MODEL 8000 OPTION DISK STORAGE OF SENSOR CALIBRATION DATA FILE DESCRIPTION: TEXT DOCUMENT FORMAT The Model 8000 consists of disk storage of calibration data for the Lake Shore Cryotronics, Inc. temperature sensors. For each sensor there are three calibration files containing the test data, the coefficients for a data fit, and an interpolation table. There are also instrument files containing the necessary data to insert the calibration directly into a Lake Shore instrument using LSCurves.exe which is also included on this disk. The exact combination of files contained on this disk depends upon the temperature sensor type and model. The following table lists the files included for each sensor type. A description of each file type follows. IMPORTANT NOTE: While the accuracy of the calibration is at best on the order of several millikelvin, all test data are reported to double precision within the electronic files to allow the user to duplicate the curve fitting and numerical results performed by Lake Shore. This DOES NOT imply that the accuracy or resolution is measured to fifteen digits. Sensor Type Calibration Files Instrument Files ============= ======================== ================ Cernox Test data list 91C Germanium Chebychev polynomial fit 34A Carbon Glass Interpolation Table 330 Thermox 340 Rox 234 ------------- ------------------------ ------------------ Platinum Test data list 91C Rhodium-Iron Chebychev polynomial fit 34A Interpolation Table 330 340 ------------- ------------------------ ------------------ Silicon Diode Test data list 91C Chebychev polynomial fit 34A Interpolation Table 330 340 ------------- ------------------------ ------------------ GaAlAs Diode Test data list 91C Cubic Spline Data fit 34A Interpolation Table 330 340 ------------- ------------------------ ------------------ CALIBRATION FILE DESCRIPTIONS All these files are in ASCII format, where SerialNumber is the serial number of the sensor. -------------------------------------------- The test data file (SerialNumber.DAT): This file contains measurements of resistance or voltage and the corresponding temperatures. The format for resistors is: ============== Temperature (K) Resistance (ohms) D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY . . . . . . ============== The format for diodes is: ============== Temperature (K) Voltage (volts) D.DDDDDDDDDDDDDDESYY D.DDDDDDD D.DDDDDDDDDDDDDDESYY D.DDDDDDD . . . . . . ============== where "D" is a numeric digit "." is the decimal point "E" indicates exponential format "S" indicates the sign of the exponent ("+" or "-") and "YY" a two digit exponent. There are three spaces between the two numbers. -------------------------------------------- The coefficient file (SerialNumber.COF): This file contains the Chebychev polynomial coefficients for a curve fit allowing the user to transform sensor voltage or resistance measurements into their equivalent temperature. Consult the Calibration Report Description for information regarding converting resistances or voltages to temperature using the Chebychev polynomial and coefficients. The electronic file contains a label for each entry identifying it use for the fit. Standard fits are performed either as temperature versus voltage (diodes), temperature versus resistance, or temperature versus LOG10(resistance) depending upon the shape of the characteristic as a function of temperature. The following is an example coefficient file for a platinum sensor: ============== Number of fit ranges: 2 Fit range: 1 Fit type for range: LOG Order of fit range 1: 9 Zlower for fit range 1: -5.20725516305026E-01 Zupper for fit range 1: 1.61631713297016E+00 Lower limit for fit range 1: 0.4289 Upper