pressure switch

pressure switch

[′presh·ər ‚swich] (electricity) A switch that is actuated by a change in pressure of a gas or liquid.

pressure switch

A switch used to turn an electrical device on or off when a specified fluid pressure is reached. For example, a pressure switch in some hydraulic systems comes into operation when the hydraulic pressure drops to a cut-in pressure value. Pressure switches are also used in aircraft starting systems and engine-hour meters.