Abstract: The invention relates to a boundary layer probe for determining a fluid flow, comprising a measuring surface which is formed on a probe wall and with which a fluid flow to be determined is in contact during a measuring operation. The boundary layer probe also comprises an assembly of measuring obstacles that are formed in the region of the measuring surface as obstacles which disrupt the fluid flow in a flow region adjacent to the measuring surface, each of which has an elongated obstacle course extending over a particular obstacle length, and which are arranged at substantially equidistant angular distances in the circumferential direction. The boundary layer probe additionally has pressure measuring points, each of which is radially adjacent to an associated obstacle in order to detect a local pressure in the region of the measuring surface. The invention additionally relates to a measuring assembly and to a method for determining a fluid flow.

Abstract: The present disclosure relates to an air-speed sensor, system and monitoring process This sensor generally comprise a sensor casing having a leading surface and distinctly oriented input ports. Each input port can independently capture respective air pressure and connects to a pressure sensor that independently measures that air pressure digital processor connects to each pressure sensor and can digitally compute pressure ratios between the input ports and compare these ratios against designated pressure ratios corresponding to designated incident airspeed angles of incidence to output an airspeed incident angle and airspeed accordingly.

Abstract: A pressure probe affixable in a scale three-dimensional model of direct environment, buildings, and other objects and having a plurality of orifices open in circumferential spaced apart relation on a probe side surface each connected through a dynamic pressure flow path to a plurality of pressure sensors each of which generates a pressure signal which varies based on change dynamic pressure at a corresponding one of the plurality of orifices which pressure signals can be analyzed to determine fluid flow direction and fluid flow speed of a fluid flow about the pressure probe affixed in the scale three-dimensional model.

Abstract: There is disclosed a fluid sensor for measuring the pressure of a fluid, the fluid sensor comprising: a surface; a recess formed at the surface, the recess being configured to affect the pressure of the fluid flowing at the recess, at least one ambient sensor port for measuring ambient fluid pressure at the surface, and at least one recess sensor port for measuring the fluid pressure at the recess.

Abstract: Described herein is a sensor probe for association with a portion of an aircraft. The sensor probe includes a microphone assembly having a portion configured to receive audio signals. The sensor probe further includes a nosecone associated with the microphone assembly. The nosecone assembly is configured to shield the portion of the microphone assembly from noise generated by direct impact of an airflow for a plurality of local flow angles.

Abstract: A hybrid heater system for an aircraft air data sensor includes a voltage source and a first hybrid heater set. The first hybrid heater set includes a carbon nanotube (CNT) heater, a first positive temperature coefficient (PTC) heater disposed in parallel with the CNT heater to form a parallel formation, and a second PTC heater disposed in series between the voltage source and the parallel formation.

Abstract: A sensor includes an airfoil body, a heater element, and a temperature probe. The airfoil body defines a sensor axis, an insulating cavity, and extends between a leading edge and a trailing edge of the airfoil body. The heater element extends axially within the airfoil body and is positioned between the leading edge and the trailing edge of the airfoil body. The temperature probe extends axially within the airfoil body, is positioned between the heater element and the trailing edge of the airfoil body, and is separated from the heater element by the insulating cavity to limit thermal communication between the temperature probe and the heater element. Gas turbine engines, methods of making sensors, and methods of thermally separating temperature probes and heater elements in sensors are also described.

Abstract: An angle of attack (AOA) sensor system is disclosed. The system comprises a plurality of pitot tube ports in a housing. The pitot tube ports include a set of positive angle pitot ports, a set of negative angle pitot ports, and a central pitot port. The central pitot port is aligned with a central chord line of a wing of the aircraft. A plurality of pitot tubes communicate with the plurality of pitot tube ports (at a first end), and with a plurality of pressure sensors (at a second end). A microcontroller is configured to generate a respective current AOA value for each pressure sensor based on a respective ram pressure measurement generated by each of the pressure sensors, and generate an AOA measurement of the aircraft by comparing each respective current AOA value to respective calibrated AOA values stored in a memory.

