Selecting a liquid-level float switch

摘要

Liquid-level switches used in aircraft, nuclear-power plants, medical equipment, and other critical applications must be precise and reliable. For that to happen, design engineers must know the application and options to choose just the right switch. One of the most common level-sensing switches is the float switch. It consists of a float holding a magnet and a dry reed switch encapsulated within a stem. As the float follows-the level of liquid in the vessel, the magnet also moves up and down. The magnet activates the reed switch when they're both at the same level, providing an "on" or "off" signal. The signal can be conditioned to activate alarms and controllers or complete a circuit that turns on pumps to fill a tank. Float switches come in many styles, sizes, and materials.