Instruction manual

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MODEL Xmt-P SECTION 10.0
TROUBLESHOOTING
10.3 TROUBLESHOOTING WHEN NO FAULT MESSAGE IS SHOWING - TEMPERATURE
10.3.1 Temperature measured by standard was more than 1°C different from controller.
A. Is the standard thermometer, RTD, or thermistor accurate? General purpose liquid-in-glass thermometers, par-
ticularly ones that have been mistreated, can have surprisingly large errors.
B. Is the temperature element in the sensor completely submerged in the liquid?
C. Is the standard temperature sensor submerged to the correct level?
10.4 TROUBLESHOOTING WHEN NO FAULT MESSAGE IS SHOWING - HART
A. If the Model 375 or 275 Communicator software does not recognize the Model Xmt-P transmitter, order an
upgrade from Rosemount Measurement at [phone].
B. Be sure the HART load and voltage requirements are met.
1. HART communications requires a minimum 250 ohm load in the current loop.
2. Install a 250-500 ohm resistor in series with the current loop. Check the actual resistor value with an
ohmmeter.
3. For HART communications, the power supply voltage must be at least 18 Vdc. See Section 2.4.
C. Be sure the HART Communicator is properly connected.
1. The Communicator leads must be connected across the load.
2. The Communicator can be connected across the power terminals (TB2).
D. Verify that the Model 375 or 275 is working correctly by testing it on another HART Smart device.
1. If the Communicator is working, the transmitter electronics may have failed. Call Rosemount Analytical
for assistance.
2. If the Communicator seems to be malfunctioning, call Rosemount Measurement at [phone] for
assistance.
10.5 TROUBLESHOOTING WHEN NO FAULT MESSAGE IS SHOWING - pH
Problem See Section
Warning or error message during two-point calibration 10.5.1
Warning or error message during standardization 10.5.2
Controller will not accept manual slope 10.5.3
Sensor does not respond to known pH changes 10.5.4
Calibration was successful, but process pH is slightly different from expected value 10.5.5
Calibration was successful, but process pH is grossly wrong and/or noisy 10.5.6
Process reading is noisy 10.5.7