Metex 3200U Ultrasonic Flow & Level Monitor - Manual (Page 25)

FIELD TROUBLESHOOTING
SYMPTOMS CHECK
Display - full scale A
- zero B
- erratic - random C
- drifting up D
- drifting down E
ECHO LOSS prompt - flashing F
Calibration Non-Linear H
SYMPTOMS FAULTS SOLUTIONS
Unit “See’s” Wrong Target Due To:
A,C,D,F - sensor not aimed correctly
A,F,D - condensation/dust/dirt buildup on
sensor
- Clean carefully (do not scratch sensor face)
A,D - sensor mounting stand pipe - Lower Sensor below stand pipe intrusion
- too long / - too narrow
- dirty / - gasket intruding
C,E - very turbulent flow in open channel - Increase RejTime (CALIBRATION menu)
- install stilling well on flume or weir
C,E - very turbulent level in tank - Increase RejTime (CALIBRATION menu)
- change tank fill method
Unit Picks-Up Interference Due To:
A,C - noise from high pressure fill - Install submerged fill pipe
A,D - sensor coupling over tightened - Hand tighten only (like a light bulb)
A,D - sensor coupling not used - Use coupling supplied
C - other ultrasonic unit in close proximity - Synchronize
Electrical interference:
C - sensor cable connections reversed
C,G - through sensor cable - Use properly grounded metal conduit
C - sensor cable extended and junction not
insulated
- Use metal Junction Box
C,G - through enclosure - Use metal enclosure
C,G - through 4-20mA output cable - Use shielded twisted pair (shielded to AC
ground)
- Use grounded metal conduit
C,G - wiring or installation close to variable
speed drive or inverter
- Follow V.S.D. manufacturer’s instructions
for Drive grounding, wiring and shielding
AquaMetrix
Ultrason
Page 25