WIKA TR10-L Manual De Instrucciones página 25

6. Faults
Faults
No signal/Cable break
Erroneous measured
values
Erroneous measured
values (too low)
Erroneous measured
values and response times
too long
Erroneous
measured values (of
thermocouples)
Display of measured value
jumps
Corrosion
Signal interference
WIKA operating instructions, models TR10-L, TC10-L, TR10-0, TC10-0 (Ex d)
Causes
Mechanical load too high or
overtemperature
Sensor drift caused by
overtemperature
Sensor drift caused by chemi-
cal attack
Entry of moisture into cable or
measuring insert
Wrong mounting geometry,
e.g. insertion depth too small
or heat dissipation too high
Deposits on the sensor or
thermowell/protection tube
Parasitic voltages (thermo-
electric voltages, galvanic
voltage) or wrong compensat-
ing cable
Cable break in connection
cable or loose contact caused
by mechanical overload
Composition of the medium
not as expected or modified or
wrong thermowell/protection
tube material selected
Stray currents caused by
electric fields or ground loops
Ground loops
Measures
Replacement of the probe or
the measuring insert with a
suitable version
Replacement of the probe or
the measuring insert with a
suitable version
Use of a suitable thermowell/
protection tube
Replacement of the probe or
the measuring insert with a
suitable version
The temperature-sensitive
area of the sensor must
be inside the medium, and
surface measurements must
be ungrounded
Remove deposits
Check polarity
Use of a suitable compensat-
ing cable
Replacement of the sensor
or measuring insert with a
suitable design, for example
fitted with a bend protection
spring or a thicker conductor
cross-section
Analyse medium and then
select a more suitable material
or replace thermowell/protec-
tion tube regularly
Use of screened connec-
tion cables, increase in the
distance to motors and power
lines
Elimination of potentials,
use of galvanically isolated
repeater power supplies or
transmitters
EN
25