Media compatible pressure transducer

An absolute pressure transducer, comprising:

• (a) a wafer of a semiconductor material having a top and bottom surface with relatively thin side surfaces, said bottom surface having first and second circular recesses adjacent one another and relatively of the same diameter manifesting a first and second diaphragm area,
• (b) a base plate secured to said bottom surface to cover said recesses with said base plate having an aperture communicating solely with said second circular recess,
• (c) a first piezoresistive circuit arrangement mounted on said top surface of said wafer above said first depression with a peripheral sensor located near an edge of said recess and a central sensor located near the center of said recess,
• (d) a second piezoresistive circuit arrangement mounted on said top surface of said wafer above said second recess with a peripheral sensor located near an edge of said recess and a central sensor located near the center of said recess,
• (e) means for applying a reference pressure to said top surface of said wafer,
• (f) means for applying another pressure to said aperture in said base plate for directing the same solely to said second recess, and
• (g) means coupling said piezoresistive sensors in a circuit arrangement to cause said circuit to provide an output indicative of said another pressure as referenced to said reference pressure.