Emerson Process Management 1500 manual 11.11Checking process variables

Troubleshooting

11.11Checking process variables

Micro Motion suggests that you make a record of the process variables listed below, under normal operating conditions. This will help you recognize when the process variables are unusually high or low. The meter fingerprinting feature can also provide useful data (see Section 11.12).

•Flow rate

•Density

•Temperature

•Tube frequency

•Pickoff voltage

•Drive gain

For troubleshooting, check the process variables under both normal flow and tubes-full no-flow conditions. Except for flow rate, you should see little or no change between flow and no-flow conditions. If you see a significant difference, record the values and contact Micro Motion customer service for assistance. See Section 1.8.

Unusual values for process variables may indicate a variety of different problems. Table 11-5 lists several possible problems and remedies.

Table 11-5Process variables problems and possible remedies

Symptom Cause Possible remedy

Steady non-zero flow rate under no-flow conditions

Misaligned piping (especially in new	Correct the piping.
installations)

Open or leaking valve	Check or correct the valve mechanism.
Bad sensor zero	Rezero the flowmeter. See Section 3.5.
Bad flow calibration factor	Verify characterization. See
	Section 4.2.

98 Micro Motion® Model 1500 Transmitters with the Filling and Dosing Application