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15

Lead resistance errors are compensated for in 3-wire configurations.
However full compensation requires equal resistance in each lead. This
configuration is common with 100-ohm RTDs.

In 4-wire configurations, accuracy is unaffected by lead resistance, and
resistance differences between leads.

NOTE: These instruments measure input voltages on all 4 termi-
nals, and are able to distinguish between 2-4 and 3-wire hookups.
Switching between these measurement modes is automatic.

2. Set instrument to METER mode.

3. Use the sensor-select key to set the instrument to the appropriate func-

tion and range.

NOTE: Due to limited display area, 100

and 1000

RTD's are

indicated on the display by a momentary readout of "RTD-100"
(or "RTD-1000") when first selected.

Thermistors are identified by a momentary alpha-numeric readout
of "Y-400" (signifying YSI Series-400 type thermistor).

Any of these readouts can be recalled by turning the unit off and
back on.

5. DATA LOGGING AND RECALL

Operating as a meter, the unit can save and recall up to 10 readings (each
with independent parameters: eg. °F/°C, TC-type and resolution) in random
access memory.

Figure 6. 4-Wire Resistance Measurement

WHT

BLK

GRN

RED

Summary of Contents for 24

Page 1: ...http www omega com e mail info omega com User sGuide CL23A 24 25 26 27 Digital Calibrator Thermometer ...

Page 2: ...ree in France 0800 4 06342 e mail france omega com Germany Austria Daimlerstrasse 26 D 75392 Deckenpfronn Germany Tel 49 07056 3017 FAX 49 07056 8540 Toll Free in Germany 0130 11 21 66 e mail germany omega com United Kingdom 25 Swannington Road P O Box 7 Omega Drive ISO 9002 Certified Broughton Astley Leicestershire Irlam Manchester LE9 6TU England M44 5EX England Tel 44 1455 285520 Tel 44 161 777...

Page 3: ...Error Messages 11 12 Initial Turn On 11 3 Meter Mode Operation Thermocouple 13 14 Meter Mode Operation RTD Thermistor Ohms 14 15 Data Logging Recall 15 16 Calibrator Mode Operation Thermocouples 17 17 Calibrator Mode Operation RTD Thermistor Ohms 18 18 Storage and Recall of Calibrator Settings 20 9 Step Function 22 10 Ramp Function 22 Service Information 23 11 Calibration Procedures 23 12 Calibrat...

Page 4: ...E Miniature TC jack RTD OHMS THERMISTOR T series instrumentation connector THERMOCOUPLE TYPES K J T E N B R S G C D RTD TYPES 1100Ω platinum 0 00385 1000Ω platinum 0 00385 THERMISTOR TYPE 2252Ω YSI Series 400 RANGES RTK 200 C to 1372 C 328 F to 2502 F RTJ 210 C to 760 C 346 F to 1400 F RTT 200 C to 400 C 328 F to 752 F RTE 230 C to 1000 C 382 F to 1832 F RTN 200 C to 1300 C 328 F to 2372 F RTB 500...

Page 5: ...C and 28 C to 50 C K J T E N 0 002 rdg 0 03 C C B R S G C D 0 002 rdg 0 1 C C RTD THERMISTOR OHMS 0 002 rdg 0 004 rng C METER MODE INPUT CURRENT THERMOCOUPLES 50nA typ METER MODE READING RATE 1 reading second typ METER MODE EXCITATION CURRENTS 100Ω RTD 2mA 1000ΩRTD 200µA 999 99Ω 2mA 9999 9Ω 200µA 99999Ω 50µA THERMISTOR T 113 F 50µA T 113 F 2mA CALIBRATOR MODE OUTPUT LOAD THERMOCOUPLES 500Ω min CAL...

Page 6: ...r Type F C Scale 0 1 1 Resolution Calibrator Meter Mode Memory Contents data storage and ramp parameters DIAGNOSTICS Display codes indicate following conditions BAT Low Battery OPEN Open Input Thermocouple RTD or Thermistor E 1 momentary Invalid Keypad Entry E 2 momentary Ramp Function Not Installed HI Temperature Reading or Keypad Entry Exceeds Rating LO Temperature Reading or Keypad Entry Too Lo...

