Analysis of Chattering Error on Reed Switch for AMR System of Water Supply

The chattering error of reed switch sensors for Automatic Meter Reading system of water flow meter was analyzed according to various types of external vibrations and shocks. The vibration level amplitude was measured with an accelerometer. To apply for water flow measurement devices, the reed switch sensors should keep high reliability. But the measured digital meter data is occurred difference or errors by chattering noise. The reed switch contains chattering error by itself at the force equivalent position. The vibrations such as passing vehicle near to the reed switch installed location causes chattering. In order to reduce chattering error, most system uses just software methods, for example using digital filter algorithm and also statistical calibration methods. However software approaches were implemented for reducing chattering error there has still generated chattering error due to external mechanical vibrations and magnetic field. The chattering errors can be reduced by changing leaf spring structure using mechanical hysteresis characteristics.