Abstract: A circuit for a fluxgate magnetometer includes a plurality of digital function blocks that are programmed as functions within a microcontroller. The microcontroller includes and implements the functions of an analog circuit to lower the cost and complexity of a digital fluxgate magnetometer circuit.

Abstract: A strain gauge sensor system and method for measuring the strain in a member, such as a fiber rope, has a sensor target assembly having a plurality of magnets carried spaced apart by individual gauge lengths along the member. Position and trigger sensor devices are configured spaced apart along side a desired path of travel of the member. When the member is fed along the desired path of travel, the trigger sensor device, in response to magnetically sensing a passing magnet, triggers the position sensor device to read the position of an adjacent passing magnet. The strain in the gauge length is determined from the read position. RFID tags placed on the member between the magnets can be identified by an RF reader to identify a particular gauge length being measured. The system can include a deployment device for feeding the member along the desired path.

Abstract: An apparatus (10) is set forth for measuring a return signal of a magnetostrictive sensor (20) that detects a force, torque, or pressure. The return signal includes noise, a DC resistance (44), an AC resistance and an inductance and the inductance is shifted ninety degrees from the AC resistance. The apparatus (10) includes a sensor filter (22) to remove the noise from the return signal. A sensor filter (22) shifts the return signal and more specifically, the inductance by an additional angle and the sum of the additional angle and the ninety degrees phase shift is defined as the final detection angle. To detect the inductance at the final detection angle, a wave filter (16) and a reference filter (28) shifts a reference signal by the final detection angle to trigger a first demodulator (26) to detect the inductance at the final detection angle. The inductance detected by the first demodulator (26) varies due to temperature.

Abstract: A load detector is constructed so as to stabilize an output voltage responding to an input load. The load detector includes a magnetostrictive sensor which includes a hollow case, a coil housed in the case, and a rod-like magnetic member located at an axial center of the coil, magnetized by an electric current flowing through the coil and receiving a load at an end thereof. The load detector further includes a pin which has a contact surface for applying the load onto the end of the magnetic member and is disposed axially inline with the magnetic member, and a bearing collar for reducing displacement of the pin with respect to the magnetic member. The magnetostrictive sensor and the pin are fitted, facing each other, into the bearing collar. The load detector is utilized suitably for transport equipment such as a water vehicle or electric bicycle.

Abstract: A sensor has a substrate having a mechanically deformable region, a magnetostrictive spin-valve sensor element being arranged to detect a mechanical deformation of the mechanically deformable region. On the substrate, there is a device for generating a controllable magnetic field by which a performance of the sensor element is influenced.

Abstract: A method for producing a stress impedance effect element, the method including: connecting opposite ends of a magnetostrictive amorphous thin wire and respective electrodes by ultrasonic bonding; forming a groove in an elastic thin substrate having a thermal expansion coefficient equal to that of the magnetostrictive amorphous thin wire; installing the magnetostrictive amorphous thin wire in the groove; and bonding together the magnetostrictive amorphous thin wire and the elastic thin substrate by applying an insulating adhesive across the magnetoresistive amorphous thin wire.

Abstract: In a method of measuring stress/strain by detecting Barkhausen noise, an exciting/sensing device is arranged at least adjacent to a magnetic or magnetizable element, and passing an increasing magnetizing current through the exciting device. The start of the Barkhausen noise in the element, as a function of the magnetizing current is detected by the sensing device, and the magnetizing current at that time represents a measurement of the stress/strain condition of the element.

Abstract: In a master carrier for magnetic transfer which comprises a support that has a transfer-recording pattern arrayed in the track direction thereof in accordance with the information to be transferred to a magnetic recording medium, and a magnetic layer formed on the transfer-recording pattern of the support, the in-plane distance L (mm) between the hill and the valley of the warped master carrier, the vertical-direction distance H (?m) between the two, and the thickness d (mm) of the master carrier are so defined that they satisfy a relation of 0.05?H·d3/L?0.6.

Abstract: A magneto-elastic torque sensor and system include a substrate and a magneto-elastic sensing component formed from or on the substrate. The magneto-elastic sensing component and the substrate together form a magneto-elastic torque sensor, which when subject to a stress associated with a torque, shifts a characteristic frequency thereof linearly in response to the torque, thereby inducing a pathway by which magneto-elastic energy is coupled to excite vibrations in a basal plane of the magneto-elastic sensor, thereby generating torque-based information based on a resonant frequency thereof.

