FIELD TROUBLESHOOTING
Possible Causes:
Corrective Action:
METER READING LOWER THAN EXPECTED
Calibration Error
·
Review
UNITS/MODE
menu and
Pipe ID
Lower flow rate than expected
·
Investigate pump/valves. Compare velocity
with alternate instrument
Signal not penetrating far enough into the flow
stream
·
Increase sensitivity
·
Relocate sensor closer to elbows or flow
disturbances
Laminar flow condition or high solids/bubbles
content in liquid
·
Remount Sensor at 12 o'clock position on
horizontal pipe
Improper mounting of sensor
·
Reinstall Sensor with careful application of
Coupling Compound
Pipe is not full
·
Remount Sensor on vertical pipe
METER READING WHEN THERE IS NO FLOW
Vibration on pipe
·
Install in another location
Local electrical noise
·
Ensure all Flowmeter wiring is in METAL
conduit and sensor shield is properly grounded.
·
Ensure correct power input Ground connection
(<1 ohm resistance).
·
Ensure 4-20mA Shield connected to
Instrument Ground stud.
·
Reduce DFM Sensitivity setting.
Cross talk between two or more DFM-IV
flowmeters on same pipe
·
Turn OFF one flowmeter or follow
synchronization procedure for two or more
DFM-IV Flowmeters.
Variable Speed Drive interference
·
Follow Drive manufacturers wiring and
Grounding instructions
·
Relocate Flowmeter electronics, Sensor and
wiring away from VSD
Page 19
DFM-IV Doppler Flow Meter
Manual Series A.6
