Abstract: An enclosed, flat covered leadless pressure sensor assembly suitable for extreme environment operation including dynamic, ultra-high temperature heating, light and heat flash, and high-speed, flow-related environments. The pressure sensor assembly comprises a substrate comprising a micromachined sensing diaphragm defined on a first side. A cover is attached to the first side of the substrate such that it covers at least the sensing diaphragm. The top surface of the cover is substantially flat, thereby promoting uniformity in the distribution of stress and thermal effects across a top surface of the cover.

Abstract: An interconnect assembly that operates in environments well exceeding 200° C. without degradation and/or failure. The interconnect assembly of the present invention eliminates the incompatible metal interfaces of the prior art and relies on aluminum first-metal wire to electrically connect to first-metal pads on a chip and a second-metal wire to electrically connect to second-metal plated contacts on a package. Both wire types are then electrically connected together utilizing a high temperature transition pad disposed between the chip and contacts on the package, therefore eliminating incompatible metal interfaces of the prior art.

Abstract: A differential pressure transducer employing a coiled tube to eliminate varying pressure fluctuations is provided. In one embodiment, a method comprises receiving, at an inlet tube of a dampening chamber, a main pressure, wherein the main pressure includes a static pressure component and a dynamic pressure component; filtering, by the inlet tube, at least a portion of the dynamic pressure component of the main pressure; outputting, from the inlet tube, a first filtered main pressure; receiving, at a volume cavity of the dampening chamber, the first filtered main pressure, wherein the volume cavity is operatively coupled to the inlet tube; filtering, by the volume cavity, at least a portion of the dynamic pressure component of the first filtered main pressure; outputting, from the volume cavity, a second filtered main pressure; and wherein the dampening chamber is tuned to a predetermined resonance frequency.

Abstract: There is disclosed a high pressure sensing header which is relatively insensitive to mounting torque. The header comprises an outer torque isolating shell which surrounds an inner “H” section header. The inner “H” section header has a thick diaphragm and is surrounded by the torque isolating shell which is secured to the “H” section header at a peripheral flange of the “H” section header. In this manner when the header is installed, the installation force is absorbed by the outer shell and there is no installation force or torque exhibited by the inner “H” section which will respond only to stress due to pressure. The torque isolating shell also contains a top surface which has a counterbore that accommodates a crush ring. When the unit is installed, the crush ring is crushed against an installation wall to enable the inner header to receive pressure without experiencing significant installation force.

Abstract: A novel flexible transducer structure is suitable for attaching to curved surface such as the leading edge of an aircraft wing. The structure comprises a thin flexible sheet of an insulating material with a leadless transducer secured to the sheet. The sheet is then placed over the curved surface and assumes the curvature of the surface. The transducer secured to the sheet provides an output of pressure according the pressure exerted on the sheet. The sheet basically is fabricated from a thin material such as Kapton and is flexible so as to assume the curvature of the surface with the transducer being exposed to pressure applied to the curved surface. The sensor in conjunction with the flexible sheet allows pressure to be measured without disturbing the air flow patterns of the measuring surfaces and because of its construction, is moisture resistant over a large variety of atmospheric conditions.

Abstract: A dual diaphragm pressure transducer, or sensor, with compensation for non-pressure effects is disclosed. The pressure sensor can include two pressure transducers located on separate portions of a chip. The first pressure transducer can be a differential pressure transducer, which produces a signal proportional to one or more applied pressures and includes other non-pressure effects. The second pressure transducer can be sealed in a hermetic chamber and thus can produce a signal proportional only to non-pressure effects. The signals can be combined to produce a signal proportional to the applied pressures with no non-pressure effects. The first and second pressure transducers can be physically and/or electrically isolated to improve sealing between the two pressure transducers and prevent pressure leaks therebetween.

Abstract: A pressure transducer assembly that uses static pressure compensation to capture low-level dynamic pressures in high temperature environments. The pressure transducer assembly combines a static-dynamic pressure transducer with a micro-filter element to achieve a compact system that can be used in extreme temperature applications where low-level, dynamic pressure measurements are required in a high pressure environment.

Abstract: A transducer comprising a filter assembly 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. 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. The filter assembly may transmit static pressure to the back of the dynamic pressure sensor to cancel out the static pressure present at the front of the sensor while removing dynamic pressure.

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 pressure transducer assembly including: a pressure sensor header; a transducer assembly member; and a joining arrangement disposed at an interface of the header and the transducer assembly member, for joining the header with the transducer assembly member, the joining arrangement including: a recessed female joining element formed in one of the header and the transducer assembly member; and a protruding male joining element formed on the other of the header and the transducer assembly member, the male joining element received in the female joining element.

Abstract: There is disclosed an internally switched multiple range transducer. The transducer employs a plurality of individual pressure sensors or Wheatstone bridges fabricated from semiconductor materials and utilizing piezoresistors. Each sensor is designed to accommodate accurately a given pressure range, therefore, each sensor is selected to provide an output when an applied pressure is within its accommodated range. As soon as the pressure exceeds the range, then another sensor is employed to produce an output. Each of the sensors, or each separate transducer, is coupled to a switch or other device to enable the selection of one of the plurality of sensors to operate within its given pressure range when the applied pressure is in that range. In this manner one obtains pressure measurements with a high degree of accuracy across a relatively large pressure range.

