Omega Engineering CL521 Operator's Manual page 22

PtlOO measurement
Switch
Figure 5-6. Pt100 Temperature Probe Measurement with the CL521
The display will indicate the probe temperature, while an arrow at the top of the display
indicates PttOO measurement mode. The displayed temperature units are those most
recently used. To change the temperature units, press the °C/°F key once.
PtlOO temperature measurement works in the range of -200 to 1200°C. If the probe
temperature goes below or above this range, the display will blink the 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 the display indicates
"OPEN," the PttOO sensor is probably broken or incorrectly connected. The TCQ
measurement function can now be used to determine the correct lead assignments.
First determine the probe wiring. Then determine three or four wire lead assignments by
systematically measuring resistances between the various leads.
The TCi2 function is switched on by pressing the TC&mV key followed by the TCQ key.
Return to the PttOO measurement mode by pressing the PtlOO key.
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