Abstract: A self-standardizing pressure sensor (60) for use with an electronic fuel control system of an internal combustion engine. The sensor (60) includes a body (100) having first and second external ports (120, 122) for sensing manifold absolute pressure (MAP) and ambient atmospheric pressure (AAP), respectively. An internal valve (110) within the body (100) is biased to normally register with the MAP port (120), but is actuatable to register with the AAP port (122). The valve (110) includes an internal passage (126) which communicates whichever of the ports (120, 122) is selected to an internal pressure chamber. One wall of the chamber is defined by a flexural diaphragm (144). Flexing of the diaphragm is transmitted to an electromechanical transducer (172) which produces an output signal representative of the pressure in the internal chamber.

Abstract: Strain gauge apparatus comprises two strain sensitive piezoresistors R.sub.r1 and R.sub.t1, two op-amps, three predetermined value resistances, R.sub.a, R.sub.b, and R.sub.c, and voltage source supplying V.sub.dc. Said elements are connected to produce an output signal of the form V.sub.dc (R.sub.c /R.sub.a l ) (R.sub.r1 / R.sub.t1 -R.sub.a /R.sub.b).

Abstract: Each sensor consists of a spinel substrate in the form of a beam or a diaphragm which carries a pattern of a plurality of doped silicon piezoresistive resistors. The latter are formed from layers of doped silicon, each of which layers has been epitaxially grown on a corresponding surface of the spinel substrate. The spinel minimizes the occurrence of leakage currents with respect to the resistors, while cooperating with the silicon to provide a high degree of stress transmission to the resistors. The beam form of sensor is shown as the sensor member of a differential fluid pressure to electric signal transducer, wherein the sensor is deflected and strained in accordance with the differential pressure to be sensed.

Abstract: A probe includes a dome shaped body and at least four diaphragm pressure transducers mounted in the body with the diaphragms substantially flush with the domed surface of the body, wherein one of the transducers is mounted in the apex of the domed surface and the other transducers are spaced around the domed surface equidistant from the apex mounted transducer.Preferably the dome carries five pressure transducers, four of which are equally spaced around the cone surface.

Abstract: A semiconductor pressure transducer comprising a disc-shaped pressure-responsive diaphragm; a pair of radial strain gauge units having a piezoresistance effect, formed by injecting an impurity in the radial direction in the surface of the diaphragm; and a pair of tangential strain gauge units having a piezoresistance effect, formed by injecting an impurity in the tangential direction in the surface of the diaphragm, wherein the distance from the pair of the radial strain gauge units to the center of the circular diaphragm is greater than the distance from the pair of the tangential strain gauge units to the center of the circular diaphragm.

Abstract: A differential pressure sensor comprises a pressure-to-displacement transducer resiliently coupled to a cantilever beam strain gauge arrangement. The pressure-to-displacement transducer is provided with overrange protection permitting substantial displacement in the range of measurable pressure differentials and the more fragile cantilever beam is provided with separate overrange protection more narrowly constraining its displacement. The resilient coupling between the transducer and the beam absorbs the displacement differential. As a consequence of this structure, the device can provide high sensitivity readings in the measurable range of pressure differentials and is protected against pressure differentials greatly in excess of the measurable range.

Abstract: A digital piezoresistive pressure transducer is provided wherein a pressure differential causes the resistance of two equal, diffused piezoresistances to change by equal but opposite amounts. The variable resistance of the two piezoresistance elements is utilized to correspondingly vary the time duration of two distinct voltage levels. The ratio of the time duration of the two voltage levels bears a linear relationship to the differential pressure across the transducer that enables the various values of pressure to be determined.

Abstract: A piezoresistive differential pressure transducer in which the need for convoluted isolating diaphragms and oil fill is eliminated. The instrument as contemplated by the invention does not require O-ring seals or springs to provide over-pressure protection. The absence of convoluted diaphragms and oil minimizes inherent errors due to temperature variations and static line pressure effect.

Abstract: A differential pressure transducer assembly which indicates pressure differences while remaining insensitive to variations in line pressure and overload pressure. The assembly has a transducer consisting of a semi-conductor sensor isolated from the medium being measured by mounting it on a resilient diaphragm between two small hydraulic chambers. The chambers are closed with a pair of diaphragms which isolate the two chambers from the external environment. The transducer sensor is comprised of a silicon chip having a large center boss area which is supported by a silicon back plate of similar material fused to the silicon chip at the periphery. The back plate is mounted by a hollow support stud to a threaded hub at the center of the resilient diaphragm separating the chambers. A space between the silicon chip and back plate communicates with the hydraulic fluid of one chamber through an inlet in the support stud. The opposite side of the silicon chip is immersed in the hydraulic fluid of the other chamber.

Abstract: This invention is a high data rate pressure sensor module with an in situ calibration capability to help reduce energy consumption in wind tunnel facilities without loss of measurement accuracy. The sensor module allows for nearly a two order of magnitude increase in data rates over conventional electromechanically scanned pressure sampling techniques. The module consists of 16 solid state pressure sensor chips and signal multiplexing electronics integrally mounted to a four position pressure selector switch. One of the four positions of the pressure selector switch allows the in situ calibration of the 16 pressure sensors; the three other positions allow 48 channels (three sets of 16) pressure inputs to be measured by the sensors. The small size of the sensor module will allow mounting within many wind tunnel models, thus eliminating long tube lengths and their corresponding slow pressure response.

Abstract: A pressure sensing device is disclosed having the pressure sensing diaphragm positioned in a housing which is not stressed or enlarged by large static pressure. The housing is attached within a recess of a larger casing by means of a support diaphragm. The recesses are communicated with the interior of the housing by passages therethrough to equalize the pressure inside and outside the housing. The outer side of each casing forms a pressure reception chamber with a respective pressure receiving diaphragm. The latter chambers communicate with the recess via passages in the casing. The space between the pressure sensitive diaphragm and each pressure receiving diaphragm, including the housing interior chamber, the housing passage, the casing recess, the casing passage and the pressure receptive chamber, is filled with a fluid. The construction and filling is such that overpressure on one pressure receiving diaphram causes the entire housing to move toward the inner wall of the casing.