Page 7: ...to 18 C and 28 C to 50 C less than 0 006 rdg 0 03 C C RAMP FUNCTION Not Included BATTERY LIFE CONTINUOUS 16 hrs typical alkaline 4 hrs typical Ni Cd rechargeable MODEL CL24 SENSOR SELECTION K J T E Thermocouples ACCURACY 18 C to 28 C ambient 2 years 0 5 F rdg 50 F 0 04 rdg rdg 1250 F 1 0 F rdg 50 F TEMPERATURE COEFFICIENT 18 C to 28 C included in accuracy specifications From 0 C to 18 C and 28 C t...

Page 8: ... Up to 11 thermocouple types 2 RTD types and thermistor 1 or 0 1 resolution over temperature range of each sensor F and C scales Reading hold mode 10 memory locations for saving meter readings and or calibrator outputs Step mode for quick sequential recall of calibrator outputs from memory Manual automatic ramping for testing controller setpoints Conforms to ITS 90 thermocouple tables Dust proof s...

Page 9: ... in the event reshipment is necessary Make sure that you have the following items in the packing box 1 CL20 Series Calibrator and Holster 1 Operator s Manual 1 NIST Certificate 1 Accessories Kit SAFETY INFORMATION SAFETY SYMBOLS AND TERMS The symbol on the instrument denotes that the user should refer to the operating instructions The WARNING used in this manual explains dangers that could result ...

Page 10: ...r 42V peak AC Do not use this instrument where voltages at the measurement sur face exceed these levels WARNING Do not substitute a metal part for the nylon screw in the rear case Doing so will degrade electrical isolation of the case WARNING The battery is accessible through a cover on the back of the instrument To avoid electrical shock hazard disconnect all temperature probes and sensors and tu...

Page 11: ... i e electrically isolated probe at the thermometer input BATTERY INSTALLATION REPLACEMENT A 9V alkaline battery is supplied with the instrument but not installed Read the following installation instructions before attempting to install or remove the battery Replacement batteries should also be alkaline types WARNING Turn the unit off and disconnect any input output connec tions before replacing t...

Page 12: ...period microcomputer initialization is per formed MEMORY BACKUP During battery replacement the contents of user programmed memory data operating modes etc can be saved Prior to removing the old battery turn off the instrument and connect an HH22 AC battery charger Then exchange batteries and disconnect the battery charger Do not leave the bat tery charger connected to instruments with non recharge...

Page 13: ... for input instructions Display reads E2 momentarily 1 Attempt made to activate non installed ramp function NOTE RAMP Function enabled on Models CL25 and CL27 only Display reads HI 1 Meter mode input temperature exceeds rating of selected sensor 2 Calibrator mode keypad entry exceeds rating of sensor type Display reads LO 1 Meter mode input temperature too low for accurate measurement 2 Calibrator...

Page 14: ...ry is installed it will automatically default to the METER mode ie temperature measurement operation It also defaults to K type thermocouples and F readings with 0 1 resolution The corresponding LCD annunciators are enabled 12 Figure 3 Display Test Figure 2 Keypad ...

Page 15: ...lowing the power up LCD test If it does not turn off less than 10 of battery remains Refer to Battery Installation Replacement instructions 3 If the meter is already in the METER mode the METER annunciator will be on Otherwise the calibrator mode is enabled and the CALIB annunci ator is on Depress the METER key to return to meter mode 4 Connect an input thermocouple TC to connector T2 Select the a...

Page 16: ...e reading is frozen and all keys except ON OFF and HOLD are locked out Depress the HOLD key again to return to real time readings and re enable the keypad 4 METER MODE OPERATION RTD Thermistor Ohms Set Up 1 Connect a sensor or unknown resistance to the instrument as shown in Figures 4 5 or 6 The 2 wire configuration is simplest but includes lead wire resistance in the measurement 2 wire measuremen...

