Pressure switches are electrical components that sense changes in liquid and/or gas pressure and react with a preprogrammed response. Specifically, they open or close when activated at certain pressure points, or actuation points, or in other words, when pressure reaches a predetermined level, whether it be rising or falling, on their input.
Pressure switches can sense pressure with the assistance of a variety of mechanisms, such as piezoresistive pressure sensors, elastomeric diaphragms, and pressure transducers. Piezoresistive pressure sensors are commonly employed by electric pressure switches.