A pressure sensor transforms physical pressure into a measurable electrical output. Its core working principle begins with a sensing element that deforms or changes property under pressure. Common designs use a diaphragm, which flexes when pressure differs between two sides. This mechanical movement is then converted into an electrical signal.

In piezoresistive sensors, strain gauges are bonded or diffused on the diaphragm. When pressure bends the diaphragm, the gauges stretch or compress. Their resistance changes in proportion to strain. A Wheatstone bridge converts this tiny resistance change into voltage. Signal conditioning amplifies and linearizes the output.

Capacitive pressure sensors use two conductive plates. One plate is a flexible diaphragm, and the other is fixed. Applied pressure moves the diaphragm, changing the gap between plates. Since capacitance depends on distance, the capacitance varies with pressure. Electronics measure this change and convert it into a pressure reading.

MEMS pressure sensors integrate tiny diaphragms and circuits on silicon, offering small size and high accuracy. Most sensors measure absolute, gauge, or differential pressure. Absolute references a vacuum, gauge references atmosphere, and differential compares two ports.

Temperature compensation and calibration ensure reliable results. Pressure sensors are used in automotive, medical, industrial, and environmental systems. They enable monitoring, control, and safety. They aid decisions.