Abstract: A pitot tube cover for a pitot tube operable to determine a speed of an aircraft based on an airstream impinging on the pitot tube. The pitot tube cover has a body and a sail extending from the body. The body has a top surface opposite a bottom surface, an elongate cavity and a slot extending from the top surface to the elongate cavity, the elongate cavity sized to receive the pitot tube and the slot having a width narrower than a diameter of the pitot tube to provide a retaining force which retains the body on the pitot tube after the pitot tube is received by the elongate cavity. The sail includes a first substantially planar sail surface and a second substantially planar sail surface extending from the first sail surface distally to the body.

Abstract: A probe head of a pitot probe includes a mandrel having a helical groove, a heater within the helical groove of the mandrel such that an exterior surface of the heater is flush with an exterior surface of the mandrel, and an outer shell having an interior surface in air-tight contact with the mandrel and the heater.

Abstract: An aircraft probe includes a base, a strut that extends from the base, at least one port, and an electronics assembly insertable into the strut and removable from the strut. The electronics assembly includes at least one pressure sensor that is pneumatically connected to the at least one port to sense a first pressure when in the inserted position.

Abstract: One embodiment is an apparatus including an inner reference tube associated with a load-bearing rotating shaft and having a first set of teeth associated therewith and disposed around a periphery thereof; an outer reference tube associated with an input gear and disposed about the inner reference, the outer reference tube and having a second set of teeth associated therewith and disposed around a periphery thereof wherein teeth comprising the second set of teeth are interleaved with teeth comprising the first set of teeth to comprise an interleaved set of teeth and wherein the inner reference tube and the outer reference tube rotate about a same longitudinal axis and at a same speed as the rotating shaft; and a sensor system comprising a first variable resistance sensor (“VRS”) configured to detect a presence of successive teeth of the interleaved set of teeth and generate an output signal indicative thereof.

Abstract: A total air temperature sensor includes a nose having an airfoil cross section with a leading edge and trailing edge, a sensor housing spaced from and downstream of the nose defining a stagnation chamber with at least one inlet, and a temperature sensor positioned within the sensor housing.

Abstract: A system for determining aircraft performance for at least one flight phase includes a first terminal (11) comprising connections to a first, second and third repository respectively comprising at least a first set of data files (22) a second set of executable scripts (23) and a third set of configuration files (17). At least the third set of configuration files is arranged to be accessed via a second user interface of a second terminal (18). The system further comprises a calling module (12) arranged for selecting, based on the input parameters received and the configuration file selected, at least one executable script file (23) for processing the associated data files (22) so as to determine by a calculation engine (26) the performance of the aircraft for the least one flight phase.

Abstract: The present invention includes an adjustable Pitot tube and method for using the same for operating or flight testing an aircraft comprising: a Pitot probe; a streamline tube connected to the Pitot probe; a mount on the aircraft connected to the streamline tube, wherein the streamline tube can at least one of rotate about an axis of the mount, or the streamline tube can move the Pitot probe closer to, or away from, a skin of the aircraft.

Abstract: A system, a method and an apparatus for autonomous monitoring, detecting and tracking of at least one of movement and orientation of a body or portion of a body. The apparatus comprises a device configured to monitor the translational movement and/or rotational movement of the body; and an altimeter including at least one pair of opposed high sensitivity sensors configured to measure changes in height of the body. An alert condition is determined based on the translational and/or rotational movement of the body and changes in height of the body or portion of the body. The alert condition may comprise a hard fall event, a soft fall event, a susceptibility to a fall, or a near fall event.

Abstract: Systems and methods for additive manufacturing for air data probes are provided. In at least one embodiment a probe comprises a support structure comprising one or more ports for receiving one or more fluids, the support structure comprising an endoskeleton mandrel having an opening for receiving a fluid; and a heating cable encircling an external surface of the endoskeleton mandrel. The probe also comprises an additive coating fused to the external surface of the endoskeleton mandrel and an external surface of the heating cable; and an internal assembly inside the support structure for carrying pressures from the one or more ports to one or more instruments that respond to the one or more fluids to provide a measurement.

