Emerson Micro Motion 4200, Руководство по конфигурации и использованию

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a) Set
Specify Time Until Next Run
to
0
days
,
0
hours
, and
0
minutes
.
b) Set Specify Time Between Recurring Runs to
0
days ,
0
hours , and
0
minutes .
12.2 Zero the meter
Display
Menu
>
Service Tools
>
Verification & Calibration
>
Meter Zero
>
Zero Calibration
ProLink III Device Tools > Calibration > Smart Zero Verification and Calibration > Calibrate Zero
Field Communicator Service Tools > Maintenance > Calibration > Zero Calibration > Perform Auto Zero
Zeroing the meter establishes a baseline for process measurement by analyzing the sensor's output when
there is no flow through the sensor tubes.
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
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) 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. 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.
Measurement support Configuration and Use Manual
April 2019 MMI-20048166
132 Micro Motion 4200 Transmitters