What causes a water meter to run automatically or exhibit pointer jitter?

1. Water hammer and pipe impact:
After the water supply system valves are closed, the inertia of the water flow causes a momentary pressure increase. Air is compressed and rebounds, forming a water hammer, which causes abnormal force on the impeller inside the water meter, resulting in automatic running or pointer jitter.

2. Air trapped in the pipes:
After long-term disuse or renovation, residual air in the pipes, when compressed, causes the water meter to rotate, resulting in pointer jitter.

3. Water pressure fluctuations:
Water usage by nearby users, the start and stop of the water pump, or pressure regulation in the pipe network can all cause local water pressure fluctuations, resulting in pointer jitter, which is a normal pressure response.

4. Mechanical wear or improper installation:
Wear and tear on internal components of an aging water meter, poor sealing, or incorrect installation angles can amplify the effects of the above factors, making the automatic running phenomenon more pronounced.