Abstract: An air data probe includes a probe head and a raised portion. The probe head defines a longitudinal axis and includes a forward tip and a probe head surface. The raised portion is defined in the probe head surface aft of the forward tip. The raised portion is raised radially relative to the probe head surface. The raised portion is configured and adapted to trip a fluid boundary layer passing over the probe head to transition from laminar to turbulent for reducing boundary layer separation for consistent readings at high altitudes and/or high mach numbers. A method of manufacturing an air data probe includes forming a probe head and applying a raised portion to a surface of the probe head aft of the forward tip. Applying the raised portion to the surface of the probe head includes using brazing, additive manufacturing, adhesives and/or any other suitable technique.

Abstract: A method of repairing an air data probe sense port includes inserting a plug into a sense port in an air data probe, mounting the plug to the air data probe, dressing the welded plug to be substantially flush with adjacent air data probe surface, and forming a new sense port in the air data probe. The method can include enlarging the sense port prior to inserting the plug therein.

Abstract: A protective cover for a pilot probe of an aircraft comprising a first tubular member formed of a rigid material, and a second tubular member formed of a rigid material, and a second tubular member formed of a flexible material including a first ply disposed on an inner side of the first tubular member, having an opening at a first end thereof for receiving the leading end of a pilot probe therein and a closed second end, and a second ply disposed on an outer side of the first tubular member, having a first end thereof secured about the first end of the inner ply and a second end secured to the second end of the first ply.

Abstract: A pressure sensor has a sensor body at least partly formed with an electrically insulating material, particularly a ceramic material, defining a cavity facing on which is a diaphragm provided with an electric detector element, configured for detecting a bending of the diaphragm. The sensor body supports a circuit arrangement, including, a plurality of circuit components, among which is an integrated circuit, for treating a signal generated by the detection element. The circuit arrangement includes tracks made of electrically conductive material directly deposited on a surface of the sensor body made of electrically insulating material. The integrated circuit is made up of a die made of semiconductor material directly bonded onto the surface of the sensor body and the die is connected to respective tracks by means of wire bonding, i.e. by means of thin connecting wires made of electrically conductive material.

Abstract: An air data probe includes a probe head. The probe head defines a longitudinal axis with a forward tip and aft base and includes a wall tap port inlet defined in the probe head aft between the forward tip and the aft base. The wall tap port inlet opens on an angle relative to the longitudinal axis, wherein the wall tap port inlet has an elongated inlet perimeter configured to resist the formation of a meniscus, or otherwise reduce moisture induced pressure errors.

Abstract: A nose section for a heated air pressure probe includes a barrier having a wall which blocks the direct longitudinal intake of air from an inlet, and diverts the air through one or more bypass ports. A heater is located in the barrier. Both the wall and the heater are located near the front of the inlet.

Abstract: An air data sensor that determines a body's angle of attack, static air pressure, total air pressure, mach number, static air temperature and true air speed in one device using pressure and temperature readings. The air data sensor includes a probe that protrudes into an airflow to collect data, a base plate for attaching the probe to a body, and an electronics housing including electronics for interpreting the data collected from the probe.

Abstract: A surface-mounted fuselage skin appliqué panel having an aperture to a reference static air input port is rugged, replaceable, and independently calibratable. The static port skin appliqué generally conforms to the fuselage surface, and is held in place either with adhesive or with a mounting frame. The appliqué size enables airflow in the vicinity of the static port to be substantially uniform. Because the appliqué is not part of the fuselage structure, distorting stress loads are avoided. The appliqué material resists scratches and bumps that can distort flow. A static port skin appliqué and its mounting provisions can be made using a range of materials, and can receive finishes to meet user preferences.

