Emerson Micro Motion LNG Series, Configuration And Use Manual

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The zero verification procedure analyzes the Live Zero value under conditions of zero flow,
and compares it to the Zero Stability range for the sensor. If the average Live Zero value is
within a reasonable range, the zero value stored in the transmitter is valid. Performing a
field calibration will not improve measurement accuracy.
2.6.1 Verify the zero using ProLink III
Verifying the zero helps you determine if the stored zero value is appropriate to your
installation, or if a field zero can improve measurement accuracy.
Important
In most cases, the factory zero is more accurate than the field zero. Do not zero the meter unless one
of the following is true:
• The zero is required by site procedures.
• The stored zero value fails the zero verification procedure.
Prerequisites
ProLink III v3.5, or a later release
Important
Do not verify the zero or zero the meter if a high-severity alert is active. Correct the problem, then
verify the zero or zero the meter. You may verify the zero or zero the meter if a low-severity alert is
active.
Procedure
1. Prepare the meter:
a. Allow the meter to warm up for at least 20 minutes after applying power.
b. Run the process fluid through the sensor until the sensor temperature reaches
the normal process operating temperature.
c. Stop flow through the sensor by shutting the downstream valve, and then the
upstream valve if available.
d. Verify that the sensor is blocked in, that flow has stopped, and that the sensor is
completely full of process fluid.
2. Choose
Device Tools
>
Device Calibration
>
Zero Verification and Calibration
>
Verify Zero
and
wait until the procedure completes.
3. If the zero verification procedure fails:
a. Confirm that the sensor is completely blocked in, that flow has stopped, and that
the sensor is completely full of process fluid.
b. Verify that the process fluid is not flashing or condensing, and that it does not
contain particles that can settle out.
c. Repeat the zero verification procedure.
d. If it fails again, zero the meter.
Quick start
10 Micro Motion ® LNG Series Meters