Anderson IZMSG, Инструкция по эксплуатации

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A-8
IZMSG Compact Electromagnetic Flowmeter
AIC 2071
Zero Test Troubleshooting
(Converter with LCD Display or using MSD Service Display)
Zero Test values can be useful for troubleshooting a flowmeter problem or
revealing a hidden condition that may have an adverse effect on flowmeter
performance. See Section 4,
Start-Up and Commissioning
, for the procedure
to conduct a Zero Test.
Comparing Zero Adjust and Zero Test Values
The zero value stored in the converter memory may be displayed by entering
Menu 70. See Section 5,
Using the LCD Display
, for use of the keypad menu
functions.
The stored zero value is the result of the last Zero Adjust conducted on the
flowmeter which probably occurred when the flowmeter was installed.
Assuming that the original installation conditions have not changed, there
should be no substantial difference between the current Zero Test value and
the original stored Zero Adjust value.
If there is a gross difference of 75 to 100 units or more between the current
Zero Test measurement and the stored Zero Adjust value, then there is a
strong possibility that a problem exists. Check the connection cable wiring
for loose connections and for corrosion in the meter body terminal box.
Conduct a Dry Meter Body Resistance Check to determine if there has been
an insulation breakdown due to internal contamination of the meter body.
Repeating Zero Test Measurement
When conducting several Zero Tests in succession under identical
conditions, the repeated zero measurements should be within ±2 units. The
inability to achieve uniformity of results from repeated Zero Test
measurements indicates a problem in connection cable wiring, corrosion of
the connection cable terminations, or meter body insulation breakdown due
to internal contamination. Refer to the Dry Meter Body Resistance Check.