Hall Sensor

Detects the presence of a magnetic field with no physical contact, so there is nothing to wear out. Used for door and window sensors, rotation counting on a wheel or shaft, position limits and speed measurement. Because it is non-contact and sealed from dust and water, it lasts far longer than a mechanical switch in dirty or wet environments. Some versions respond only to one magnetic pole, so if it does not trigger, try flipping the magnet. Non-contact sensing with no mechanical wear; Works through plastic, wood and non-magnetic materials; Unaffected by dust, water and dirt; Fast response suits RPM counting