Abstract: This publication discloses a method and arrangement for determining the hardening depth of steel or other ferromagnetic substances without breaking the object being measured. According to the invention, a varying magnetic field, which causes magnetic Barkhausen noise (MBN), is created in the measurement object with the aid of a magnetization coil 13. The varying magnetic field is regulated in such a way that the maximum force of the magnetic field does not exceed the coercitive force of the unhardened part of the measurement object. The MBN caused is measured with the aid of an MBN sensor. The measured signal is filtered and Fourier transformed. The signal in the frequency range is integrated over a suitable frequency band, in order to determine the value depicting the energy of the MBN. This value correlates with the hardening depth and on the basis of this value it is thus possible to determine the hardening depth.

Abstract: A device is provided by which the stiffness coefficient of a flexure, in either a pitch or roll direction, can be measured while a slider is mounted thereon and while the flexure and slider are in a loaded condition as might be obtained during normal operational conditions of a HGA in a HDA. There are two methods of making the measurement, a static method in which the slider is loaded by an external weight called a pendulum and the angular displacement of the slider is measured, and a dynamical method in which the pendulum is caused to oscillate while in contact with the slider and its natural and loaded frequencies of oscillation are measured.

Abstract: A sensor device for examining the surfaces of a work piece, in particular in regard to burrs, is provided wherein said device comprises a probe shaft having a detector head with at least one inductive element, wherein said at least one inductive element couples inductively to the work piece, and wherein the at least one inductive element is constructed and arranged in such a manner that, with respect to a longitudinal axis of the probe shaft, the detector head has a field of view surrounding the probe shaft.

Abstract: A sensor assembly for measuring force along an axis (F) comprises an inductance coil extending around the axis (F) for establishing a loop of magnetic flux looping axially through the coil and extending around the axis (F) to define a donut shaped ring of magnetic flux surrounding the axis (F). A core of magnetostrictive material provides a primary path for the magnetic flux in a first portion of the loop of magnetic flux and a magnetic carrier provides a return path for magnetic flux in a second portion of the loop of magnetic flux as the magnetic flux circles the coil through the core and the carrier. A first interface extends radially between the core and the carrier whereby the core and the carrier are urged together at the interface in response to a force applied parallel to the axis (F). Various embodiments or combinations of the core and carrier are illustrated in FIGS. 3–7.

Abstract: A sensor for measuring mechanical changes in length, in particular a compressive and/or tensile stress sensor, includes a sandwich system with two flat and superposed electrodes separated from each other by a tunnel element (tunnel barrier), in particular an oxide barrier, a current being set up between the electrodes and through the tunnel barrier, one electrode consisting of a magnetostrictive layer 3 which responds to elongation, and wherein the contributions of the anisotropies caused by mechanical tension are larger than those from the intrinsic anisotropies, relative changes in system resistance ?R/R larger than 10% at room temperature being attained during elongation.

Abstract: A system and method are provided for detecting cracks and their location in a structure. A circuit coupled to a structure has capacitive strain sensors coupled sequentially and in parallel to one another. When excited by a variable magnetic field, the circuit has a resonant frequency that is different for unstained and strained states. In terms of strained states, the resonant frequency is indicative of a region of the circuit that is experiencing strain induced by strain in a region of the structure in proximity to the region of the circuit. An inductor is electrically coupled to one end of each circuit. A magnetic field response recorder wirelessly transmits the variable magnetic field to the inductor and senses the resonant frequency of the circuit so-excited by the variable magnetic field.

Abstract: A magnetic force sensor assembly for a workholding fixture includes a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture. The magnetic force sensor assembly also includes a sensor operatively supported by the base of the component to sense a position change of the magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base.

Abstract: Observability of damage precursor, damage and usage states, or event occurrence may be enhanced by modifying component materials to include self-monitoring materials or by processing test material to alter the surface properties. The properties of the self monitoring materials, such as magnetic permeability or electrical conductivity, are monitored with electromagnetic sensors and provide greater property variations with component condition than the original component material. Processing includes shot peening or laser welding.

Abstract: Systems and methods of measuring residual stress are disclosed. In one embodiment, a method of measuring residual stress in a material under test includes directing radiation onto a stressed material and detecting the resulting diffraction peaks to measure known residual stress of a control specimen, inducing and sensing magnetoelastic interactions onto the control specimen, developing an empirical database of the diffraction and magnetoelastic interaction measurements of the control specimen, inducing and measuring magnetoelastic interactions on a material under test, and correlating the empirical database to the magnetoelastic interaction outputs from the material under test.

