Pressure switch

How does a pressure switch work?

A pressure switch works either mechanically or electronically and opens or closes the switch contact depending on the measured pressure of a medium. Pressure switches are often used with pumps, valves or boosters and have the task of keeping the pressure within a predefined span, without exceeding the upper or lower limit.

Mechanical pressure switches are inexpensive instruments based on mechanical measuring principles such as Bourdon tubes, diaphragm elements or diaphragm-piston measuring systems. The corresponding measuring element triggers the mechanical switch contact in the pressure switch. On switching, the mechanical pressure switch sends an electrical signal. The special feature of the mechanical pressure switch is that no further supply voltage is required for the electrical signal, which protects the application from failures.

An electronic pressure switch consists of a pressure sensor, a digital pressure display and an electronic switch and it performs the functions of switching, transmission and display in just one instrument. The function of the electronic pressure sensor is to convert the measured pressure into an electrical signal. When the preset pressure is reached, the electrical circuit opens or closes. In the case of an electronic pressure switch, functions such as delay time, switch point, reset point and hysteresis, among others, can be programmed, whereby the switch points and also the output signal can be adapted to the application-specific requirements. The electronic pressure switch also provides a continuous pressure display for monitoring the switching outputs and thus also serves as a digital pressure gauge