A pressure switch is a form of switch that closes an electrical contact when a certain set pressure has been reached on its input. The switch may be designed to make contact either on pressure rise or on pressure fall.The pressure switch may be fixed or adjustable, by moving the contacts or adjusting tension in a counterbalance spring. Industrial pressure switches may have a calibrated scale and pointer to show the set point of the switch. A pressure switch will have a differential range around its setpoint in which small changes of pressure do not change the state of the contacts. Some types allow adjustment of the differential.

• A pressure switch will have a differential range around its setpoint in which small changes of pressure do not change the state of the contacts. Some types allow adjustment of the differential.