Abstract: A magnetostrictive strain sensor (10) includes a magnetostrictive core (12) comprising a magnetostrictive material, such as a nickel-iron alloy, able to conduct a magnetic flux and whose permeability is alterable by application of a strain. A conductive coil (14) is proximate the magnetostrictive core (12) to generate the magnetic flux when electrically excited. A shell (16) surrounds the conductive coil (14) and the magnetostrictive core (12) for providing a conductive return path for the magnetic flux. An excitation source (18) is electrically connected to the conductive coil (14) for electrically exciting the conductive coil (14) with an alternating current having a constant magnitude. An in-phase voltage circuit (22) is electrically connected across the conductive coil (14). The in-phase voltage circuit (22) senses an in-phase voltage that is in-phase with the alternating current. The in-phase voltage varies correspondingly to the strain subjected to the magnetostrictive core (12).

Abstract: A force transducer element (20) comprises a body (22) of magnetisable material having at least one magnetised region (30) at an angle, say 45°, to the force-sensing direction (P—P). Preferably there are a plurality of parallel magnetised regions of alternating opposite polarity of magnetisation to form closed loops (43p, 43n). The element may be a block having opposite force receiving surfaces (24, 24?). The body (122) may contain plural transducer elements (120a, 120b) angled to one another to resolve force directions. The principle is extended to a circular transducer element (243). The invention may be implemented in a flexible magnetic tape. Another embodiment (300) is realised in a planar structure in which a ferromagnetic core (310) is subject to a magnetic field (326) at an angle to the direction (F) of force application generated by laterally offset coils (312, 314). A sensor device (330) is fabricated in the structure.

Abstract: A sensor arrangement for detecting mechanical forces (F) with at least one magnetic-field-dependent sensor element, in which the output signal of the sensor element depends on the deflection of a mechanical component in the magnetic field in response to the exertion of force. The mechanical component here is a spring, which changes its location in the magnetic field in response to the exertion of force and is a component of a brake system for a motor vehicle; the at least one sensor element being located in the force flow of the brake caliper.

Abstract: The present invention seeks to provide a novel load cell which measures the force applied to, for example, an oarlock, without alteration to the boat and with minimal requirements for installation, use and maintenance. The force sensing system comprises (i) a force sensor, (ii) a load member to which a load is applied and (iii) a support member contacting a support, the force sensor deflecting when transmitting a force between the load member and the support member; wherein the load member and support member are concentric tubes and form, with the force sensor, a unitary assembly.

Abstract: A force sensor, or a method, determines a force using at least a measured inductance in a coil wherein a quantum tunneling composite is located in a magnetic path created by the coil, is positioned in a load path of the force, and is under strain from the force. A strain sensor, or a method, determines a strain using at least a measured inductance in a coil wherein a quantum tunneling composite is located in a magnetic path created by the coil, is positioned in a load path of a force, and is under strain from the force.

Abstract: The invention provides a load detecting system comprising a core (83) of magnetostrictive material, a coil (85) disposed in the vicinity of the core, and a load detecting circuit (10) connected to the coil (85) for detecting the magnitude of a load acting on the core (83). The load detecting circuit (10) comprises an exciting circuit (102) for passing an a.c.

Abstract: The present invention is directed to a method of sensing pressure in which applied pressure causes a change in the magnetization vector of a magnetoresistive layer within the device and a corresponding change in resistance. The method includes providing a sensing device with a sensor including plurality of layers, the plurality of layers comprising a non magnetic conducting layer disposed between a magnetoresistive layer with non-zero magnetostriction and a ferromagnetic biasing layer. Once provided, the method then includes sensing a resistance in the plurality of layers upon application of pressure to the sensing device, the applied pressure causing the magnetization vector of the magnetoresistive layer to change and thereby result in a change in resistance.

Abstract: A force sensor, in particular for detecting the forces on a vehicle seat, includes a force measurement cell (1) that has a Hall element. The force measurement cell (1) includes at least one bending bar (2, 3), which from the exertion of force to be detected exeris an influence on the magnetic field in the region of a magnetic-field-sensitive sensor element (6) of the measurement cell (1). The sensing is done with a Hall element (6), held on the at least one bending bar (2, 3), which element, under the force exerted on the bending bar (2, 3), can be deflected in the field of a relatively stationary permanent magnet (4), and a magnetic diagnosis field in the region of the Hall element (6) can be generated whose field lines are located in the plane of the sensor element without influencing the measurement field.

