1. No fluid flowing or the flow rate is under starting flow.

1. Increase the flow rate or replace a flow meter with smaller nominal diameter to meet the requirement of flow range.

2. Make the connection correct.

1. the interference of bad grounding of meter, strong electricity and interference of other grounding.

2. the higher sensitivity of amplifier or it may produce self excitation.

3. Unstable power supply, bad filtering or other electrical disturbance.

1. Make the grounding well

2. Replace the pre-amplifier.

3. Repair or replace the power supply.

1. Unstable flow in pipe

2. the higher or lower sensitivity of amplifier make the output pulses are more counted or less counted.

3. There is debris in the shell of meter.

4. Bad grounding.

5. the flow rate is under the low limit.

6. the downstream seal ring reaches into pipe, and make disturbance.

1. Begin to measure after the flow rate is stable.

2. Replace the pre-amplifier.

3. Remove the debris.

4. Check the grounding, make the grounding well.

1. the flow coefficient of meter is incorrect.

2. the flow rate on site is higher than the maximum flow of meter.

3. the bad quality of the flow meter.

1. Recalibrate the meter and input the new flow coefficient.

2. Reduce the flow rate in pipe or replace the flow meter.

3. Recalibration

Bad contact of the key or dead lock the key

Replace the display board. 

the electrify reset circuit is abnormal, or the oscillating circuit can't afford to boost.

Reinstall the battery (Before reinstall the battery, the meter is needed to discharge more than 5 seconds)