limit for fit range 1: 32.8444 C(0) Equation 1: 5.35472104488059E+01 C(1) Equation 1: 4.84343274320430E+01 C(2) Equation 1: 1.78731249180996E+01 C(3) Equation 1: 6.71910632694103E+00 C(4) Equation 1: 2.24957224549801E+00 C(5) Equation 1: 6.83864572708680E-01 C(6) Equation 1: 1.64705729725070E-01 C(7) Equation 1: 2.77035831899347E-02 C(8) Equation 1: 8.54503010777701E-04 C(9) Equation 1: -3.20164326544564E-03 FIT RANGE: 2 Fit type for range 2: LIN Order of fit range 2: 5 Zlower for fit range 2: 2.632490364723370E+01 Zupper for fit range 2: 1.280000000000000E+02 Lower limit for fit range 2: 32.8444 Upper limit for fit range 2: 124.4599 C(0) Equation 1: 2.178061368696580E+02 C(1) Equation 1: 1.248272296845860E+02 C(2) Equation 1: 1.516717512664060E+00 C(3) Equation 1: -0.123110200579409E-01 C(4) Equation 1: 3.970264241545280E-02 C(5) Equation 1: -1.341884049509500E-03 ============== The calibration report for each sensor and the accompanying sheet "Calibration Report Description" give a complete description of these parameters and how to use them. -------------------------------------------- The interpolation table file (SerialNumber.TBL): A table yielding resistance or voltage at predefined temperatures is generated using a cubic spline curve fitting routine. In this file, each data record consists of a temperature in Kelvin, the corresponding resistance in Ohms (for resistors) or Voltage (for diodes) in volts, the corresponding sensitivity (dR/dT or dV/dT) in ohms/kelvin (for resistors) or millivolts/kelvin (for diodes). Additionally, the dimensionless sensitivity Sd=(T/R)(dR/dT)=d(logR)/d(logT) is included for resistors. The format for resistors is: ============== Temp Resistance Sensitivity Dimensionless (K) (ohms) (ohms/kelvin) Sensitivity DDD.DDD SD.DDDDDDDDDDDDDDDESYY SD.DDDDDESYY SD.DDDDESYY DDD.DDD SD.DDDDDDDDDDDDDDDESYY SD.DDDDDESYY SD.DDDDESYY DDD.DDD SD.DDDDDDDDDDDDDDDESYY SD.DDDDDESYY SD.DDDDESYY . . . . . . . . . . . . ============== The format for resistors is: ============== Temp Voltage Sensitivity (K) (volts) (millivolts/kelvin) DDD.DDD D.DDDDDDD SDDDD.DDDDDESYY DDD.DDD D.DDDDDDD SDDDD.DDDDDESYY DDD.DDD D.DDDDDDD SDDDD.DDDDDESYY . . . . . . . . . ============== where "D" is a numeric digit "." is the decimal point "E" indicates exponential format "S" indicates the sign of the exponent ("-" or blank for "+") and "YY" a two digit exponent. There are three spaces between the numbers. -------------------------------------------- The cubic Spline file (SerialNumber.SPL): Each data record contains a temperature in Kelvin and the corresponding resistance in ohms or voltage (for diodes), and the curvature in the following format: The format for resistors is: ============== Temperature Resistance Curvature (Kelvin) (Ohms) (Kelvin/ohm/ohm) D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY SD.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY SD.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY SD.DDDDDDDDDDDDDDESYY . . . . . . . . ============== The format for diodes is: ============== Temperature Voltage Curvature (Kelvin) (Volts) (Kelvin/Volt/Volt) D.DDDDDDDDDDDDDDESYY D.DDDDDDD SD.