What is the working principle of a tire pressure sensor?

[Debra]

Tire pressure sensors operate differently depending on the type of tire pressure monitoring system: 1. The working principle of a direct tire pressure monitoring sensor is: It uses a wireless transmitter to send pressure information from inside the tire to a central receiver module, which then displays the tire pressure data for each tire. 2. The working principle of an indirect tire pressure monitoring sensor is: When the pressure in a tire decreases, the vehicle's weight causes the rolling radius of that wheel to become smaller, resulting in a faster rotation speed compared to other wheels. The tire pressure sensor is installed either at the valve stem position or inside the tire and is a simple tire pressure monitoring system that uses the ABS sensing function to compare the number of rotations of the tires. A tire with insufficient pressure will have a shorter circumference, and if one of the four tires has insufficient pressure, its rotation count will differ from the others during driving.