Abstract: A method and a device for obtaining the three components (u,v,w) of the air speed (TA) of an aircraft along its flight path, the device including an arm (2) provided with two pressure probes disposed at each of its ends, each probe having two pressure intakes.

Abstract: A method of calculating a system level air data parameter for an aircraft, for example aircraft angle-of-attack (AOA) and/or angle-of-sideslip (AOS), includes measuring a plurality of local static pressures pi. Next, a plurality of non-dimensional pressure ratios are each generated as a function of one of the plurality of local static pressures pi, a predicted system static pressure Pspredicted, and a predicted impact pressure qc predicted. Then, the system level air data parameter is calculated as a function of the generated plurality of non-dimensional pressure ratios. Air data systems having air data computers configured to implement the method are also disclosed. The air data systems can be Flush Air Data Systems (FADS), or other types of air data systems.

Abstract: A multi-function air data sensing probe has a strut that is mounted on an aircraft and extends laterally from the aircraft skin. The strut is supported on a base plate, and has a pitot pressure sensing tube at the outer end thereof, with a pitot port facing upstream, and also includes a passageway for total air temperature sensor including a forwardly facing inlet scoop that leads to a chamber in the strut that is laterally offset from the inlet scoop so that flow changes direction as it enters the chamber. The surface defining the change of direction between the scoop and the chamber is provided with bleed holes for bleeding off boundary layer air. A vane type air data sensor is mounted on a shaft that rotates freely and is supported on the strut, and is positioned to sense the relative air flow past the strut to determine changes of relative angles of such air flow. In addition, the strut has static pressure sensing ports on lateral sides thereof leading to a separate chamber on the interior of the strut.

Abstract: A system and method for advanced warning of severe weather for general aviation aircraft is presented. An aircraft includes an onboard weather tracker which monitors atmospheric condition changes. The weather tracker uses data from an onboard barometric altimeter and a GPS device to calculate air pressure changes in order to identify when the aircraft is flying into a low-pressure zone. The weather tracker uses the air pressure's rate of change and the aircraft's speed to determine the criticality of a situation and appropriately notifies a pilot. The weather tracker provides the pilot with local airport information and alternative flight pattern information per the pilot's request.

Abstract: A cover for a pitot-static probe includes a braided head resistance sleeve insertable over the probe that has an open end provided with an annular fold carrying a retaining ring for establishing a compressive fit with a non-tapered portion of the probe and accommodating relative movements of the sleeve in response to ground conditions without dislodging.

Abstract: A multi-function air data sensing probe has a strut that is mounted on an aircraft and extends laterally from the aircraft skin. The strut is supported on a base plate, and has a pitot pressure sensing tube at the outer end thereof, with a pitot port facing upstream, and also includes a passageway for total air temperature sensor including a forwardly facing inlet scoop that leads to a chamber in the strut that is laterally offset from the inlet scoop so that flow changes direction as it enters the chamber. The surface defining the change of direction between the scoop and the chamber is provided with bleed holes for bleeding off boundary layer air. A vane type air data sensor is mounted on a shaft that rotates freely and is supported on the strut, and is positioned to sense the relative air flow past the strut to determine changes of relative angles of such air flow. In addition, the strut has static pressure sensing ports on lateral sides thereof leading to a separate chamber on the interior of the strut.

Abstract: A transducer for measuring the relative velocity of movement of a body in a liquid or gaseous medium employs no reciprocating parts and functions by sensing the force applied to a diaphragm (6) die to its movement through the medium or the movement of the medium towards the diaphragm. The speed transducer makes use of a Hall effect solid state device (7) that produces an output when a magnetic field is applied to either of its surfaces. The level of the output voltage is proportional to the velocity of movement in the positive direction, i.e. when the force acts on diaphragm (6) in (FIG. 1). Since the transducer takes into account differential forces, an unwanted common force acting on both diaphragms simultaneously will have no effect on the measured speed. The tubular body (1) in which the Hall effect device is located may be made from any non-magnetic material suitable for the environment in which the transducer will be used.

