Abstract: In an improved strain gage for measuring pressure differentials within areas of varying pressure there is provided a flexible sapphire diaphragm having disposed thereon a Wheatstone bridge. The diaphragm being attached to a base portion by way of a glass bonding material. The base portion's function being to support the flexible diaphragm without interfering with the measurement of strain. The diaphragm having a recess extending to a predetermined depth thereby defining a recessed area having a peripheral edge in order to create pressure points at the peripheral edge of the recess adjacent the recessed area of the diaphragm.