Emerson Rosemount5081, Инструкция по эксплуатации, Страница: 73 / 152

Temperature simulation into the 5081-P pH/ORP transmitter Figure 8-4:
• If the measured temperature is correct, the transmitter is working properly.
• If the measured temperature is incorrect, calibrate the transmitter against the
standard resistance equivalent to 25 °C (77 °F). Change the resistance and verify
that the temperature reading changes to the correct value.
- If the transmitter works properly after temperature calibration, the original
calibration was in error. Re-attach the RTD wires and check the temperature
performance of the sensor.
- If the reading is still wrong, the transmitter electronics have failed. Replace
the sensor board stack.
LinE FAIL
LinE FAIL almost always means the transmitter is measuring an incorrect distance between
terminal TB-3 (RTD RTN) and TB-4 (RTD SNS). These terminals are critical connections for
the three-wire RTD measurement.
Figure 8-3 shows a three-wire RTD connection.
Troubleshooting flowchart for LiNE FAIL
1. Check for miswires and open connections at TB-3 and TB-4. Open connections can
be caused by loose connections, poor spade crimps, or broken wires. Be sure the
check junction boxes for proper pass through of all wires.
• If correcting a wiring problem makes the message disappear, the system is in
good condition.
• If the message is still showing, go to Step 2.
2. The RTD sense or the RTD return wire inside the sensor cable may be broken. Keep
the sensor wires attached and jumper TB-3 and TB-4.
Diagnostics and troubleshooting
Instruction Manual 63