Pressure switches are devices that convert pressure changes into electrical or linear energy based on transducer activation. They can turn on due to pressure decrease or increase, depending on the application. The two main types of pressure switches are triggered by hydraulic or pneumatic pressure, and are available in either contact or non-contact versions. Contact means the unit is physically placed within the unit to gauge the pressure, while non-contact means the unit uses advanced technology to measure the pressure based on other types of sensors while remaining outside of the container. Hydraulic pressure switches are often used in automobiles to alert drivers of the vehicle’s fuel levels, but there are many other applications that utilize the pressure switch.