 4 1 2 places with a 4 lead measurement Write down resistance Attach test connector and put multimeter across RTEST Plug in instrument and place Power switch to on in position Turn heater off Allow unit to warm up for 1 hour Adjust current source with R5 until current through Rresr is 1 mA For a precision 100 Q resistor DMM voltage should read 1 0000 V For a less accurate resistor 100 25 for example DMM voltage should read 1 0025 V 8 Replace 100 2 resistor with a short 9 Adjust R6 until display toggles between 0 00 Q and Err27 10 Replace short with 100 Q resistor 11 Adjust R7 until display reads 100 0 Q For a less accurate resistor refer to example in Step 7 12 Configure unit to display in ohms Refer to Chapter 3 13 Adjust R7 until display reads same as multimeter 0 1 Vdc 14 Place Power switch to off out position 15 Disconnect test connector E E LS Service 6 3 6 6 6 4 Lake Shore Model 320 Autotuning Temperature Controller User s Manual MODEL 320 04 CALIBRATION To calibrate the Model 320 04 requires a Voltage Standard with microvolt resolution and a test connections as follows 4 V Voltage Standard 2
69. ons will result in unstable readings and control For additional information on thermocouple operation refer to Chapter 4 2 7 3 Thermocouple Compensation The thermocouple input has a thermal block for connecting thermocouple wires and for temperature compensation The thermocouple response curve tables within the instrument are normalized to the ice point of water Consequently accurate readings can be obtained by one of two methods An ice bath with a reference junction can be used with the internal room temperature compensation turned OFF The more convenient method is to eliminate the reference junction with its associated ice bath and use the internal electronic room temperature compensation by turning the internal compensation ON 2 8 POWER UP The power up paragraph consists of a power up sequence in Paragraph 2 8 1 power up configuration in Paragraph 2 8 2 and power up errors in Paragraph 2 8 3 2 8 1 Power Up Sequence The following power up Sequence occurs at power up 1 The Display indicates as a test of the display segments oe Se Se GS SE OE A 2 Next the unit displays LSCI 320 3 Then the factory set BAUD rate will show BAUD 300 4 The Model 320 01 then displays or the Model 320 02 then displays or the Model 320 04 then displays 5 The Model 320 then goes into normal operation installation 2 5 2 8 2 2 8 3 2 9 Lake Shore Model 320 Autotuning Temperature Controller User s Manual Power Up
70. otuning Temperature Controller Inspection and unpacking instructions are provided in Paragraph 2 1 Repackaging for shipment instructions are provided in Paragraph 2 2 A definition of rear panel controls is provided in Paragraph 2 3 Finally an initial setup and system checkout procedure is provided in Paragraph 2 4 INSPECTION AND UNPACKING Inspect shipping containers for external damage All claims for damage apparent or concealed or partial loss of shipment must be made in writing to Lake Shore within five 5 days from receipt of goods If damage or loss is apparent please notify the shipping agent immediately Open the shipping containers A packing list is included with the system to simplify checking that the instrument 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 of such filings In case of parts or accessory shortages advise Lake Shore immediately Lake Shore cannot be responsible for any missing parts unless notified within 60 days of shipment The standard Lake Shore Warranty is included on the A Page immediately behind the title page of this manual REPACKAGING FOR SH
71. r User s Manual This Page Intentionally Left Blank Application Notes Lake Shore Model 320 Autotuning Temperature Controller User s Manual ALPHABETICAL INDEX The following is an alphabetical index of the headings and major topics contained in the Lake Shore Model 320 Temperature Controller User s Manual An alphabetical index is different than a page number index the reader is referred directly to a paragraph figure or table number A paragraph number reference is simply a number in the point system 1 1 1 Figure and table numbers are prefaced with an F or T respectively Information in the Appendices is prefaced with the Appendix Letter A1 0 A figure or table reference in an appendix is delineated by a slash e g T A 1 Major topic headings are shown in all capitals with subordinate headings indented and in alphabetical order Paragraph Figure F Subject Table T Number A B ADPICAION NOTOS aida dt A A A D1 0 Automatic Tuning Gain On A A s tas A satin aa 4 1 4 Initial Values of PID Parameters in Autotuning Mode 4 1 1 MINIMUM OVEISNOOL cir a e wees De dati 4 1 2 Minimum Time Ta Satpoint sorsa tinier des ba A d K Ga ada 4 1 3 Aulotuning F alures eege S a sa eds liado 4 2 C Calibration eat A NEEN 6 4 MO B 3202 ira a ai s oe rums WA dw ee eae a cs 6 5 MOQO oda bg Sea A mee 6 6 Comparison of Liquid Helium to Liquid Nitrogen T B 1 Control Fundamentals MOS ir A RS
