Emerson Micro Motion LNG Series, Руководство по конфигурации и использованию

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• The stored zero value fails the zero verification procedure.
Prerequisites
Before performing a field zero, execute the Zero Verification procedure to see whether or
not a field zero can improve measurement accuracy.
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.
e. Verify that the process fluid is not flashing or condensing, and that it does not
contain particles that can settle out.
f. Remove or reduce sources of electromechanical noise if appropriate.
g. Observe the drive gain, temperature, and density readings. If they are stable,
check the Live Zero or Field Verification Zero value. If the average value is close to 0,
you should not need to zero the meter.
2. Choose
Device Tools
>
Calibration
>
Zero Verification and Calibration
.
3. Modify
Zero Time
, if desired.
Zero Time controls the amount of time the transmitter takes to determine its zero-
flow reference point. The default Zero Time is 20 seconds. For most applications, the
default Zero Time is appropriate.
4. Click Calibrate Zero .
The
Calibration in Progress
message is displayed. When the calibration is
complete:
• If the zero procedure was successful, a
Calibration Success
message and a
new zero value are displayed.
• If the zero procedure failed, a
Calibration Failed
message is displayed.
Postrequisites
Restore normal flow through the sensor by opening the valves.
Measurement support
62 Micro Motion ® LNG Series Meters