Abstract: A boat mounted speedometer for providing a speed signal to a boat operator. The system includes a probe that reaches a laminar flow of water below the back edge of the boat. An opening in the probe allows for water pressure, proportional to boat speed to build up in the system. Any air trapped in the water in the system is bled out through a bleed valve. A pressure transducer reads out a signal and a processor generates a digital signal proportional to pressure and speed of the boat. The signal is read out for the operator on a back lit digital speedometer display.

Abstract: A system and method for estimating parameters of multiple tones in an input signal. The method includes receiving samples of the input signal, generating a frequency transform (FT) of the samples, identifying multiple amplitude peaks in the FT corresponding to the tones, and determining parameter estimates characterizing each of the multiple tones based on the peaks. For each tone, the effects of the other tones are removed from the FT of the peak of the tone using the parameter estimates of the other tones to generate modified FT data for the tone. Single tone estimation is applied to the modified FT data to generating refined parameter estimates of the tone, which is used to update the parameter estimates of the tone. After refining the estimates for each tone, the entire process may be repeated one or more times using successive refined estimates to generate final estimates for the parameters.

Abstract: An air data sensing probe such as a multi-function probe includes a barrel having multiple pressure sensing ports for sensing multiple pressures. Instrumentation coupled to the pressure sensing ports provides electrical signals indicative of the pressures. An inertial navigation system input of the probe receives electrical signals indicative of inertial navigation data for the aircraft. A neural network of the probe receives as inputs the electrical signals indicative of the multiple pressures and the electrical signals indicative of the inertial navigation data. The neural network is trained or configured to provide as an output, electrical signals indicative of an air data parameter.

Abstract: A pneumatic pressure line cleaning assembly for clearing the pneumatic lines of a pressure gauge, specifically a speedometer for a power boat, is attached to a cut tube of the pneumatic line between the pressure gauge and the air intake opening with a second port of a three-port valve being connected in flow communication with the pressure gauge and a third port opening of the three-port valve being in flow communication with the pressure intake opening. The first port of the three-port valve is in flow communication with an air compressor. In normal operating conditions, ports two and three of the three-port valve are in flow communication so that the pressure gauge pneumatic line is in flow communication with the pressure intake opening and in a second position, the three-port valve is positioned so that the third-port is in flow communication with the first port. In the second position, the air compressor is actuated to provide pressurized bursts of air in a direction towards the air intake opening.

Abstract: Device for pressure tapping, integrated into the fuselage of an aircraft, comprising an integrated plate (10), without discontinuity, with a pressure tapping part in the center (16). The plate (10) enters a supplementary opening (22) formed in a fuselage panel (20). The plate (10) and the panel part (20) surrounding the opening (22) are fixed on a supporting element (18) linked to the framework of the aircraft (34, 36). In the case where rivet, screw or bolt type fixations are used, they are placed at the edge of the plate (10). This arrangement facilitates assembly and improves the precision of the measurement, by suppressing any discontinuity in the measurement zone.

Abstract: A standoff arm and probe assembly for a helicopter has a standoff mounting arm that extends outwardly from the helicopter body in a selected direction, preferably forwardly. The standoff arm has an outer end that mounts a low lateral speed sensing probe that is positioned with an axis substantially parallel to the axis of a helicopter rotor, and within the downwash region of air movement causes by the rotor. The low lateral speed sensing probe has ports that are arranged annularly around the probe, and the pressures sensed at selected annular or peripheral locations on the probe are measured to determine low air speeds. Additionally, the standoff arm can mount a plurality of other sensors such as a pitot pressure probe extending forwardly from the arm, a lateral pressure sensing probe along a lateral side of the arm, and the arm can mount outside air temperature sensors, ice detectors, and total air temperature sensors, if desired.