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: Embodiments of an ultra miniature pressure probe are disclosed. The pressure probe can include a probe body, a plurality of transducer ports, and a plurality of transducers. The probe body can be a longitudinal tubular body having a front conical end. The transducer ports can be disposed about the front end of the body. The transducers can be leadless SOI transducers, each having an active deflection area associated with a semiconductor substrate. Each transducer can be in communication with a header for supporting the transducer. The header can have a thickness substantially less than the probe diameter and can comprise a flange about an edge of the header. Each of the plurality of transducer ports can define an aperture and a counter-bore, wherein each transducer is positionable in an associated transducer port with the flange of the header of the transducer being welded to the counter-bore of the transducer port.

Abstract: A single wire interface for a transducer transmits the transducer output as a frequency modulated signal over one single wire during one interval. During a second interval a reference signal is transmitted as a frequency modulated signal. Both the transducer output and the reference signal output are processed by the same circuitry during the respective intervals to provide both frequency modulated signals. The frequencies of the two signals are measured and then the ratio of the two periods which is the reciprocal of the two frequencies is calculated. This ratio is the direct measure of the output of the transducer and when provided eliminates sources of errors.

Abstract: A system for measuring a multiplicity of pressures as those experienced by a model in a wind tunnel is depicted. The system includes individual sensor devices which are connected to an electronics module. The sensors may be connected to the electronics module via a cable in a first embodiment. In an alternate embodiment, the sensors may be connected to the electronics module via a mating connector located therebetween. A memory component which stores compensation coefficients associated with each of the sensors may also be included in the system to correct errors associated with each sensor. The advantage of the various embodiments is that each sensor does not have any compensation stored thereon and thus, the sensors can be made very small to operate at very high temperatures without any loss of accuracy.

Abstract: A single pressure sensing capsule has a reference pressure ported to the rear side of a silicon sensing die. The front side of the silicon sensing die receives a main pressure at another port. The difference between the main and reference pressure results in the sensor providing an differential pressure output. The reference pressure or main pressure may be derived from a pump pressure which is being monitored. The pump pressure output is subjected to a pump ripple or a sinusoidally varying pressure. In order to compensate for pump ripple, a coiled tube or an adjustable dampening chamber comprising a spiral inlet tube and a volume cavity can be used. The tube length is selected to suppress the pump ripple as applied to the sensor die. In this manner, the pump ripple cannot cause resonance which would result in pressure amplification and which pressure amplification would destroy the sensor.

Abstract: Systems and methods for a two lead electronic switch adapted to replace a mechanical switch are provided. In one embodiment, a method comprises, in an electronic switch having a sensor, an electronic circuit, a first terminal and a second terminal, receiving, by the electronic circuit, from the sensor, a sensed voltage proportional to an amount sensed by the sensor; operating the electronic circuit in a first state when the sensed voltage is greater than or equal to a threshold voltage associated with a threshold pressure sensed by the sensor; operating the electronic circuit in a second state when the sensed voltage is less than the threshold voltage associated with the threshold pressure sensed by the sensor; receiving, across the first terminal and the second terminal, an input voltage used to provide power for the electronic switch; and wherein the first terminal and the second terminal are also used to couple the electronic switch to a device.

Abstract: A pressure transducer assembly, and a method of making the same, comprising a header having a first connection portion; a port having a corresponding second connection portion, wherein the first connection portion of the header is attached to the second connection portion of the port to create a header-port interface; and an integral back up ring defined in one of the header and port, wherein the integral back up ring is separated from the header-port interface by a cavity. The first connection portion of the header is attached to the second connection portion of the port by a full penetration weld and the integral back up ring is adapted to block the full penetration weld from damaging the header and thus minimize, if not eliminate, crack propagation.

Abstract: A transducer assembly configured to accommodate a plurality of individually tunable sensing elements of various geometries and configurations by using a cap and an accompanying capillary tube. The configuration of the various embodiments described herein eliminate the header to flat plate welds of the prior art, and therefore better accommodates a plurality of sensing elements and corresponding header assemblies within one transducer assembly.

Abstract: A pressure belt comprising a flexible belt, and a flat pack assembly removably attached to the flexible belt, wherein each flat pack assembly comprises at least one sensing element. Further, each flat pack assembly also comprises a memory component associated with the sensing element thereon, wherein the memory component houses data specific to the corresponding sensing element. Unlike prior art structures, each flat pack assembly is individually removable. Therefore, if one sensing element malfunctions, it may be replaced by removing the flat pack assembly comprising the malfunctioning sensing element and swapping it out for a flat pack assembly comprising an operable sensing element. This is an improvement over the prior art as it eliminates the need for replacing and recalibrating the entire pressure belt when one sensing element malfunctions, which can be both time consuming and costly.