Emerson Process Management 2400S manual Uncertainty limit and test results

Measurement Performance

10.3.1Uncertainty limit and test results

The result of the meter verification test will be a percent uncertainty of normalized tube stiffness. The default limit for this uncertainty is ±4.0%. This limit is stored in the transmitter, and can be changed with ProLink II or a DeviceNet tool when optional test parameters are entered. For most installations, it is advisable to leave the uncertainty limit at the default value.

When the test is completed, the result will be reported as Pass, Fail/Caution (depending on the tool you are using), or Abort:

•Pass – The test result is within the specified uncertainty limit. If transmitter zero and configuration match factory values, the sensor will meet factory specifications for flow and density measurement. It is expected that the meter will pass meter verification every time the test is run.

•Fail/Caution – The test result is not within the specified uncertainty limit. Micro Motion recommends that you immediately re-run the meter verification test. If the meter passes the second test, the first Fail/Caution result can be ignored. If the meter fails the second test, the flow tubes may be damaged. Use the knowledge of your process to consider the type of damage and determine the appropriate action. These actions might include removing the meter from service and physically inspecting the tubes. At minimum, you should perform a flow validation (see Section 10.4) and a density calibration (see Section 10.6).

•Abort – A problem occurred with the meter verification test (e.g., process instability). Check your process and retry the test.

ProLink II provides more detailed test data. See Section 10.3.2.

96 Micro Motion® Model 2400S Transmitters for DeviceNet™