WIKA TR10-0 Betriebsanleitung Seite 17

8. Faults
Faults
No signal/line break
Erroneous measured
values
Erroneous measured
values (too low)
Erroneous measured
values and response
times too long
Erroneous
measured values (of
thermocouples)
Indication of the
measured value jumps
Corrosion
Signal interference
WIKA operating instructions models TR10-0, TC10-0 (FM, CSA)
Causes
Mechanical load too high or
overtemperature
Sensor drift caused by
overtemperature
Sensor drift caused by chemical
attack
Entry of moisture into cable or
measuring insert
Wrong mounting geometry, for
example mounting depth too deep
or heat dissipation too high
Deposits on the sensor or
thermowell
Parasitic voltages (thermal
voltages, galvanic voltage) or
wrong equalisation line
Cable break in connection cable
or loose contact caused by
mechanical overload
Composition of the medium not
as expected or modified or wrong
thermowell material selected
Stray currents caused by electric
fields or earth circuits
Earth circuits
Measures
Replacement of the sensor or the
measuring insert with a suitable version
Replacement of the sensor or the
measuring insert with a suitable version
Use of a suitable thermowell
Replacement of the sensor or the
measuring insert with a suitable version
The temperature-sensitive area of the
sensor must be inside the medium, and
surfaces must be ungrounded
Remove deposits
Check polarity
Use of a suitable equalisation line
Replacement of the sensor or measuring
insert with a suitable design, for example
fitted with strain relief or a thicker
conductor cross-section
Analyse medium and then select a more
suitable material or replace thermowell
regularly
Use of screened connection cables,
increase in the distance to motors and
power lines
Elimination of potentials, use of
galvanically isolated transmitter supply
isolators or transmitters
EN
17