Page 1: ...i fcCL521 Temperature Calibrator Thermometer...
Page 2: ...for the unit or units or equipment directly affected by such breach Every precaution for accuracy has been taken in the preparation of this manual however OMEGA ENGINEERING INC neither assumes respon...
Page 3: ...ermocouple Measurements 8 4 3 1 Connections and Reference Junction Mode Selection 8 4 3 2 Measuring Temperature 11 4 3 3 Checking or Changing Reference Junction Temperature 12 4 4 Measuring Thermocoup...
Page 4: ...ng 26 7 3 Millivolt Calibration 27 SECTION 8 RS 232C AND ANALOG OUTPUT OPTION 28 8 1 General Description 28 8 2 Installing the RS 232C Digital Interface Option 28 8 2 1 Data Format and Baud Rate 29 8...
Page 5: ...the features of the CL521 with the addition of RS 232C two way communications and an analog output The RS 232C communications can be used for remote computer control of the unit as well as for transmi...
Page 6: ...type K thermocouple extension cable with male connector calibration certificate TAS U 5 connector and AC power adapter 2 2 REMOVING THE CARRYING CASE In laboratories and maintenance shops the CL521 is...
Page 7: ...s if used during charging 2 4 WIRING CONNECTIONS The CL521 connection terminals are found on top of the unit Connections are easily 3 Pt 0 the way of the display and keypad When using the carrying cas...
Page 8: ...the memory Reference temperature is measured using a Pt100 oc 0 00385 resistance probe Reference temperature is measured using an internal sensor Millivolt measurement 10 to 110 mV Thermocouple resis...
Page 9: ...5 Figure 3 1 Front Panel Functions...
Page 10: ...lectric effect causes a flow of current through the loop corresponding to the temperatures T1 and T2 at the junction points B Figure 4 1 Basic Thermocouple Circuit If the circuit is broken its thermop...
Page 11: ...xample a resistance temperature probe Figure 4 4 Reference Junction Compensation Using a Pt100 Probe The temperature of the reference junctions can also be kept constant by cooling or heating them wit...
Page 12: ...one already Use the polarity marked on the terminal panel Carefully consider whether you shall use copper leads or thermocouple extension cables The extension cable must conform to the thermocouple bo...
Page 13: ...er such conditions accurate reference junction compensation can be ensured by closing the flap on top of the terminal panel during use The instrument is shipped complete with a connecting cable for a...
Page 14: ...h copper wires and the PtIOO probe is connected to the PtIOO terminals I Figure 4 9 Reference Junction Compensation Using a PtIOO Probe C MANUAL REFERENCE JUNCTION COMPENSATION CJ MODE MAN Reference j...
Page 15: ...f needed the required type by pressing the TC TYPE key repeatedly Select the required reference junction compensation mode by pressing the CJ MODE key repeatedly until the arrow at the left edge of th...
Page 16: ...omatically set to zero whenever the manual reference junction compensation mode is selected To check the reference junction temperature or to change it proceed as follows NOTE Make sure the MAN refere...
Page 17: ...521 The resistance measurement range is 0 to 400 ohms Exceeding this range causes the display to blink the maximum allowed resistance If the measurement circuit is broken the display will indicate OPE...
Page 18: ...ure millivolts Reference junction compensation is automatically disconnected the CJ MODE arrow indicates MAN and Register 9 is set to 0 C If the potential being measured goes below 10 mV or above 110...
Page 19: ...eliminating the effect of lead resistance is to use four conductors when measuring the temperature with the probe Two conductors are required to carry the measurement current through the resistance wh...
Page 20: ...lso be measured with three wires The voltage drop in the current circuit is measured and cable effects are compensated for on the assumption that the voltage drop in the feed conductor is identical to...
Page 21: ...a compensation loop is connected to the CL521 similar to the three wire method Figure 5 5 Connecting a 2 Wire Resistance Probe with a Lead Compensation Loop to the CL521 5 3 Pt100 TEMPERATURE MEASURE...
Page 22: ...minimum or maximum value to indicate range underflow or overflow If the measurement circuit is broken the display will indicate OPEN If the temperature reading of the PtlOO sensor is unreasonable or...
Page 23: ...ection c Two Wire Connection with Compensation Loop 5 4 RESISTANCE MEASUREMENT mode is selSed by preSng theS key esistances The resistance measurement Ife 9 9 Ihree or four SSInt SM edge ol Ke a fnSs...
Page 24: ...during a period of 12 seconds If the change is very small however the period is automatically stretched up to two minutes to get better resolution The change in rate display is obtained by pressing t...
