Emerson 9739 Manuel D’Utilisation
Flow measurement problems and recommended actions
(continued)
Table 10-3:
Problem
Possible causes
Recommended actions
Inaccurate flow rate
or batch total
or batch total
•
Wiring problem
•
Inappropriate measurement unit
•
Incorrect flow calibration factor
•
Incorrect meter factor
•
Incorrect density calibration factors
•
Incorrect flowmeter grounding
•
Slug flow
•
Problem with receiving device
•
Check the wiring between the sensor and
transmitter. See
transmitter. See
.
•
Verify that the measurement units are con-
figured correctly for your application.
figured correctly for your application.
•
Verify that all of the characterization parame-
ters match the data on the sensor tag.
ters match the data on the sensor tag.
•
Zero the meter.
•
.
•
Check for slug flow. See
•
Verify that the receiving device, and the wir-
ing between the transmitter and the receiv-
ing device.
ing between the transmitter and the receiv-
ing device.
•
Check sensor coil resistance and for shorts to
case. See
case. See
•
Replace the core processor or transmitter.
10.4
Density measurement problems
Density measurement problems and recommended actions
Table 10-4:
Problem
Possible causes
Recommended actions
Inaccurate density
reading
reading
•
Problem with process fluid
•
Incorrect density calibration factors
•
Wiring problem
•
Incorrect flowmeter grounding
•
Slug flow
•
Plugged or coated flow tube
•
Incorrect sensor orientation
•
RTD failure
•
Physical characteristics of sensor have
changed
changed
•
Check the wiring between the sensor and
transmitter. See
transmitter. See
.
•
.
•
Check your process conditions against the
values reported by the flowmeter.
values reported by the flowmeter.
•
Verify that all of the characterization parame-
ters match the data on the sensor tag.
ters match the data on the sensor tag.
•
Check for slug flow. See
•
If two sensors with similar frequency are too
near each other, separate them.
near each other, separate them.
•
Purge the flow tubes.
Unusually high densi-
ty reading
ty reading
•
Plugged or coated flow tube
•
Incorrect K2 value
•
Incorrect temperature measurement
•
RTD problem
•
In high frequency meters, this can be an
indication of erosion or corrosion
indication of erosion or corrosion
•
In low frequency meters this can indi-
cate tube fouling
cate tube fouling
•
Verify that all of the characterization parame-
ters match the data on the sensor tag.
ters match the data on the sensor tag.
•
Purge the flow tubes.
•
Check for coating in the flow tubes.
Troubleshooting
168
Micro Motion
®
9739 MVD Transmitters