72. r permits the Model 320 to be connected to 100 120 220 or 240 VAC line voltages Use the following procedure to change the line voltage To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before changing the line voltage selection 1 Open fuse compartment by prying open cover with a small screw driver from right side of assembly 2 Do not rotate voltage selector wheel while it is in place Remove voltage selector wheel and replace it with proper voltage facing out Note that wheel can only be inserted with writing read from left Service 6 1 Lake Shore Model 320 Autotuning Temperature Controller User s Manual 3 Install proper fuse as follows 1 A 3AG Slow Blow fuse for 90 125 VAC or a 0 5 A 3AG Slow Blow fuse for 210 250 VAC 6 4 MODEL 320 01 CALIBRATION To calibrate the Model 320 01 requires a digital multimeter DMM with a 4 1 2 digit display capable of 4 lead resistance measurement and a test connector wired as follows 5 l 4 V Pre ST 100 KQ 2 V 1 1 where Rrest should be nominal 100 KQ and as temperature stable as possible 20 50 ppnv C Line voltage is present inside the box Only qualified personnel should proceed beyond this point 1 Locate current adjustment R5 zero adjustment R6 and span adjustment R7 on top rear of instrument Side of Unit R5 R6 R7 KW lelele e Top View of Model 320 Adjustment Potentiometers Rear of
73. r temperature control will normally be achieved by manual selection of gain and reset rate will not normally be required Fortunately fast cryogenic systems are not difficult to tune manually For slower systems with longer time constants which can be very difficult to tune manually Autotuning can obtain enough information on a step change to characterize the system and determine proper values of gain reset and rate There may be other conditions where you will prefer to stay with manual settings For example when a closed cycle refrigerator has very little mass on its second stage and is near its bottom temperature attempts at Autotuning may give poor results for control settings due to the large inherent temperature fluctuations associated with the cooling cycle Adding mass to the second stage smoothes out these fluctuations but lengthens cooldown time Lake Shore has simplified the input of the rate time constant in this controller to correspond to a percentage of the reset time constant Le 0 to 200 Consequently if you are in the manual mode and you set RATE at 100 on any change in RESET the controller will automatically calculate the RESET time constant 999 RESET and set the RATE time constant at 1 8 of the RESET time constant This is one half the conventional Zeigler Nichols setting for rate and results in a smaller overshoot of a given setpoint Therefore once RATE is set as a percent you do not have to worry about updating
74. rature Controller Paragraph 4 1 describes Automatic tuning Paragraph 4 2 describes Autotuning features Finally Paragraph 4 3 describes Model 320 04 Thermocouple Controller Operation AUTOMATIC TUNING Autotuning is recommended for most control systems There are three control algorithms available that optimize different control requirements To observe which of the three algorithms described below is being used press the Setup key until the tuning selection is shown in the display P Pl PID or Manual Initial Values of PID Parameters In Autotune Mode The initial values of the PID parameters in the Autotune mode are set when the controller is changed from Manual to either P PI or PID control The initial PID factory settings are 50 and 20 with the controller set for PI control Minimum Overshoot The full three function PID control algorithm is designed to minimize overshoot It uses GAIN P RESET I and RATE D to bring the system to the control temperature as smoothly as possible To select the PID tuning algorithm press the Setup key until the tuning selection is shown Now press the Up arrow key until the display shows Auto PID Minimum Time To Setpoint The two function PI control algorithm minimizes the time it takes for the system to first reach the setpoint Some of the damping used in PID control is not present so more overshoot should be expected To select the Pl tuning algorithm press the Setup key until t
