GB
11258421.0901/2012GB/D
42 WIKAoperatinginstructionstemperaturetransmitterT32.xS
12. Faults
12. Faults
Fault-tree
l=0mA
Currentloop
disconnected
Wrongpolarityofthe
supplyvoltage
Transmitternot
connected
Wrongsensortype
Wrong2-,3-or
4-wireconnection
Wrong
temperaturerange
Wrong
compensation
Sensor=
TC
Sensor=
RTD
l>20mA
l<4mA
4mA<l<20mA
butwrongvalues
Currentvalueisokay,but
temperaturedriftwhile
transmitterisheatingupor
coolingdown
Processtemperature
outofrange
Wrongsensor
connection
Sensorburnoutor
shortcircuit
Wrongtransmitter
conguration
Capacitiveor
inductivecoupling
overthesensor
Capacitiveor
inductivecoupling
overtheloop
Wrongpolarityof
thermocouple
Loopresistancetoohigh
Electromagnetic
interferences
Linearizationerrorfor
sensor/transmitter
Currentvaluefallswhile
measuringtemperaturerises
(andviceversa)
Currentvalueisokayatlow
values,buttoolowathigher
temperatures
Currentvalueisunstableand
changeswithinseconds
Temperaturevaluesonly
correctatthemeasuringlimits