According to most of the mechanical engineers and trained mechanics, tire is considered to be the most critical part of the car. They monitor the driving of the car and are one of the most important factors as far as smooth driving is concerned. You need different types of tires if you are driving on ice as compared to what you will require while driving on rough surface. The inflation is very important. An over inflated tires as well as the under inflated tires can cause a lot of problem. Hence, it is quite important to monitor the tire pressure. They also harm the environment as they leads to lots of carbon monoxide emission from the car. Hence the tire pressure monitoring systems are used.
Up till now it is quite clear that we can monitor the tire pressure with the help of TPMS. However we also need to know that how much type of TPMS is there. But I would first like to talk about various techniques being used to monitor the tire pressure.
The first way is by using the pressure sensors. Suppose your car has four tires. Then you will require four pressure sensors. All of the pressure sensors are set to measure the real time pressure.
If any sensor shows that there is about 25% less air pressure than the normal cold tire inflation pressure then the driver will be informed and he will soon have to take some action so that this problem is solved completely.
There are one another way as well. In this method the air pressure is calculated. The velocity of each tire is also being calculated. If you have studied the physics in intermediate then you will certainly understand that what is the trick behind this method?
Suppose the velocity of one tire is found to be more as compared to the other tires. What does this mean? Actually if the tire will be underinflated then it will have to rotate more number of times to travel the same distance. Hence its velocity will be higher. This is the principle of these methods.
So these are the two ways through which you can calculate the tire pressure. The tire pressure monitoring system are developed using the above two principles. Generally there are two types of TPMS. They are the indirect and the direct one. You just get them installed in your car from some service station.