3-wire RTD temperature transmitter shown reading in DCS -272 Deg C?
The cable was removed from the sensor, the resistance was checked (normal ohms), and the DCS reading in not changed.
Also, continuity test through all cables is tested, still the same value?
While connecting the cable to the sensor, the resistance changed to 90.6 ohms???
If the RTD was working fine, then check the transmitter output.
Check the transmitter output 4-20 mA output with respect to the RTD resistance.
The transmitter output current must vary and the DCS must receive this current.
If the DCS receives the correct current from the transmitter, the DCS must show correct temperature reading.
If not, then check the barriers or AI card channel status in the PLC or DCS system.
