Troubleshooting/Faqs; Sensor Check - Siemens SITRANS F M MAG 3100 sensor Operating Instructions Manual

Troubleshooting/FAQs

7.1

Sensor check

Requirement
To check the SITRANS F M sensors the following test instruments will be required:
● Digital Meter/Multimeter
● Megger
● (Moving Coil Meter)
Sensor check
Remove the transmitter from the sensor or remote position before making the following
checks.
Coil resistance check
● Measure the coil resistance between connection numbers 85 and 86 using a digital
A low reading may indicate moisture within the coil housing or shorted coil tums.
A high reading would indicate an open circuit coil.
Note
In case of deviation from nominal coil values, the sensor is damaged and must be replaced
Coil insulation check
Potential hazard!
Only carry out a coil insulation check in non-hazardous area!
● Megger between connection number 85 and the sensor body.
● A low megger reading would indicate the coil insulation is braking down. This is normally
● Sensors with an insulation resistance down to 1 MΩ may still work satisfactorily but this is
SITRANS F M MAG 3100 sensor
Operating Instructions, 09/2012, A5E03005599-02
meter.
Resistance should be within range stated in Coil resistance table.
WARNING
The resistance should be above 20 MΩ.
due to fluid ingress into the coil housing.
not guaranteed.
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