75. reset change with temperature In a normal cryogenic system the time response of the system slows down as the temperature increases Consequently as the temperature rises the time constant will become longer as well Therefore if you have determined a valid value of reset at a particular temperature increasing the temperature will result in a decrease in the reset number i e a longer time constant conversely decreasing temperature will demand a shorter time constant i e an increase in the reset setting For a silicon diode sensor why does the optimum controller gain value increase by nearly an order of magnitude between 25 K and 35 K The system gain is a product of the controller gain and the sensor gain i e sensor sensitivity At 25 K the sensor sensitivity dV dT is approximately an order of magnitude larger than it is at 35 K If the load parameters have not changed greatly neither will the system gain Therefore the controller gain must be increased to compensate for the reduction in sensor sensitivity What happens to the system gain as the temperature increases It normally increases Consequently if the sensor sensitivity is relatively constant you can normally increase the controller gain with increasing temperature Operation Lake Shore Model 320 Autotuning Temperature Controller User s Manual CHAPTER 4 SPECIAL FEATURES 4 0 GENERAL 4 1 This chapter describes the special features of the Model 320 Tempe
76. ront panel of Model 320 04 select desired temperature units 15 Turn on thermocouple compensation 16 Adjust offset adjustment trimpot R8 so that displays read reference temperature Service Lake Shore Model 320 Autotuning Temperature Controller User s Manual APPENDIX A GLOSSARY OF TERMINOLOGY Absolute Zero Believed to be the lowest possible temperature the temperature at which molecular motion stops and at which heat is completely gone Defined as 0 K calculated to be 273 15 C or 459 67 F American Standard Code for Information Exchange ACSII A standard code used in data transmission in which 128 numerals letters symbols and special control codes are represented by a 7 bit binary number as follows ios Pp fo Pete eer American Wire Gage AWG Wiring sizes are defined as diameters in inches and millimeters as follows AWG Dia In Da mm AWG Dia In Da mm AWG Dia In Da mm AWG Dia In Dia mm 0 1144 2 906 19 0 0359 0 9116 29 0 0113 0 2859 39 0 00353 0 08969 0 0 1019 2 588 20 0 0338 0 8118 30 0 0100 0 2546 40 0 00314 0 07987 Asphyxlant 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 A baud as a signal element must be at least one complete cycle in length in order to carry
77. s and case with soft cloth dampened with mild detergent and water solution NOTE Do not use aromatic hydrocarbons or chlorinated solvents to clean the Model 320 They may react with the silk screen printing on the back panel 2 Clean surface of printed circuit boards PCBs using clean dry air at low pressure FUSE REPLACEMENT The line fuse is accessible from the rear of the Model 320 without opening the case Use the following procedure to check and or replace the fuse To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before replacing the fuse 1 Set POWER switch to OFF and disconnect power cord from unit Fuse compartment will not open with power cord in place Fuse compartment is located just to right of power cord socket in power connector assembly 2 Open fuse compartment by prying open cover with a small screw driver from right side of assembly 3 Remove lower fuse holder by sliding it out of its position with aid of small screw driver CAUTION For continued protection against fire hazard replace only with the same type and rating of fuse as specified for the line voltage selected 4 Replace fuse as follows 1 A 3AG Slow Blow fuse for 90 125 VAC or a 0 5 A 3AG Slow Blow fuse for 210 250 VAC 5 Replace fuse holder in lower fuse position close fuse compartment and connect power cord LINE VOLTAGE SELECTION The rear panel three pronged line power connecto
78. s 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 Modify Instrument Because of the danger of introducing additional hazards do not install subst
79. s sent 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 A leading is not required but a leading is required If you enter a correctly spelled command without a the command will send all zeros Incorrectly spelled commands are ignored 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 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 Model 320 Remote Operation 5 3 Lake Shore Model 320 Autotuning Temperature Controller User s Manual 5 2 SERIAL INTERFACE COMMAND SUMMARY This paragraph provides a summary of the Serial Interface Commands The summary is divided into four command groups Display Channel Control Process and Curve Commands A detailed list of Display Commands is provided in Paragraph 5 2 1 A detailed list of Channel Commands is provided in Paragraph 5 2 2 A detailed list of Control Process Commands is provided in Paragraph 5 2 3 A detailed list of Channel Commands is provided in Paragraph 5 2 2 A detailed list of Curve Commands is provided in Paragraph 5 2 4 The commands are presented in the same order as shown below Available command formats are as follows XXX Command Only XXX
