Endress+Hauser iTEMP HART TMT142 Manuel De Mise En Service page 76

Trouble-shooting
76
9.3.3 Application errors for TC connection
Error pattern
Error current
(≤ 3.6 mA or ≥ 21 mA)
Error pattern
Measured value is incorrect/
inaccurate
Cause
Sensor connected incorrectly
Sensor defective
Programming
Device defective
Cause
Orientation of the sensor is incorrect
Heat conducted by sensor
Faulty device programming (scaling)
Wrong thermocouple type (TC) configured Change SENSOR TYPE device function
Incorrect comparison measurement point
configured
Offset incorrectly configured
Interference through thermo-wire welded
in thermowell (interference voltage
coupled in)
TMT142
Action/cure
Connect sensor in accordance with
terminal plan (polarity)
Check sensor
Incorrect sensor type configured in the
SENSOR TYPE device function; set correct
thermocouple
Replace device
Action/cure
Install sensor properly
Observe face-to-face length of the sensor
Change scaling
See Section "Description of device
functions"
Check offset
Use sensor that does not have a weld-on
thermo-wire
Endress+Hauser