Patent ID: 7151337
Filing Date: 2006-12-19
Classification: G01L

Abstract:
1. A pressure monitor comprising a base having a rigid frame; a simply lid secured to the base to define with the base a substantially fluid tight chamber, at least part of the lid being flexible and forming a diaphragm which will deflect in response to changes in the fluid pressure surrounding the monitor; means for transmitting movement of the diaphragm to a distortable substrate located within the chamber, wherein such means are located remote from the edge of the frame, the distortable substrate having a first SAW device mounted thereon, and at least a second and a third SAW device mounted on a non-distortable reference substrate section within the chamber, said second SAW device having its direction of propagation inclined at an angle to the direction of propagation of at least one of said first and third SAW devices, said distortable substrate being formed by a first region and said reference substrate section by a second region of a single substrate, wherein movement of the diaphragm induced by a change in pressure in the zone surrounding the monitor results in distortion of the distortable substrate, which is measurable by the SAW device mounted thereon, without distorting said reference substrate section.