80. s to an accuracy which exceeds 50 mK over the entire temperature range of the Precision Option Therefore the overall system accuracy and that of the calibration itself is reduced to a minimum Lake Shore calibrations are typically better than 50 mK below 28K for diode sensors See the Lake Shore Product Catalog for additional discussion of calibration accuracy Memory The memory space provided in the Model 320 allows one user response curve to be stored in _ the instrument The data for calibrated sensors can be stored in the instrument as an 8001 Precision Option at the factory or by the customer via the Serial interface There is room for a 99 point curve Control Algorithm The Model 320 offers a simple and inexpensive answer to control needs The control algorithm provides three term digital temperature control Proportional GAIN integral RESET and derivative RATE are individually set via front panel entry in manual mode or automatically tuned with the Autotune feature O 320 Autotuning Temperature Controller Heater Setup Scroll TEA C Power K C EllakeShore O S 320 U 1 1 Figure 1 1 Model 320 Temperature Controller Front Panel introduction Lake Shore Model 320 Autotuning Temperature Controlier User s Manual Control Setpoint The control setpoint is set via the front panel keypad or over the computer interface The setpoint can be set in temperature to a resolution of 0 1 K or C Heater Power Outpu
81. ssary to select the response curve that matches the sensor being used To determine which curve is selected press the Setup key repeatedly until the curve number is displayed An example of what the display may show is displayed below Cu 04 To change the curve press the Up cursor key to increment or the Down cursor key to decrement the display The curve numbers available are O through 11 The standard curves with their curve number and temperature range are given in Table 2 2 If a curve with the wrong temperature coefficient slope is selected the Model 320 will default to the lowest order curve of the correct type In addition to the standard curves Table 2 2 allows room for one user defined curve This is curve 11 The user defined curve can have up to 97 points plus two end points These are put into the curve table at the factory or by the user over the remote serial interface Chapter 5 of this manual describes entry over the serial interface When in the curve selection mode the Left and Right cursor keys are used on the Model 320 04 thermocouple controller to toggle compensation on and off Installation Lake Shore Model 320 Autotuning Temperature Controller User s Manual 2 10 2 11 2 12 Table 2 2 Sensor Curves Curve No Number ofLines_ Range K Description______ DT 500 DRC Curve D DT 500 DRC Curve El DT 400 Series Sensors Curve 10 Platinum DIN Curve DT 400 Series Sensors Curve 10 Reserved
82. stem being controlled would result in a stable set point in a time frame between 5 and 10 minutes How do determine RESET The oscillation period which you measured in determining the appropriate gain setting is equal to the reset time constant which is desired Divide this number in seconds into 1000 and set the result into the RESET register This result is the number of repeats per 1000 seconds If the system did not oscillate at the highest gain setting use the following procedure Stabilize the temperature at a high gain setting Change the set point downward by one or two degrees and observe the time that it takes for the temperature to change 60 of this excursion Use this number as the reset time constant divide it into 1000 and set in the result as the RESET value What about RATE The rate time constant should normally be somewhere between 1 4 and 1 8 the reset time constant if itis used at all Consequently you can set it between 0 and 200 of 1 4 the reset time constant Start with settings of either 0 50 or 100 and determine which setting gives you the type of control which you desire Don t be surprised if for your system the setting you prefer is O OFF Note that by using a percent of reset time constant rate scales automatically with changes in the reset value and does not have to be revisited frequently Operation 3 5 H Lake Shore Model 320 Autotuning Temperature Controller User s Manual How does
83. t Heater power output of the Model 320 Temperature Controller is a variable DC current source for quiet stable control It sources a maximum of 25 watts with a 25Q heater The heater display is in percentage of full scale output current Thus the user can conveniently monitor heater power applied to the system This value is calculated in the Model 320 and is not an actual measurement Interface A serial interface is standard in the Model 320 It can be used to remotely control most front panel functions and output display data and instrument status 1 2 HARDWARE OPTIONS AND ACCESSORIES The options installed in your unit are detailed on the B page of this manual following the title page A general list of Model 320 options and accessories is detailed in this paragraph The standard Model 320 heater output is 25 watts Model Inputs 320 01 Silicon Diode 320 02 Platinum RTD 320 04 Thermocouple AC Line requirement should be specified at time of order 100 120 220 or 240 VAC 50 or 60 Hz Accessories Included 1 Detachable 120 VAC line cord 115 006 1 Sensor mating connectors 106 233 1 Heater output connector 106 009 1 Users manual MAN 320 Precision Options 8001 Precision option requires calibrated sensor 8002 05 Precision option number if the user already owns a Model 320 Accessories Available 2001 RJ11 3 meter 10 feet Modular RS 232C Phone Cord 2002 RJ11 to DB25 Adapter Connects RJ11 to a 25 pin RS