Abstract: In a railway line, thermally-induced stresses are a factor for both rail breaks and rail buckling. These stresses are in the longitudinal direction. A nondestructive measuring technique enables the residual stress in a rail to be determined, and hence the thermally-induced stress. An electromagnetic probe is used to measure the stresses in the rail web in the vertical direction, and in the direction parallel to the longitudinal axis. The residual stress in the longitudinal direction can be deduced from the measured stress in the vertical direction; hence the thermally-induced stress can be determined.

Abstract: A non-contact rotation speed and torque sensing device which uses the natural inhomogeneities in the magnetic properties of a rotating element (4) to measure movement, displacement and deformation of the rotating element. An alternating magnetic field is applied in the region of a rotating element (4) and a signal representing the change in magnetic flux caused by the inhomogeneities of the magnetic structure of the object is received at a sensor (1). By processing the sensed signal using the auto-correlation function, the speed of rotation of the element (4) may be determined through inspection of the periodicity of the signal.

Abstract: A sensor device having a magnetostrictive force sensor is provided. To detect a force, the sensor device contains a TMR force sensor element having a magnetic detection layer of material having a magnetostriction coefficient ??|5·10?6|, a magnetically harder reference layer, and a tunnel barrier disposed between these layers. Established in the detection layer is a starting magnetization that relative to the magnetization of the reference layer, which is directed in the direction of force, forms an angle of other than 0° and thus is rotated out of its starting position under the effect of the force.

Abstract: The invention provides a load detecting system comprising a core (83) of magnetostrictive material, a coil (85) disposed in the vicinity of the core, and a load detecting circuit (10) connected to the coil (85) for detecting the magnitude of a load acting on the core (83). The load detecting circuit (10) comprises an exciting circuit (102) for passing an a.c.

Abstract: A strain sensor includes a sensor section having a magnetic material provided on one surface of a conductor, the magnetic material being formed integrally with the conductor and having a magnetic strain constant with an absolute value larger than 1×10?7, a fixing mechanism which fixes at least a part of the sensor section, an inductor disposed in a surface side of the sensor section which is opposite the surface on which the magnetic material is provided, the inductor being disposed opposite and away from the sensor section, and a detection unit which detects the amount of deformation of the sensor section caused by stress applied thereto on the basis of a change in inductance of the inductor.

Abstract: A magnetostrictive strain sensor includes a Hall effect sensor for measuring the change in magnetic flux a magnetic circuit including a magnetostrictive element. A strain sensing apparatus includes one or more magnetic elements defining a magnetic circuit having a gap, and including a magnetostrictive element adapted to receive a load force. A Hall effect sensor is disposed within the gap for sensing a change in magnetic flux in the magnetic circuit. The Hall effect sensor may include a programmable circuit for zeroing and calibrating the sensing apparatus, and for providing temperature compensation. The magnetostrictive element may be magnetized to form the magnetized element, and may be formed from material known as TERFENOL-D.

Abstract: An improved method of sensing strain allows measurements of stress, torque, vibration and other loads imposed on a body without physical contact between the body/sensor and the monitoring equipment. An induction loop is at least partially comprised of a magnetostrictive material with a non-linear current-voltage relationship. An excitation device such as a coil is used to induce an AC response in the sensor. The non-linear response to the induced current is received by a sensing device such as a sensing coil, and the output thereof is filtered. The excitation device and sensing device are located in operative proximity to the sensor, but need not be in contact therewith, allowing easy measurement in small spaces, under harsh conditions, or of moving bodies such as drive shafts. The non-linear response of the sensor induces easily detectable harmonics of the base frequency of excitation. These harmonics may advantageously be measured as well.

Abstract: A stress or magnetic field sensor comprising a generally elongate magnetically soft amorphous or nanocrystalline electrically resistive element and biasing means for applying to the element a bias magnetic field of which the component directed along the length of the sensor has an amplitude variation pattern along the element. A periodically varying pattern has the effect of reducing the sensitivity of a stress sensor to external ambient fields (FIG. 3 shows that with a sawtooth bias field the sensitive portions a of a sensor move to positions b in the presence of an ambient field, but their number remains the same). A ramped bias field enables the position of the sensitive region of the sensor to be controlled, for measuring local stress, or for mapping an external magnetic field. Control of the regions where the sensor is active may include selective conductive coating of portions of its length.

