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.
Procedure
1.
Allow the flowmeter to warm up for at least 20 minutes after applying power.
2.
Run the process fluid through the sensor until the sensor temperature reaches the
normal process operating temperature.
3.
Stop flow through the sensor by shutting the downstream valve, and then the
upstream valve if available.
4.
Verify that the sensor is blocked in, that flow has stopped, and that the sensor is
completely full of process fluid.
5.
From ProLink III, choose Device Tools > Calibration > Zero Verification and
Calibration > Verify Zero and wait until the procedure completes.
6.
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.
7.
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. Remove or reduce sources of electromechanical noise if appropriate.
d. Repeat the zero verification procedure.
e. If it fails again, zero the meter.
Postrequisites
Restore normal flow through the sensor by opening the valves.
Related information
2.6.1
Terminology used with zero verification and zero
calibration
Term
Definition
Zero
In general, the offset required to synchronize the left pickoff and the right
pickoff under conditions of zero flow. Unit = microseconds.
Factory Zero
The zero value obtained at the factory, under laboratory conditions.
Quick start
8
Micro Motion Model 2500 Transmitters with Configurable Input/Outputs
Summary of Contents for Micro Motion 2500
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