How does a tyre pressure monitoring device work?
There are a range of tyre pressure monitoring systems (TPMS) available so you should consult the vehicle manufacturer if you require a specific explanation. Basically there are two types of system, indirect systems use the fact that reduced air pressure causes the wheel to rotate at a higher speed and when this occurs an alarm is triggered. Direct systems, directly monitor tyre pressure against pre-set values and send a warning when actual pressure falls below set values. A thorough explanation is given in the RFT technology section.