Abstract: The present invention relates to a force sensing device, and in particular to a force sensing device for sensing an oscillating force or for application as a filter. In general terms, the invention proposes a force sensing device having a magneto electric material and a magnetic element moveable relative thereto in response to an applied force. The magneto electric material is exposed to the magnetic field of the magnetic element which has a magnetisation direction parallel to the direction of the movement.

Abstract: The present invention relates to a proximity sensor system comprising a sensor generating two types of pulse signals having opposite polarities in order to detect two different, small, metallic objects and to distinguish the objects. The proximity sensor system can involve at least two metallic objects to be detected having different magnetic properties; a sensor comprising a magnetic core having a plurality of legs and a toroidal coil winding fitted and supported onto at least one of the legs of the magnetic core; and an electronic circuit processing output signals from the sensor. The sensor generates predetermined signals having opposite polarities when metallic objects pass in proximity to the sensor. Suitable metallic objects include those made of ferromagnetic metal and diamagnetic or paramagnetic metal.

Abstract: Stress in the wall of a pipe (12) is measured using a pig (10) carrying at least one linear array of probes, so that the probes (30) in the array pass in succession over a location on the pipe wall. Each probe (30) comprises an electromagnetic core (32) with two spaced apart electromagnetic poles (34), and a magnetic sensor (36) arranged to sense the reluctance of that part of the magnetic circuit between the poles (34), and an alternating magnetic field is generated in the electromagnet means and consequently in the pipe wall. Successive probes (30) in the array are oriented differently so that the corresponding orientations of the magnetic field in the pipe wall are different. Preferably the probes (30) also include sensors (38) between the two poles (34) to sense magnetic flux perpendicular to the direction of the free space magnetic field between the poles. The signal from the sensor (36) and (38) enable the stress to be determined. Such an array may be used with any long object of ferromagnetic material.

Abstract: A force sensor, in particular for detecting the forces on a vehicle seat, with a force measurement cell (1) that has a Hall element is proposed. The force measurement cell (1) includes at least one bending bar (2, 3), which from the exertion of force to be detected exerts an influence on the magnetic field in the region of a magnetic-field-sensitive sensor element (6) of the measurement cell (1). The sensing is done with a Hall element (6), held on the at least one bending bar (2, 3), which element, under the force exerted on the bending bar (2, 3), can be deflected in the field of a relatively stationary permanent magnet (4), and a magnetic diagnosis field in the region of the Hall element (6) can be generated whose field lines are located in the plane of the sensor element without influencing the measurement field.

Abstract: A semiconductor magnetic sensor includes a semiconductor substrate, a source, a drain, a gate, and a carrier condensing means. The source and the drain are located in a surface of the substrate. One of the source and the drain includes adjoining two regions. The gate is located between the source and the drain for drawing minority carriers of the substrate to induce a channel, through which the carriers flow between the source and the drain to form a channel carrier current. The carriers flow into the two regions to form two regional carrier currents. The magnitude of a magnetic field where the sensor is placed is measured using the difference in quantity between the two regional carrier currents. The carrier condensing means locally increases carrier density in the channel carrier current in the proximity of an axis that passes between the two regions in order to increase the difference.

Abstract: The invention relates to a method for measuring mechanical stresses of a rotating part (1) in an essentially closed metal housing. The rotating part comprises a sensor (2) which reflects electromagnetic waves and which can be measurably deformed as a result of a mechanical stress exerted on said rotating part (1). The two antennas (A1, A2) receiving the reflected signals of the sensor (2) are arranged in the bearing housing (10) in such a way that they cannot rotate in relation to the sensor and are distanced (&agr;). Said antennas emit receiving signals (a1,a2) which are sent to an electronic evaluation system (20,21) which measures the mechanical stresses of the rotating part (1) on the basis of both receiving signals (a1,a2).

Abstract: Methods and systems for controlling motion of and optically tracking a mechanically unattached probe (202) in three-dimensions are disclosed. A mechanically unattached magnetic probe (202) is placed in the system under test. The position of the probe is optically tracked in three dimensions by sensing light scattered by the probe and direct light from a light source. Magnetic poles (200) positioned about the probe are selectively magnetized to control motion of the probe in three dimensions by minimizing error between a sensed position and a desired position. In one implementation, the coil currents are time division multiplexed such that the average force on the probe produces motion in a desired direction.