Abstract: A flame and heat resistant cover for a pitot-static probe has an open end for easy placement over said probe and a gathered end for covering the ram port of the probe. The cover consists essentially of a braided tube of fiber threads and having an open end formed by folding over an end of said tube to form a pocket for receiving a coiled spring carrying an internal annular reinforcing ring having a diameter outwardly engaging the spring to establish initial tensioning and establishing a normal minimal opening therefor, and inwardly engaging the spring to limit the maximum opening therefor. The open end is treated with an impact resisting elastomeric saturant that impregnates said fibers for increasing the abrasion resistance of said fibers during insertion of said cover over said probe. The cover may be formed of flame resistant fibers including heat treated glass fibers and para-aramid fibers.

Abstract: The fluid flow meter of the present invention includes a ramp inclined to the surface of a vessel so as to form a recess in the surface. A dynamic port surface extends from the lower end of the ramp to the surface of the vessel. A dynamic port is formed in the surface of the vessel, and a static port is formed in the ramp. The differential pressure between the dynamic and static ports is measured and is related to the flow velocity of fluid over the surface. The inventive flow meter has advantages of reduced drag, reduced likelihood of fouling and reduced likelihood of impact damage compared to conventional flow meters.

Abstract: A flight velocity vector measuring system in a wide velocity region in which an attack angle pressure coefficient C&agr; of air current, a sideslip angle pressure coefficient C&bgr; and an air current angle pressure coefficient C&ggr; are obtained from five pressure information detected by a square truncated pyramid-shape probe. The aforementioned pressure coefficients, pressure calibration coefficients with respect to a Mach number M, an attack angle &agr; and a sideslip angle &bgr; every velocity region obtained by dividing the wide velocity region into a plurality of regions stored in advance in the calculation processor, and a Mach number M, an attack angle &agr; and a sideslip angle &bgr; of unknown quantity constitute a calculation processing expression comprising a polynomial approximation to call the pressure calibration coefficients in the velocity region, and flight velocity vectors (M, &agr;, &bgr;) are calculated by the polynomial approximation.

Abstract: A method and apparatus for evaluating the end cap round transducer horn assemblies used in debubbling operations wherein the ECR THA can be evaluated off-line at both high and low power and on-line by making electrical measurements on the ECR THA. The electrical measurements are used to characterize the physical condition of the piezoelectric ceramics of the THA. A test box is employed to practice the method. The test box is connected between the THA and a signal analyzer. Power is supplied to the THA and the electrical signals across the THA are sampled. The sampled electrical signals are transmitted to the signal analyzer while maintaining the amplitude and phase relationship thereof. The sampled electrical signals are used to generate an impedance trace for the particular THA. That impedance trace is compared to a model impedance trace. In such manner, it can be determined whether the ECR THA is operational.

Abstract: A method for operating a cheese-producing textile machine (1), having a plurality of aligned work stations (2), a transport device (21) extending over the length of the machine for removing finished cheeses (11), and a cheese changer (23) displaceable above the work stations with an ultrasound sensor device (30) connected to the control device (38) of the cheese changer (23) for monitoring the loading state of the transport device (21). The sensor device (30, 38) is initially set to the climatic conditions of the respective place of employment by processing appropriate reference sound signals, i.e. a correction factor is determined. During operation, scanning values (TW) are then determined by means of the traveling time of the measuring sound signals of the ultrasound sensor (30) which, taking into consideration the respectively prevailing climatic conditions, permit conclusions regarding the loading state of the transport device (21) in the deposit areas of the respective work station (2).

Abstract: An ultrasonic probe includes an ultrasonic transducer; a delay line acoustically coupled to said transducer so that ultrasonic vibrations may be transmitted into said delay line from said ultrasonic transducer in a first direction, said delay line includes a first section and a second section; the first and second sections forming an interface that is substantially perpendicular to said first direction; and the second section including a surface for coupling with a material to be investigated. The probe can be used to measure a thickness of a coating on a substrate by transmitting a signal in a first direction from the transducer into the delay line; measuring a time t.sub.1 for a first portion of the signal to travel round trip from the transducer and the interface; using the measured time t.sub.1 to calculate an expected time t.sub.2 for a second portion of the signal to travel round trip from the transducer to an opposite face of the delay line; measuring a time t.sub.

