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47DT OPERATING MANUAL EM-9508-B Rev.7
18. SETTING COLD JUNCTION COMPENSATION (CJC) SENSOR
Temperature difference between the measuring point (temperature measuring junction) and the terminals of the 47DT
(reference junction) generates thermal electromotive force (emf). When the temperature at the reference junction var-
ies, the emf also varies even though the temperature at the measuring junction is same. To solve the problem, electrical
compensation is performed by detecting the temperature at the reference junction with a temperature sensor and adding
the emf for the temperature, which is called reference or cold junction compensation. The temperature sensor to detect the
temperature at the reference junction is called reference or cold junction sensor.
To use the CJC sensor of the 47DT, enable the CJC sensor ‘ON’. When an external reference junction compensator is
used, disable it ‘OFF’. The default is ‘ON’.
18.1 OPERATING PROCEDURE
NOTE
The following figures are display examples. The displays
depend on the specifications and settings.
1
Hold down Alarm/
↓
and Init/
↑
buttons at once for 3 seconds or
more to move on to Advanced Setting Mode.
• The averaging type is indicated.
• The SD indicates ‘AVE-TP’.
NOTE
With the I/O option code ‘6’ or ‘A’, the event trigger mode is indicated (‘EVENT’ on the SD).
2
Press Alarm/
↓
or Init/
↑
button to go to the CJC sensor setting.
• The CJC sensor is indicated.
• The SD indicates ‘CJM’.
1,2,
4,5
1,2,
4,5
3
3
