What is the principle of a car tire pressure monitor?
3 Answers
There are two principles of car tire pressure monitors: 1. Use 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. When the pressure of a certain tire decreases, the vehicle's weight will cause the rolling radius of that wheel to become smaller, resulting in its rotational speed being faster than other wheels. By comparing the difference in rotational speed between tires, the purpose of monitoring tire pressure is achieved. More information about tire pressure is as follows: 1. When the tire pressure is too high, the contact area between the tire and the ground decreases, and the contact area is inversely proportional to the pressure. The smaller the contact area, the greater the pressure the tire bears. When the tire bears excessive pressure, it will accelerate tire wear and may even cause brake failure and tire blowout. 2. When the tire pressure is too low, the contact area between the tire and the ground increases, leading to an abnormal rise in tire temperature during driving, which can easily cause sidewall deformation and reduce the tire's service life.
The working principle of tire pressure monitoring systems is actually quite simple, though I remember being amazed when I first heard about it. It mainly relies on small sensors installed inside the tires. These little devices are mounted near the tire valves and can directly measure both tire pressure and temperature. When the pressure drops below the safe threshold, the sensors send wireless alerts to the vehicle's receiver, triggering the TPMS warning light on the dashboard to remind you to inflate the tires. The science behind it is that underinflated tires increase the risk of blowouts and can even affect braking distance, which is extremely dangerous. I rely on it daily while driving, saving me considerable inspection time. Although the sensor batteries can last several years, it's important to have them checked during regular maintenance to prevent failure. Overall, this technology serves as an invisible shield for automotive safety, proving particularly useful during high-speed driving.
The principle of tire pressure monitoring systems can be divided into two types: direct and indirect. The direct type involves installing pressure sensors in each tire to measure pressure in real-time and wirelessly transmit data, triggering an alarm if the pressure falls below the set threshold. The indirect type, on the other hand, utilizes the vehicle's ABS wheel speed sensors to compare differences in tire rotation speeds to determine if the tire pressure is low—because when the pressure is low, the tire diameter decreases, causing the rotation speed to increase. I prefer the accuracy of the direct type, but the battery life is about 5-7 years and needs replacement. After installation, the system also needs calibration to ensure accuracy. The benefits include significantly improved fuel efficiency and tire lifespan, reducing tire blowout accidents by about 20%. When the tire pressure light comes on while driving, I first check the tire pressure gauge to confirm before inflating to avoid mistakes.
