SITRANS F M TRANSMAG 2
Operating Instructions, 11/2009, A5E00102775-07
65
Troubleshooting
9
9.1
Quick sensor check-up
Resistance check
Between the sensor terminals 5 and 6, the resistance should be between 8 and 20Ω, when
the transmitter is disconnected. If the measured value is outside the recommended area, the
sensor is defective.
Isolation check
Between sensor terminal 5 and 7 as well as 6 and 7, the resistance must be ≥10 MΩ. If this
is not the case, humidity is present in the sensor. The check can also be carried out with the
sensor cable connected. If the measured values are too low, the sensor is defective.
CAUTION
Make sure the transmitter is disconnected during resistance and isolation check!
Check of electrode circuit
For sensors with SmartPLUG, the voltage must be:
● - 5.3 V DC ± 10% between terminal 22 and 29
● + 5.3 V DC ± 10% between terminal 22 and 30
This should be measured directly at the transmitter and then at the sensor.
If the measured values are too low, transmitter is defective.
If the measured values are zero or with a wrong polarity, check cable leads.
See also
If the sensor or transmitter is defective, contact your local Siemens representative:
Local contact person (
http://www.automation.siemens.com/partner
)