Chapter 6 Maintenance and overhaul
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6.2. Possible failures of the flow meter and solutions
Table 5 Common faults and solutions of flow meters
Failure phenomenon
the reason
solutions
No display on display
instrument
(Or no current signal)
1. The power is not connected or
the fuse is blown
2. The display instrument is faulty
3. Battery failure
1. Turn on the power or
replace the fuse
2. Overhaul the display
instrument
3. Replace the battery
The display instrument
has display on the
calibration signal but no
display on the flow signal
(or the output current is
incorrect)
1. The sensor and display
instrument wiring is wrong
2. Amplifier failure
3. The converter (coil) is open or
shorted
4. The impeller is stuck
5. No fluid flow or blockage in the
pipeline
1. Check the correctness
and quality of the wiring
2. Repair or replace the
amplifier
3. Repair or replace the
coil
4. Clean sensor and
pipeline...
5. Open the valve or pump
and clean the pipeline
Incorrect measurement
or unstable display (or
incorrect output current)
1. The actual flow exceeds the
measuring range of the sensor
2. The meter coefficient K is set
incorrectly
3. The sensor is entangled by fiber
impurities
4. There are bubbles in the liquid
5. There is a strong
electromagnetic field near the
sensor
6. The sensor bearing and shaft
are severely worn
7. The sensor cable shielding layer
or other grounding wires are
disconnected from the line
grounding wire or have poor
contact
8. Display instrument failure
1. Adjust the measured
flow rate to match the
measuring range of the
sensor
2. Make the meter
coefficient K set correctly
3. Clean the sensor parts
4. Take degassing
measures to eliminate
bubbles
5. Stay away from
interference sources or
take shielding measures
6. Replace the guide or
impeller shaft
7. Check the wiring
8. Overhaul display
instrument
