This is detailed working method of hall effect sensor based water flow switch, a turbine wheel embed with magnet is placed on a closed plastic envelop and a Hall effect sensor placed, When the water flows through the pipeline, it makes the turbine wheel to rotate and hence the magnet flux interferes the hall sensor, the rate of interference is depends on the speed of water flow, so the hall effect sensor produce pulse signal output, this pulse output can be calculated as water volume. Food safe flow meters have been widely used for pharmaceutical, food and other industries. Food safe flow meters mainly have stainless steel turbine flow meter, stainless steel magnetic flow meter, clamp on ultrasonic flow meters and hygiene class hall effect flow sensors. When used for food grade application,the pipe size of hall effect flow meters are usually not over 30 mm. Meanwhile, comparing with other types,hall effect water flow sensors are one of the cheapest solution. Because stainless steel hall effect flow sensor is expensive, it is firstly recommended to consider food class plastic hall effect flow sensor.