27
2.10
Troubleshooting Guide
Symptom
Possible
Cause
Solution
Meter
Readings are
High
Output Signal
Interference
-
confirm shielded cable has been used
- ground cable shield at instrument end only
- isolate cable shield at flowmeter end
- re-route cabling from high electrical energy sources, or
power carrying cables such as valves and pumps/motors.
Entrained air
or gas
- Remove source of air or gas entrapment
- Install an upstream air-eliminator
Pulsating Flow
from
reciprocating
style pump
- Increase back pressure on pump
- Install a fast response one-way (check) valve, or a surge
arrestor between pump and meter
- Change pump style to a smooth delivery pump
Meter
Readings are
Low
Damaged or
worn rotors
Inspect, repair, clean, or replace rotors
Damage or
worn
measuring
chamber
Inspect measuring chamber for damage and consult
manufacturer for advice.
Output signal
interference
- Confirm correct wiring with shielded cable
- Check all electrical connections for firmness and continuity
No Output
from
Flowmeter
Rotors
jammed
- If meter has been recently field serviced, check that rotors
are not installed upside-down or incorrectly meshed
- Check for obstruction due to foreign particles
- Clean, repair, or replace rotors
Meter
incorrectly
reassembled
Consult manufacturer for advice.
No signal from
Pulse Output
Board
- Check terminal connections
- Ensure DC voltage is available at the terminals of the PCB,
and pull-up resistor is fitted if Hall Effect output is used.
- Ensure receiving instrument is configured correctly.
- Check voltage/current are within maximum ratings
Not Reading
on Receiving
Instrument
Faulty
receiving
instrument
- Check hardware and software settings; DIP switches,
terminal connections, and programming settings
- Repair or replace receiving instrument
