Linearization of differential pressure integral silicon transducer

Claim 2

A differential pressure integral silicon transducer comprising a mounting member enclosed by a pair of restrained-edge silicon diaphragms and completely filled with a pressure transmitting fluid, said silicon diaphragms each having at least one integrally formed semiconductor strain gage that exhibits a variable Resistance as said diaphragms flex to respectively increase and decrease the strain level in response to sensing an applied differential fluid pressure, circuit means connected to each silicon diaphragm for obtaining an individual output signal, and a difference circuit for effectively subtracting said individual output signals to obtain a more linear transducer output signal indicative of the applied differential pressure.

Claim 3

A pressure transducer according to claim 1 wherein said pressure transmitting fluid is a liquid that provides a pressure bias to said pair of silicon diaphragms.

Claim 4

A pressure transducer according to claim 1 wherein said pair of silicon diaphragms are substantially mechanically and electrically matched.

Claim 5

A pressure transducer according to claim 3 wherein said mounting member is a cylindrical tube, said pair of silicon diaphragms being circular and respectively secured to either end of said tube.

Claim 6

A pressure transducer according to claim 3 further including a pair of buffer amplifiers for respectively processing each individual output signal, said difference circuit being a differential amplifier.

Claim 7

A pressure transducer according to claim 1 wherein each of said silicon diaphragms includes at least four of said integrally formed semiconductor strain gages, and said circuit means includes unitary low resistance connection areas and contact pads on each silicon diaphragm connected with said strain gages as a unitary resistance bridge circuit.

Claim 8

An integral silicon transducer for measuring low differential pressures comprising a transducer assembly including a mounting member enclosed by a pair of circular, restrained-edge silicon diaphragms and filled with a liquid providing a pressure bias thereto, said silicon diaphragms being substantially mechanically and electrically matched, and each having a plurality of integrally formed semiconductor strain gages that exhibit a variable resistance as said diaphragms flex to respectively increase and decrease the stain level in response to sensing an applied differential pressure, circuit means for connecting the strain gages on each silicon diaphragm in a resistance bridge circuit with an individual output voltage that varies nonlinearly with the applied differential pressure, and a difference circuit for effectively subtracting said nonlinear individual output voltages to obtain a more linear transducer output voltage.

Claim 9

An integral silicon transducer for measuring low differential pressures comprising a transducer assembly including a mounting member enclosed by a pair of circular, restrained-edge silicon diaphragms and filled with a liquid providing a pressure bias thereto, said silicon diaphragms being substantially mechanically and electrically matched, and each having a plurality of integrally formed semiconductor strain gages that exhibit a variable resistance as said diaphragms flex to respectively increase and decrease the stain level in response to sensing an applied differential pressure, circuit means for connecting the strain gages on each silicon diaphragm in a resistance bridge circuit with an individual output voltage that varies nonlinearly with the applied differential pressure, and a difference circuit for effectively subtracting said nonlinear individual output voltages to obtain a more linear transducer output voltage.

Claim 10

A pressure transducer according to claim 7 wherein said pair of silicon diaphragms have substantially matched individual output voltage-pressure characteristics.

Claim 11

A pressure transducer according to claim 8 further including a pair of adjustable gain buffer amplifiers for respectively processing each of said individual output voltages, said difference circuit being a differential amplifier.

Claim 12

A pressure transducer according to claim 8 wherein each of said silicon diaphragms comprises four of said integrally formed semiconductor strain gages, and said circuit means includes unitary low resistance connection areas and contact pads on each silicon diaphragm connected with said strain gages as a unitary resistance bridge circuit.