BSL Physics Glossary - pressure sensor - definition
This type of sensor can be on the side of a pipe carrying a liquid. When the pressure of the liquid in the pipe rises, the liquid presses the sensor out. This turns the electricity on and gives a warning on the computer to let us know that the pressure has increased in the pipe. The pressure sensor can work the other way round too. If the pressure is low in the pipe, the membrane on the sensor will be sucked in to the pipe. This will switch on the electricity supply and give a warning on the computer to let us know that the pressure has dropped in the pipe.