Patent ID: 7584665
Filing Date: 2009-09-08
Classification: G01L

Abstract:
1. A pressure restrictor for use with a piezoresistive pressure sensing element, said element capable of providing an output upon application of a pressure to said element, said pressure restrictor, comprising: a restrictor member having a plurality of apertures symmetrically disposed about a central axis of said restrictor member directed from a first end to a second end; a pressure restrictor housing for clamping said restrictor member to said pressure sensing element at said second end, and said first end of said restrictor located in said housing for enabling said first end to receive an applied pressure and to pass said applied pressure to said second end solely through said apertures, wherein said pressure sensing element comprising: a first and a second deflecting diaphragms positioned on a common substrate, wherein the first diaphragm is positioned on said substrate to respond to an applied pressure transmitted from first end to said second end via at least one of said apertures and said second diaphragm is positioned in line with said central axis of said restrictor member and substantially isolated from said applied pressure, each diaphragm having located thereon piezoresistors arranged in a half bridge configuration, with each half bridge connected to form a full Wheatstone bridge to enable said pressure element to provide an output proportional to said applied pressure with all inertial stresses cancelled.