Vehicle wireless sensing and communication system

摘要

A valve stem assembly for a tyre has an elongate metallic (eg brass) valve stem 7, a rubber body 23 attached to the end of the stem 7 within the interior space of the tyre and a sensor capsule 24 within the rubber body 23 which includes a SAW absolute pressure sensor 27,29' in a chamber 25 in flow communication with the inside of the tyre and also a SAW temperature sensor 28,28' in another chamber 26 isolated from the inside of the tyre by a flexible or rigid membrane 31,33.