Page 17: ...rument to METER mode 3 Use the sensor select key to set the instrument to the appropriate func tion and range NOTE Due to limited display area 100Ω and 1000Ω RTD s are indicated on the display by a momentary readout of RTD 100 or RTD 1000 when first selected Thermistors are identified by a momentary alpha numeric readout of Y 400 signifying YSI Series 400 type thermistor Any of these readouts can ...

Page 18: ...in memory When data is stored in a location already filed with data the new data replaces the old Stored readings are retained during power off To Recall Readings 1 While in the METER OPR mode readings stored earlier can be displayed by first depressing the RECALL key Note that the OPR annunciator is replaced by RCL and all memory location annunciators are blanked 2 Next depress the keypad number ...

Page 19: ...IBRATOR MODE OPERATION Thermocouples Set Up 1 Turn on the instrument by depressing the ON OFF key 2 Check that the BAT annunciator turns off after display check If not refer to Battery Installation Replacement instructions 3 When operating as a calibrator the display indicates CALIB Should the instrument be in the METER mode hit the CALIB key to change to the cal ibrator function 4 Select the ther...

Page 20: ...eyond the span of the selected TC type will cause a corresponding error code to be displayed To enter negative ie minus temperatures hit the 0 key first when in the NUM mode The first hit on this key enters the neg ative sign Subsequent hits enter zeros To correct a numeric entry while in the NUM mode hit the CHANGE ENTER key twice This will return number entry to the beginning of a new number To ...

Page 21: ...e Simulation 19 Figure 8 2 Wire Resistance Simulation Figure 9 3 Wire Resistance Simulation GRN RED BLK WHT NOTE Colors indicated apply to Model 84937 Calibration Cable mA current source Calibrator out Thermometer in I out V out ...

Page 22: ... reading of 0 just hit the CLEAR while in the CALIB OPR mode Then depress STORE and a location number 20 1 The same performance tradeoffs apply to 2 3 and 4 wire simulations as to 2 3 and 4 wire measurements Refer to RTD Thermistor and Ohms Meter Mode section above for wiring guidelines 2 Set instrument to CALIBRATOR mode 3 Use the sensor select key to set the instrument to the appropriate func ti...

Page 23: ...ECALL 9 eg etc 4 To return the unit to the CALIB OPR mode after recalling the last set up hit the OPR key NOTES Any other key except ON OFF and CLEAR will also return the OPR mode Set ups recalled from unused locations will display and output 0 Calibrator set ups can be recalled even when the unit is func tioning in the meter mode The same 10 storage locations are shared in both meter and calibrat...

Page 24: ...ing A second hit to the RAMP key starts automatic ramping A third hit turns off the RAMP function User definable RAMP memory locations 1 2 3 4 are dedicated to storage of RAMP parameters step size staircase starting point upper limit and lower limit respectively These memory locations are accessible only when in RAMP prog mode and are independent of the other 10 memory locations Numeric values for...

Page 25: ...valent 3 Calibration cables per Figures 11 12 13 NOTE The copper constantan cables used in Figures 12 and 13 need to be calibrated Voltage errors in these cables should be com pensated at the simulator 4 Calibration cover OMEGA 820 307 4 Ambient Conditions Units should be calibrated at an ambient temperature of 23 C 1 C with rel ative humidity less than 80 Preparation for Calibration 11 Remove bat...

Page 26: ...ed in EEPROM It also indicates that cold junction com pensation is disabled Flashing Ω indicates that error corrections for the cold junction sensors can be stored or recalled from EEPROM 11 Clear the EEPROM locations used to store E1 meter cold junction sen sor error and E2 calibrator cold junction sensor error as follows a Set U U T to CALIB OPR K F mode b Key in CHANGE 0 0 ENTER STO 1 OPR E1 is...

