An Oil Gauge is a device used to measure and display the oil pressure in an engine. It is typically installed in the dashboard of a vehicle or on the control panel of an industrial engine or machine. The Oil Gauge works by using a pressure sensor to measure the pressure of the oil in the engine. This pressure is then displayed on a gauge, which typically consists of a dial with a pointer that indicates the pressure in pounds per square inch (psi) or kilopascals (kPa).