Patent ID: 6715355
Filing Date: 2004-04-06
Classification: B60C,G01L

Abstract:
A pressure monitoring system comprising a first pressure chamber and a second pressure chamber separated by a diaphragm, a first surface acoustical wave (SAW) device having a first resonant frequency mounted on one side of the diaphragm and a second SAW device having a second resonant frequency mounted on the other side of the diaphragm, the first chamber being arranged to be pressurized to a predetermined pressure P1 and to remain at that pressure and the second chamber being arranged to initially be pressurized to a pressure P2 equal to pressure P1 but being subject to change over time, whereby if the pressure P2 in the second chamber falls or rises relative to the pressure P1 in the first chamber, the diaphragm will deflect so one side thereof is subject to tension and the other side thereof is subject to compression, the first and second SAW devices being arranged to sense this deflection by sensing said tension and compression and hence provide an output indicative of the change of the pressure P2 in the second chamber relative to the pressure P1 in the first chamber and wherein the system provides wireless communication between the system and a remote sensor.