84. ta H Lake Shore Model 320 Autotuning Temperature Controller User s Manual 5 2 2 Channel Commands This paragraph provides a detailed description of each Channel Command Channel commands set and verify parameters associated with the sensor input channels ACUR Input Returned Remarks ACUR Input Returned Remarks Assign Curve Number ACUR XX Nothing Fill in curve parameter with an integer from 0 through 11 11 for the user curve Refer to Table 2 2 for a listing of sensor curve numbers Curve Number Query ACUR xx Value returned is an integer from 00 through 11 corresponding to the currently selected sensor curve number Refer to Table 2 2 for a listing of sensor curve numbers ACOMP Set Room Temperature Compensation Model 320 04 thermocouple controller only Input ACOMP 0 Or ACOMP 1 Returned Nothing Remarks Select temperature compensation parameter with 0 for off or 1 for on ACOM P Room Temp Compensation Query Model 320 04 thermocouple controller only Input ACOMP Returned 0or1 Remarks Returns current room temperature compensation status where 0 off and 1 on ATYP E Input Type Query Input ATYPE Returned SI PT TC Or ER Remarks Returns input type where SI silicon diode PT platinum TC thermocouple and ER improper switch setting error 5 6 Remote Operation __ Lake Shore Model 320 Autotuning Temperature Controller User s Ma
85. ther and color coded The wire is Phosphor Bronze with a Formvar insulation and Polyvinyl Butryral bonding between the four leads Color coding is red green clear and blue on the four leads which makes it extremely easy to determine one wire from another For this and other accessories refer to the Lake Shore Cryogenic Accessories Catalog Table 2 1 Diode or Platinum Input Connections Current Voltage Current 1 mA platinum Voltage Current 10 mA diodes Shield 5 1 gt 4 V d 2 V J 1 d a 2 Lead Sensor 3 P 4 V 2 V I 1 4 lt __ b 2 Lead Sensor a 4 V 2 V ee D i c 2 Lead Sensor 4 lead Hook up 4 lead Hook up 2 lead Hook up for Diodes for Resistors for Diodes X 320 U 2 2 Figure 2 2 Sensor Connections Installation Lake Shore Model 320 Autotuning Temperature Controller User s Manual 2 7 2 Thermocouple Model 320 04 Connection CAUTION Use care during installation of thermocouple sensor to maintain an isolated ground from the sensor back to the instrument A shorted thermocouple sensor will produce a degraded signal or even no signal at all The thermocouple input has a thermal block for connecting thermocouple wires The positive and negative terminals correspond to V and V and should match the polarity of the thermocouple used Be sure to tighten the screw terminals carefully Loose connecti
86. utput Connectors CAUTION Verify that the AC Line Voltage Selection Wheel located on the rear panel of the Model 320 is set to the available AC line voltage and that the proper fuse is installed before inserting the power cord and turning on the instrument Power and Fuse Assembly The power and fuse assembly is the primary entry and control point for AC power to the unit The assembly consists of two parts power line jack and the fuse drawer The line cord is connected to the power line jack Power to the unit is controlled by the Power switch located on the front panel The fuse drawer contains a 1 A 3AG Slow Blow fuse for 90 125 VAC or a 0 5 A 3AG Slow Blow fuse for 210 250 VAC Serial UO Connector The Serial I O Input Output Connector accepts the standard RJ 11 telephone connector RJ 11 to DB9 or DB25 Adapters are available from Lake Shore that permit connection to the users computer Sensor Input Connector A sensor input connector is provided for attaching temperature sensor to the unit Always turn off the instrument before connecting the sensor Heater Connectors Two banana jacks provide heater connections Installation 2 4 2 5 2 6 Lake Shore Model 320 Autotuning Temperature Controller User s Manual ENVIRONMENTAL REQUIREMENTS The Model 320 is for laboratory use In order to meet and maintain specifications the Model 320 should be operated at an ambient temperature range of 18 28 C The unit may be operate

Model 320 - Lake Shore Cryotronics, Inc.

Contents

Download Pdf Manuals

Related Search

Related Contents