Page 25: ...MOCOUPLE SIMULATION AND MILLIVOLT CALIBRATION 7 1 PRINCIPLE OF THERMOCOUPLE SIMULATION Thermocouple simulation refers to the process of replacing a thermocouple with a device which mimics the function...
Page 26: ...unt for reference junction temperature Remember to use the correct type and polarity of extension wires B REFERENCE JUNCTION COMPENSATION USING A PttOO PROBE CJ MODE PROBE The CL521 is connected to th...
Page 27: ...mpensation or compensation has been disconnected The CL521 is connected directly to the device with copper conductors Compensation is not necessary since no thermoelectric potentials are present in th...
Page 28: ...measurement and displays a value of 0 If the displayed value is in millivolts the arrow at the right edge of the display points to mV change the units to temperature by pressing the TC mV key once Sel...
Page 29: ...meric pad To enter for example 25 C enter 2 5 ENT Recalling values from memory Registers 0 to 6 Frequently used calibration values can be stored into memory Registers 0 to 6 The register values are ke...
Page 30: ...d to about 0 6 mA E 60 mV Thus the stabilization time of the simulation value increases when devices that cause circuit loading such as wirewound meter movement devices are being checked If the device...
Page 31: ...ser enters the required temperature values and the CL521 provides the corresponding millivoltage to the TC and mV terminals Millivolt values can also be entered directly as millivolts for output at th...
Page 32: ...elected Output is isolated from the measurement circuits Accuracy 0 2 rdg 1 degree 0 1 mV or 0 1 ohm in normal measurement 0 2 rdg 0 1 degree 0 01 mV or 0 01 ohm in deviation measurement 8 2 INSTALLIN...
Page 33: ...s not care about the state of the bit b7 1 0 start bit b a 2 6 7 stop bit ___ Figure 8 2 Serial Data Format The data format of the computer or the printer must be set to conform to the data format of...
Page 34: ...eded in all devices Some microcomputers are wired as DTE devices The cable of Figure 8 4 with one additional wire from the computer connector Pin 2 to the Cl_521 connector Pin 3 can normally be used i...
Page 35: ...sition Key in 6 0 STO 7 The output message string consists of the following parts Char 1 Main function M Measurement C Calibration Chars 3 4 Sensor type E Chromega Const R Pt13 Rh Pt S Pt10 Rh Pt B Pt...
Page 36: ...terface After a command from the computer is received all further keypad operations are neglected until the FO command from the computer is received The usable computer commands are listed below A Fun...
Page 37: ...tput After the CL521 is switched ON all output messages are followed by the codes CR ODH and NUL OOH If the printer cannot feed the paper with this end character combination the end characters can be...
Page 38: ...The baud rate is set to 600 bits s 3 the data format is eight data bits 8 no parity bit N and one stop bit 1 No hand shaking is used in the data transfer F PI causes output of one message and disables...
Page 39: ...needed between the commands to give the CL521 time to execute the earlier commands No other commands can be series connected to the same command string after a V command The special function commands...
Page 40: ...there is extra characters on the line it would disturb the program execution later 20 PRINT 1 PI 25 WHILE LOC 1 0 28 L INPUT 1 1 30 WEND The thermocouple measurement with TC type K is selected and on...
Page 41: ...8 if the temperature is changed 1 2 degrees or more the time and the temperature is printed 180 iP ABS T XT 5 AND START 0 THEN GOTO 150 190 LPRiNT TiME USiNG C T 200 XT T START 0 Next measurement 210...
Page 42: ...voltage 595 to 3500 mV 595 to 3500 mV 595 to 3500 mV 595 to 3500 mV SECTION 9 SERVICE AND CALIBRATION CL521 does not need any regular service except for calibration checks In case the unit is not fun...
Page 43: ...ermocouple measurement type K thermocouple and internal reference junction compensation Connect the tj e K thermocouple probe and put it into a 0 C ice bath or OMEGA TRCIII The display should show 0 C...
Page 44: ...rdg 6 mV thermocouple and mV 0 02 rdg 0 04 ohms RTD and Resistance COLD JUNCTION COMPENSATION ERROR 0 2 C at 23 C 0 01 C C TEMPERATURE COEFFICIENT 0 002 C OPERATING AMBIENT RANGE 14 tO 122 10 tO 50 C...
Page 45: ...Cr CuNi ASTM E230 250 to 220 0 1 0 2 Chromega Const 220 to 1000 0 1 0 1 R lEC 584 1 50 to 250 0 1 0 5 R13 Rh R ASTM E230 250 to 1768 0 1 0 2 S lEC 584 1 50 to 600 0 1 Pt10 Rh R ASTM E230 DIN 43710 600...
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