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDD SD.DDDDDDDDDDDDDDESYY D.DDDDDDDDDDDDDDESYY D.DDDDDDD SD.DDDDDDDDDDDDDDESYY . . . . . . . . . ============== where "D" is a numeric digit "." is the decimal point "E" indicates exponential format "S" indicates the sign of the exponent ("+" or "-") and "YY" a two digit exponent. There are three spaces between the two numbers. CALCURVE FILE DESCRIPTIONS FOR USE WITH LSCI INSTRUMENTS ----------------------------------------------------------- The 330 CalCurve file (SerialNumber.330): The .330 file is a readable listing of the temperature-sensor units pairs to be programmed into a Lake Shore instrument such as the Model 330, 91C or 93C. The following is an example of this file. ============== Sensor Model: MODEL Serial Number: SerialNumber Interpolation Method: Straight Line SetPoint Limit: 325 (Kelvin) Data Format: 2 (Volts/Kelvin) Number of BreakPoints: 81 No. Units Temperature (K) 1 0.82640 325.0 2 0.85510 315.0 3 0.92646 290.0 4 0.95472 280.0 . . . . . . . . . ============== ----------------------------------------------------------- The 91C CalCurve file (SerialNumber.91C): The 91C file is the actual temperature-sensor units data string to be programmed into a Lake Shore instrument such as the Model 330, 91C, or 93C. The following is an example of the 91C format (note: hard returns have been added for clarity; this is normally a one line character string): ============== XC06,S00MODELXXXXXX, 0.09032,475.0,0.12536,460.0,0.18696,435.0,0.29959,390.0, 0.42238,340.0,0.45613,325.0,0.49252,310.0,0.54084,290.0, 0.58890,270.0,0.63669,250.0,0.67228,235.0,0.70762,220.0, 0.74266,205.0,0.77736,190.0,0.80028,180.0,0.82303,170.0, 0.84557,160.0,0.85675,155.0,0.86789,150.0,0.87896,145.0, 0.88996,140.0,0.90089,135.0,0.91175,130.0,0.92252,125.0, 0.93321,120.0,0.94380,115.0,0.95431,110.0,0.96471,105.0, 0.97500,100.0,0.98516,095.0,0.99519,090.0,1.00509,085.0, 1.01483,080.0,1.02443,075.0,1.03387,070.0,1.04316,065.0, 1.05231,060.0,1.05954,056.0,1.07019,050.0,1.08402,042.0, 1.08919,039.0,1.09274,037.0,1.09641,035.0,1.09832,034.0, 1.10028,033.0,1.10232,032.0,1.10446,031.0,1.10674,030.0, 1.10918,029.0,1.11187,028.0,1.11494,027.0,1.11870,026.0, 1.12423,025.0,1.13510,024.0,1.15427,023.0,1.17550,022.0, 1.19466,021.0,1.22977,019.0,1.25575,017.5,1.28303,016.0, 1.31194,014.5,1.34351,013.0,1.36678,012.0,1.39194,011.0, 1.41972,010.0,1.45075,009.0,1.48553,008.0,1.52378,007.0, 1.59564,005.2,1.63287,004.2,1.65973,003.4,1.68045,002.7, 1.69299,002.2,1.70105,001.8,1.70570,001.5,1.70697,001.4* ============== ----------------------------------------------------------- The 340 CalCurve files (SerialNumber.340) and (SerialNumber.34A): The .34A file is a data file to be programmed into a Lake Shore instrument such as the Model 340 or 218. The .340 file is a readable listing of the information contained in the .34A file. An example of the 340 format: ============== Sensor Model: SensorModel Serial Number: SerialNumber Data Format: 2 (Volts/Kelvin) SetPoint Limit: 325. (Kelvin) Temperature coefficient: 1 (Negative) Number of Breakpoints: 28 No. Units Temperature (K) 1 .464429 325.000 2 .507562 307.000 3 .552900 288.000 4 .600367 268.000 . . . . . . . . . ============== An example of the 34A format: ============== Name: SensorModel Serial number: SerialNumber Format: 4 ; Log Ohms/Kelvin Limit: 100.00 Coefficient: 1 ; Negative Point 1: 1.87808,100.0 Point 2: 1.88572,97.0 Point 3: 1.89222,94.5 Point 4: 1.89886,92.0 Point 5: 1.90566,89.5 . . . . . . ============== ----------------------------------------------------------- The 234 CalCurve files (SerialNumber.234): The .234 file is a data file with resistance/temperature points formatted for the LSCI Model 234 transmitter. The first entry in the file is the sensor serial number. Each subsequent data record consists of LOG10(resistance) - temperature data pairs. An example of the 234 format: ============== SerialNumber 0.00,325.000 0.02,325.000 0.04,325.000 0.60, 44.422 0.62, 43.194 . . . . . . ============== ----------------------------------------------------------- All CalCurve Files can be loaded into the appropriate instrument using the provided LSCURVES software. Please see lscurves.txt for more details regarding using the software.