Page 27: ...onfigure calibration set up per Figure 12 Allow 2 3 minutes for ther mal stabilization 11 Calculate E1 as follows E1 U U T Reading 32 0 12 Set U U T to CALIB OPR T F mode 13 Store E1 CHANGE E1 value ENTER STO 1 OPR 14 Go to METER mode and verify U U T reading of 32 0 0 1 F 15 Reconfigure calibration setup per Figure 12 Leave simulator output at 32 F Type T ALLOY mode Allow 2 3 minutes for thermal ...

Page 28: ...librator Mode Zero Gain Adjustments exclusive of noise on EC models G replaced by L Calibrate L per J Sensor U U T U U T Step Select Input Adjust Reading 1 K 0 000 mV P1 32 0 0 1 F 2 K 54 856 mV P11 2500 0 0 1 F 3 Repeat Steps 1 2 As Required 4 J 0 000 mV P1 32 0 0 1 F 5 T 0 000 mV P1 32 0 0 1 F 6 E 0 000 mV P1 32 0 0 1 F 7 N 0 000 mV P1 32 0 0 1 F 8 B 1 439 mV P1 1000 0 0 5 F 9 R 0 000 mV P1 32 0...

Page 29: ...27 Figure 13 Calibration Setup Calibrator Mode Figure 11 Calibration Setup Copper Mode Figure 12 Calibration Setup Meter Mode ...

Page 30: ...ve humidity less than 80 Preparation For Calibration 1 Turn off unit and remove bottom cover Refer to Disassembly Instructions 2 Secure battery with a piece of adhesive tape NOTE Momentary loss of battery power during the following cal ibration will invalidate previous adjustments both resistance and thermocouple 3 Hook up test equipment and unit per Figure 14 4 Set current source to 1mA STANDBY m...

Page 31: ...29 Figure 14 Resistance Calibration Setup ...

Page 32: ... 2 5 Calibration Adjustments NOTE Do not deviate from the calibration adjustment sequence that follows This will ensure that adjustments to be stored in EEPROM go to the correct locations 1 Perform meter mode adjustments and verifications per Table 3 use Table 5 for RTD Thermistor models 2 Hit OPR key Flashing RTD annunciator turns off 3 Install J1 jumper 4 Set unit to CALIB mode RTD 100 F 5 Switc...

Page 33: ...000 0 00010v 9 10 000Ω 10 0Ω 100µA 0 00100 0 00010v Table 4 Calibration of Calibrator Mode Resistance Functions RTD 100 1000 exclusive of noise Sensor Unit Unit Step Select Input Adjust Verify Reading 1 RTD 100 390 26Ω P1 1562 0 F 2 RTD 100 100 00Ω 32 0 0 3 F 3 RTD 100 18 49Ω 328 0 0 5 F 4 1 000Ω 900 00Ω P1 900 00Ω 5 1 000Ω 1 00Ω 1 00 0 20Ω 6 100 000Ω 90 000Ω P1 90 000Ω 7 100 000Ω 100Ω 100 20Ω 8 T...

Page 34: ...on of Calibrator Mode Resistance Functions RTD Thermistor exclusive of noise 2 CALIBRATION VERIFICATION Calibration is verified with the same instrument hookups as used for calibra tion ie Figures 12 and 13 for thermocouple functions Figure 14 for resis tance functions While one hookup serves to verify all resistance functions RTD thermistor ohms a full check out of thermocouple functions requires...

Page 35: ...el Aluminum alloys Referring to the OMEGA Calibrator s in TC operation Alloy mode means in effect other than Copper mode In order to make accurate measure ments using a thermocouple device one must eliminate erroneous voltage signals In Alloy mode the OMEGA calibrator automatically calculates the cold junction compensation for the selected TC type based on the value s from the ITS 90 table This fe...

Page 36: ... you are in the copper mode 11 While in the copper mode attach the Copper Mode Calibrator Verification Cable to the connector on the top of the CL25 that is labeled T1 Attach the other end of the cable to a precision voltmeter 12 Press the CHANGE function button The 0 0 F display will blink and NUM will appear on the display 13 Press 3 2 0 buttons and then press the ENTER function button NUM will ...

