We all know that when a tire runs out of air, its circumference will change. Therefore, the wheel speed sensor can analyze the difference in the speed of the four tires. If the tire runs the same distance, the circumference of the flat tire will become longer. The number will be reduced, and when the difference is large, the trip computer will issue an alarm for abnormal tire pressure.
　　Each sensor is built into the tire near the valve port. The original one is built with the valve. Each individual sensor is powered by a battery. The measured tire pressure value is wirelessly transmitted to the receiver and then displayed.
　　The principle of this type of tire pressure monitoring is similar to that of the first type, except that the sensor is not hidden in the tire, but screwed on like a valve cover, just like the wireless tire pressure gauge used when inflating, except that it is also powered by the battery. The sensor's power supply is transmitted wirelessly, and it will be displayed after the receiver receives it.