The pressure sensor detects the level of force (pressure) on a surface or device and converts that information into an electrical signal. This information can then be displayed as usable data for users to interpret. These sensors are used in many different industrial applications including hydraulic, pneumatic, and automotive systems as well as in medical equipment like ventilators and spirometry devices that measure lung capacity.
The basic working principle is that a diaphragm or piston moves due to the applied pressure and this physical deformation is measured by the sensor. There are two general types of pressure sensors: mechanical and electronic. Mechanical pressure sensors use a piston or diaphragm and they are mechanically converted into an electrical signal by a strain gauge that is either glued or deposited onto the membrane. The strain gauges are made of silicon (monocrystalline, polysilicon thin film, or bonded metal foil) and they have an increased resistance due to strain.
These sensors have an MTTF that is expected to be hundreds of years and they are very reliable. Electronic pressure sensors do not have any mechanical parts that wear out and they are typically resistant to vibration and corrosion.
Some of the most important key specifications for a pressure sensor include max pressure rating, overpressure protection, and temperature range. The maximum pressure rating is the highest amount of pressure that the sensor is designed to operate reliably at without damage. The overpressure protection option is an additional feature that is used to protect the sensor from excessive pressure that could rupture the device. The sensor will provide a warning when the pressure is approaching the max limit.