Abstract: The recreation of vibration levels at certain points in a stationary vehicle interior that are representative of realistic road conditions are achieved using road measurements in conjunction with a technique known as "reciprocal filtering." The reciprocal filtering technique consists of using an inverse transfer function, or impulse response in the time domain, between an excitation transducer and an accelerometer to calculate the excitation signal needed to recreate the vibrations measured on the road when squeak and rattle are present in a component of the vehicle. A set of excitation signals may be recorded for each component in the vehicle which is suspected of producing squeak and rattle noise. When a complaint is made that a vehicle is producing squeak and rattle, a service technician may reproduce noise by inducing vibrations through a kit having a CD player, an amplifier, a bass shaker and a CD with the set of excitation signals stored on separate tracks thereof.

Abstract: A method and apparatus for evaluating the end cap round transducer horn assemblies used in debubbling operations wherein the ECR THA can be evaluated off-line at both high and low power and on-line by making electrical measurements on the ECR THA. The electrical measurements are used to characterize the physical condition of the piezoelectric ceramics of the THA. A test box is employed to practice the method. The test box is connected between the THA and a signal analyzer. Power is supplied to the THA and the electrical signals across the THA are sampled. The sampled electrical signals are transmitted to the signal analyzer while maintaining the amplitude and phase relationship thereof. The sampled electrical signals are used to generate an impedance trace for the particular THA. That impedance trace is compared to a model impedance trace. In such manner, it can be determined whether the ECR THA is operational.

Abstract: A method and apparatus for evaluating the end cap round transducer horn assemblies used in debubbling operations wherein the ECR THA can be evaluated off-line at both high and low power and on-line by making electrical measurements on the ECR THA. The electrical measurements are used to characterize the physical condition of the piezoelectric ceramics of the THA. A test box is employed to practice the method. The test box is connected between the THA and a signal analyzer. Power is supplied to the THA and the electrical signals across the THA are sampled. The sampled electrical signals are transmitted to the signal analyzer while maintaining the amplitude and phase relationship thereof. The sampled electrical signals are used to generate an impedance trace for the particular THA. That impedance trace is compared to a model impedance trace. In such manner, it can be determined whether the ECR THA is operational.

Abstract: A magnetic accelerometer detects the sharp lateral rocking movements of an unbalanced spinning tub of a washing machine. The accelerometer has a fixed and a movable magnet that are disposed at a rest position in spaced, magnetic attraction to each other. The movable magnet breaks away from the stationary magnet in response to vibration forces of a predetermined magnitude and frequency. When the magnet breaks away, it presses against an actuator button of a miniature switch and therefore signals an alarm condition. When the vibration forces are reduced below the trigger level, the movable magnet is pulled back to its rest position by magnetic attraction with the stationary magnet. The magnetic attraction of the stationary and movable magnets can be adjusted and the break away point can be set by applying an external magnetic field to the magnets.

Abstract: A digital bond tester operating at frequencies in the kHz range and relying upon vibrational modes which can excite all or substantial portions of the test object.

Abstract: A method and an apparatus for detecting and measuring cracks in plate-like structures using acoustic emission technique are disclosed. A false aperture transducer is designed to provide a criterion for filtering out extraneous noise in the acoustic emission signal based on modal analysis by computing the ratio of the high-frequency peak amplitude to low-frequency peak amplitude of the signal. A calibration curve correlating crack depth to the amplitude ratio can be obtained by simulating crack growth in a fracture specimen coupled to a test structure or field structure, and measuring acoustic emission signal in the structure by the false aperture transducer. The calibration curve correlates simulated crack depth percentage with computed peak amplitude ratio of the measured signal.