Abstract: A sensor device having a magnetostrictive force sensor is provided. To detect a force, the sensor device contains a TMR force sensor element having a magnetic detection layer of material having a magnetostriction coefficient &lgr;≧|5·10−6|, a magnetically harder reference layer, and a tunnel barrier disposed between these layers. Established in the detection layer is a starting magnetization that relative to the magnetization of the reference layer, which is directed in the direction of force, forms an angle of other than 0° and thus is rotated out of its starting position under the effect of the force.

Abstract: A sensor arrangement for detecting mechanical forces (F) with at least one magnetic-field-dependent sensor element, in which the output signal of the sensor element depends on the deflection of a mechanical component in the magnetic field in response to the exertion of force. The mechanical component here is a spring, which changes its location in the magnetic field in response to the exertion of force and is a component of a brake system for a motor vehicle; the at least one sensor element being located in the force flow of the brake caliper.

Abstract: Several embodiments of electric power assisted manually operated devices wherein the manual input force is sensed by a sensor that does not require lost motion connections and significant movement in order to determine the force applied. Also a compact drive is disclosed that permits the application to winding drums such as fishing reels. In addition a simplified temperature compensation system for the sensor is employed. Thus, the arrangements can be easily utilized with conventional structures with minimum change.

Abstract: Disclosed is a method for the nondestructive metal characterization and the measurement of stress in the interior of a ferromagnetic part under test by means of measuring a high-frequency electric signal caused by flowing an excitation current through the part under test and/or by the mechanical deformation of the part under test. The present invention is distinguished by the electric potential of the part under test being detected by means of direct or indirect electric tapping on said part under test or a region of said part under test and a high-frequency potential component, which is used as the high-frequency noise signal for determining test parameters, is determined from the electric potential of the part under test caused by changes in magnetization processes.

Abstract: A system (200) monitors a load associated with a load carrying member. The system (200) may include a voltage divider (240) and a computer device (250). The voltage divider (240) measures inductance associated with load sensing elements (210) that monitor the load carrying member. The computer device (250) determines displacements of the load sensing elements (210) based on the inductance associated with the load sensing elements (210) and determines the load associated with the load carrying member based on the displacements of the load sensing elements (210). The system may be designed to be portable and/or DC powered.

Abstract: A magnetostrictive force sensor universally usable in any environment with similar signals unaffected by the surrounding material. To this end, a sensor comprising a shaft of magnetostrictive material with an inductance coil wound around the shaft is provided with a magnetic shell enclosing the coil only or both the coil and the shaft. Upon application of the magnetic field, the resultant flow of magnetic flux is confined to a path through the shaft and the magnetic shell. By confining the magnetic flux path, the dependency of the sensor signal on the surrounding material and environment is essentially eliminated.

Abstract: A stress or magnetic field sensor comprises a generally elongate magnetically soft amorphous or nanocrystalline electrically resistive element and biasing means for applying to the element a bias magnetic field of which the component directed along the length of the sensor has an amplitude variation pattern along the element. A periodically varying pattern has the effect of reducing the sensitivity of a stress sensor to external ambient fields (FIG. 3 shows that with a sawtooth bias field the sensitive portions a of a sensor move to positions b in the presence of an ambient field, but their number remains the same). A ramped bias field enables the position of the sensitive region of the sensor to be controlled, for measuring local stress, or for mapping an external magnetic field. Control of the regions where the sensor is active may include selective conductive coating of portions of its length.

Abstract: A tension sensing assembly for a seat restraint system in a vehicle includes a sensor plate adapted to be fixed relative to vehicle structure and a movable anchor plate adapted to be connected to belt webbing and movable relative to the sensor plate. The tension sensing assembly also includes a housing mounted to the sensor plate and a movable actuator disposed in the housing. The tension sensing assembly includes at least one spring disposed between the housing and the actuator. The tension sensing assembly further includes at least one magnet and a Hall effect sensor mounted to either one of the housing and the actuator. The anchor plate has a tab portion extending through the housing and cooperable with the actuator to move the actuator to deflect the at least one spring.

Abstract: A method for determining a “safe-operation” point for a metal structural element subjected to repeated loading, the same or different, generating variable levels of strain and residual stress in the worked element; and, predicting the imminent failure of the structural element. The surface of the metal element is worked to provide a residual strain, for example, by shot-peening. Measurements of electrical conductivity are compared at various chosen frequencies corresponding to different depths in the “near-surface” of the element. Similar measurements are made in the near-surface of a “standard” and a first difference is computed between the conductivity of the shot-peened surface and the “standard” surface. This first difference provides a basis for comparison of the effects of residual stress after successive loadings of the shot-peened metal element.