Page 37: ...e voltmeter should read 1 438 mV 25 Press the SENSOR SELECT function button The sensor type will change to type R The B will disappear from the display and a R will appear on the display 26 Press the CHANGE function button The 1000 0 F display will blink and NUM will appear on the display 27 Press 3 2 0 buttons and then press ENTER function button NUM will disappear and 32 0 F will appear not blin...

Page 38: ...ion button The sensor type will change to type K The T and the R will disappear from the display and a K will appear on the display The voltmeter should read 0 000 mV 37 Press the OFF function button The unit will turn off 38 Press the ON function button The unit will power up and return to the cali brator mode CALIB will appear on the display along with the K enuncia tor the OPR enunciator and 32...

Page 39: ...p any where a temperature is transmitted output by the Thermocouple Temperature Simulator you should adjust the Voltage Source to the equivalent voltage as listed by a Type K N I S T ITS 90 Thermocouple Reference Table Example 32 0 F would equal 0 000 mV 8 Press the CHANGE function button and the numerical display will blink and NUM will appear on the display 9 Press 3 2 0 buttons and then press t...

Page 40: ...4 MECHANICAL PARTS DIAGRAM 38 ...

Page 41: ...and the unit under test U U T should have 1 hour to reach thermal equilibrium with ambient tem perature Calibration Adjustments 11 Remove battery from unit under test U U T Refer to Battery Installation Replacement instructions in the manual 12 Remove bottom cover from U U T Refer to Disassembly Instructions 13 Remove calibration jumper J1 from printed circuit board NOTE When installed J1 protects...

Page 42: ...dings 10 Hit OPR key to store K meter zero adjustment in EEPROM Note that FUNC annuciator turns off 11 Select Type J thermocouple KJT key on CL23A SENSOR SELECT key on CL24 12 Turn off U U T 13 Replace K calibration cable with J calibration cable 14 Turn on U U T Note that FUNC annunciator is on again Allow 2 3 min utes for thermal restabilization 15 Apply 32 F Type J Adjust P1 for a reading of 32...

Page 43: ...st P2 for a null meter reading of 0 3µV 35 Set both the U U T and T simulator to output 2400 F Type K Adjust P41 for a null meter reading of 0 3µV NOTE Steps 34 and 35 are interactive Repeat each as neces sary to get the desired null readings 36 Hit OPR key to store K calib zero adjustment 37 Select J thermocouple 38 Turn off U U T 39 Replace K calibration cable with J calibration cable 40 Turn on...

Page 44: ...le 50 Turn off U U T 51 Replace T calibration cable with E calibration cable 52 Turn on U U T Allow 2 3 minutes for thermal stabilization 53 Set both the U U T and thermocouple simulator to 32 0 F Type E Adjust P1 for a null meter reading of 0 3µV 54 Hit OPR Key to store E calib zero adjustment 55 Turn off U U T 56 Remove calibration cover Be careful not to disturb battery connections 57 Re instal...

Page 45: ...43 NOTES ...

Page 46: ...44 NOTES ...

Page 47: ...r otherwise shall not exceed the purchase price of the compo nent upon which liability is based In no event shall OMEGA be liable for consequential incidental or special damages CONDITIONS Equipment sold by OMEGA is not intended to be used nor shall it be used 1 as a Basic Component under 10 CFR 21 NRC used in or with any nuclear installation or activity or 2 in medical applications or used on hum...

Page 48: ...wheel Systems M U Totalizers Batch Controllers pH CONDUCTIVITY M U pH Electrodes Testers Accessories M U Benchtop Laboratory Meters M U Controllers Calibrators Simulators Pumps M U Industrial pH Conductivity Equipment DATA ACQUISITION M U Data Acquisition Engineering Software M U Communications Based Acquisition Systems M U Plug in Cards for Apple IBM Compatibles M U Datalogging Systems M U Record...

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