Siemens MAG 1100, Operating Instructions Manual, Page: 160 / 665

85
SITRANS F M 9. Service
9.3
Check list MAG sensor
Disconnect all leads to MAG 1100/3100 or MAG 5100 W
MAG 1100/3100 or MAG 5100 W installed and filled with the medium:
Check coil resistance with a multimeter
R 85-86
Nominal value: See table
Check coil insulation with a megger (500 V)
R 85 - Gnd
Nominal value: Infinite resistance
Check electrode circuit with a moving-coil instru-
ment without amplifier (measurement unstable)
R 82 - Gnd
Nominal value: 5-500 kohm
R 83 - Gnd Nominal value: 5-500 kohm
Sensor apparently OK.
Remove sensor, dry it and check
Sensor may be defective.
Contact Siemens Flow
Instruments
Dirty electrodes or
conductivity too low
NO
NO
> 500 kohm
< 500 kohm
YES
YES
MAG 1100/3100/3100 W or MAG 5100 W removed from system – empty and dry:
Check coil resistance with a multimeter
R 85-86
Nominal value: See table
Check coil insulation with a megger (500 V)
R 85 - Gnd
Nominal value: Infinite resistance
Check electrode insulation with megger (500 V)
R 82 - Gnd
Nominal value: Infinite resistance
R 83 - Gnd Nominal value: Infinite resistance
NO
NO
YES
YES
MAG 1100/3100 or MAG 5100 W OK
YES
Check continuity between electrode and electrode
terminal
R 82 - Electrode
Nominal value: 0 kohm
R 83 - Electrode Nominal value: 0 kohm
YES
Sensor may be defective.
Contact Siemens Flow
Instruments
NO
NO