Tyre pressure monitoring system

Michelin has launched a wireless and battery-free tyre monitoring system that marks the commercial debut of UK-developed pressure sensor technology. The global tyre giant's eTire II sensor patch, designed for use on trucks and other commercial vehicles, monitors the pressure and temperature of tyres via surface acoustic wave (SAW) technology licensed from Oxfordshire-based Transense Technologies.

The system uses the unique physical properties of SAWs to take continuous measurements and transmit the readings via an integrated radio frequency identification tag. At 11g and the thickness of a few sheets of paper, the sensor patch is small and lightweight enough to be embedded in the interior of a tyre's sidewall without affecting the wheel balance.

Because SAW monitoring is a passive technology the Michelin system requires no power source, eliminating the need to periodically remove wheels and change batteries. This also boosts the system's environmental credentials compared with other products, say its developers.In the eTire system, the measurements taken by the sensor are read at the vehicle's depot or a drive-by unit by a hand-held device that retrieves the data automatically. Fleet operators can also track the performance of their tyres via the internet.

Source: theengineer.co.ukAdded: 5 January 2007