SCHRADER PRESSURE INDICATOR VALVE

Through continual checking of tyre pressure, this system:
- guarantees that passengers are safe,
- avoids emergency stops in the event of a puncture,
- reduces under-inflation and contributes to a longer tyre life,
- reduces fuel consumption by better monitoring pressure.

Monitoring of pressure when travelling is made possible by a valve housed in the wheel.
This makes the system economical and self-governing, the user only being informed in the event of a pressure problem.

The instrumented valve is housed in the same position as and instead of a standard valve.
It is compatible with classic tyre mounting techniques as long as basic mounting rules are adhered to.

The valve is fixed to the rim by a screw.
The instrumented valve supposes an additional weight of about 22 grammes.

It consists of:
- a lithium battery with a ten-year lifespan,
- a pressure sensor,
- a radiofrequency stage at 315 or 433 MHz,
- a built-in ASIC component dealing with energy management, wake-up signal when travelling or due to a change in pressure, and also with the coding of information.

The valves measure the pressure every 10 seconds when travelling and inform the vehicle every minute or immediately in the event of a sudden change.

The measurement resolution is 15 mbars and the instrumented valves monitor pressure up to 250 km/hr, from –40ºC to +100ºC, from 0 to 3.5 bars.

The vehicle is equipped with a receiver and a calculator which receives the valves’ radiofrequency information.
This information is transmitted to the vehicle calculator which continually monitors pressures and gives the alert when a pressure error is detected. This alert is sent to the instrument panel.

Each wheel has a unique identification code known to the vehicle which allow it to differentiate between the different positions of valves on the same vehicle, or valves of other vehicles.
Wheels are monitored in this way in real time.