Abstract: A two or three axis load cell capable of measuring axial and one or more shear forces is disclosed. The load cell can comprise a force collector connected by one or more connecting rods to one or more cross pieces. The load cell can comprise a single cross piece and can measure an axial force applied to the load cell and at least one component of shear force applied to the load cell. In other embodiments, the load cell can comprise two cross pieces, disposed at disparate angles, to enable the measurement of an axial force and both components of shear force applied to the force collector. The cross pieces are equipped with a means, such as piezoresistive elements to measure their deflection due to the applied forces on the force collector. The connecting rods can be fitted with additional piezoresistors to measure the axial forces on the force collector.

Abstract: A pressure transducer assembly for measuring pressures in high temperature environments employing an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter is operative to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer. The acoustic filter operates to absorb acoustic waves resultant from the hot gases, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation.

Abstract: A pressure transducer comprising a corrosion resistant metal diaphragm, having an active region, and capable of deflecting when a force is applied to the diaphragm; and a piezoresistive silicon-on-insulator sensor array disposed on a single substrate, the substrate secured to the diaphragm, the sensor array having a first outer sensor near an edge of the diaphragm at a first location and on the active region, a second outer sensor near an edge of the diaphragm at a second location and on the active region, and at least one center sensor substantially overlying a center of the diaphragm, the sensors connected in a bridge array to provide an output voltage proportional to the force applied to the diaphragm. The sensors are dielectrically isolated from the substrate.

Abstract: It is an object of the present invention to provide a pressure transducer having a header wherein the header is comprised of a first section and a second section that are offset from each other. Each first and second section has a flexible diaphragm adapted to receive a first and second pressure, respectively. A central channel connects the diaphragms and a pressure sensor, located within the central channel, communicates with the channel and produces an output equal to the difference between the first and second pressures. The resultant device is a low differential pressure transducer which enables one to bring leads from the sensor out while having diaphragms of substantially the same size and diameter, therefore enabling the diaphragms to exhibit the same back pressure and be equally compliant.

Abstract: A gage pressure transducer comprising a first pressure sensing assembly exposed to a main pressure and a second pressure sensing assembly exposed to a reference pressure. The pressure sensing assemblies comprise half-bridge sensors and means for using an alignment glass plate with each sensor which reduces the amount of oil required for operation, which consequently reduces the back pressures caused by large volumes of oil. The pressure sensor assemblies are hermetically sealed using glass frits, therefore enabling the gage pressure transducer to robustly and accurately measure pressure in harsh environments.

Abstract: A filter assembly for use with a static-dynamic piezoresistive pressure transducer that measures low amplitude, dynamic pressure perturbations superimposed on top of a high static pressure through the implementation of a low-pass mechanical filter assembly is disclosed. The filter assembly may comprise a dual lumen reference tube and a removable filter subassembly further comprising a porous metal filter and narrow diameter tube. The transducer, which may be capable of operating at ultra-high temperatures and in harsh environments, may comprise of a static piezoresistive pressure sensor, which measures the large pressures on the order of 200 psi and greater, and an ultrasensitive, dynamic piezoresistive pressure sensor which may capture small, high frequency pressure oscillations on the order of a few psi or less.

Abstract: A combined wet-wet differential transducer and a gage pressure transducer located in the same housing, comprising a semiconductor chip which comprises a gage sensor chip on one section and a differential sensor chip on a second section. Each sensor chip has a Wheatstone bridge comprising piezoresistors and is responsive to an applied pressure. The gage chip and the differential chip are placed in a header having a front section and a back section adapted to receive a first and second pressure, respectively. The sensors are in communication with first and second pressure ports such that the absolute sensor provides an output indicative of a pressure applied to a first port and the differential sensor provides an output indicative of the pressure difference between the first and second pressure ports.

Abstract: It is an objective of the present invention to provide a pressure transducer assembly for measuring pressures in high temperature environments that employs an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer.