Abstract: Methods and systems for determining a change in condition of a rock bolt. Some methods may comprise, at a first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a first time of flight for each of the shear and longitudinal waves, at a second point in time after the first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a second time of flight for each of the shear and longitudinal waves, and using the relative changes of the first and second time of flights, determining the change in condition of the rock bolt section.

Abstract: The present disclosure provides an Anderon meter for cryogenic environment including a housing; a control arm installed on an inner circumference of the housing rotatably relative to the housing, and including a pressing portion; and a clamp including a contact portion on a side and an assembly portion on an opposite side, wherein the contact portion is in contact with the pressing portion so that the contact portion is pressed by the pressing portion, and the assembly portion is coupled to an inner circumference of the bearing by interference fit, wherein the pressing portion presses the contact portion by the control of an amount of relative rotation of the control arm and the assembly portion is coupled to the inner circumference of the bearing by interference fit to determine friction characteristics between the inner race of the bearing and the assembly portion.

Abstract: Technologies are described herein for enabling the automated testing of remote control units by providing a suitable test station. The test station includes features that allow it to interact with the remote control units inputs, such as buttons and microphone, and outputs, such as IR and RF remote control codes, status LEDs, and audio output. The test station may be controlled by a controller that executes test scripts or other routines that exercise the functionality of the remote control unit as desired.

Abstract: The present invention discloses a piezoelectric patch-based real-time and high-precision bolt preload detection method and system. A piezoelectric patch is used as an ultrasonic excitation source and pasted on the head of a bolt, and the high-precision fitting relationship between the ultrasonic change of time-of-flight and the bolt preload is established according to the law of the ultrasonic change of time-of-flight of single echo with the stress so that the real-time detection of the bolt preload is realized by using the mathematical relationship. Compared with the previous method using ultrasonic probes, the present invention eliminates the error caused by the uncertainty of couplant thickness and further improves the measurement precision by using the change of time-of-flight of single echo. Meanwhile, the low-error rate measurement of the bolt preload is realized at a low cost and without affecting the structural performance.

Abstract: Provided are a material testing machine and a gripping force detecting method that can easily judge whether a test piece is gripped with an appropriate gripping force by a gripper. A controlling section is connected to a FFT transforming section via a load cell; the FFT transforming section calculates a natural frequency of a system comprising a test piece and an upper gripper which is connected to a load cell based on a detected value of a force of the load cell. In addition, the controlling section is connected to a storing section which stores the natural frequency calculated by the FFT transforming section. Furthermore, the controlling section is also connected to a comparing section which compares the natural frequency calculated by the FFT transforming section and the natural frequency stored by the storing section before a test starts.

Abstract: A method of measuring an axial force of a bolt may include fastening a joint using a fastener, receiving a vibration signal by a detector, transforming the received vibration signal into frequency domain data having a plurality of frames, analyzing the signal transformed into the frequency domain data, and predicting an axial force and indicating a predictive value thereof.

Abstract: A method for measuring a preload of a fastener is described. The method, which may be practiced at least in part by an apparatus, includes establishing an initial value associated with an absence of the preload of the fastener and providing an adapter and a transducer rotatably coupled to the adapter. The transducer may be positioned in contact with the fastener. The transducer is caused to direct an incident ultrasonic wave to the fastener and to receive a reflected ultrasonic wave from the fastener. Data associated with the incident ultrasonic wave and the reflected sonic wave is used to generate a modified value associated with the preload of the fastener, and the preload of the fastener is calculated based on a difference between the initial value and the modified value.

Abstract: A method for operating a fuel injection system with pressure reduction, and a fuel injection system that includes a fuel injection valve with a servo valve are provided. The method for operating a fuel injection system includes performing a desired pressure reduction in the pressure accumulator using at least one fuel injection valve of the fuel injection system. This is achieved by opening a servo valve in the fuel injection valve, which is opened, during a pressure reduction phase, just wide enough that the actual closing element remains closed and as a result no fuel injection process takes place.

Abstract: A detection system for identifying deterioration in a structure is provided that has acoustic sensors that receive acoustic emission waves. The acoustic emission wave detected by the acoustic sensor is identified as a hit. An analysis circuit is present that identifies an A state, a B state, and a C state. The B state has increased hit activity from the A state where a rate B is greater than a rate A by a factor of f1. The C state has increased hit activity from the B state where a rate C is greater than the rate A by a factor of f2. An alarm is activated when an amount of time that the C state is identified as being present reaches a value of TM, or alternatively when a threshold value based upon of the number of hits and time in the C state is reached.

Abstract: The present invention relates to a digital device and a method for measuring the axial load of a torque-shear-type high strength bolt. One embodiment of the digital device of the present invention includes: a main body portion which is connected to an electromotive wrench fastening a torque-shear-type high strength bolt; a measurement portion disposed at the main body portion to measure the axial load of the torque-shear-type high strength bolt using a quantity of the electricity from the electromotive wrench; a power supply portion disposed at the main body portion and including a power lead-in portion for receiving an external power supply and a power lead-out portion for supplying power to the electromotive wrench; and a display portion displaying the axial force value measured by the measurement portion.

Abstract: A torque detection device that detects a torque of a rotating body installed on an object unit, and comprises a distortion detector unit attached to the rotating body, an oscillation circuit disposed on the object unit, and a detection circuit disposed on the object unit and for converting a signal output from the distortion detector unit into a torque signal. The electro-magnetic coupler couples the distortion detector unit with the oscillation circuit electrically, and the electro-magnetic coupler couples the distortion detector unit with the detection circuit electrically. This structure can achieve downsizing of the torque detection device of high detecting accuracy.

Abstract: A device (1) and a method are provided for determining the oscillatory behavior of a brake lining (3) for a motor vehicle. The device (1) has a mounting device (2) for mounting a brake lining (3) and a securing device (6) for securing a brake disk model (7) assigned to the brake lining (3) so that the brake lining (3) can be brought to bear with the brake disk model (7) against a contact face (8). A pretensioning device (9) is coupled to the mounting device (2) and/or to the securing device (6) so that the brake lining (3) can be pressed against the brake disk model (7) with a pressure force (10, 10?) predetermined in terms of absolute value and direction. An excitation device (13, 13?) is provided for exciting oscillations of the brake disk model (7) and/or the brake lining (3).

Abstract: A computer implemented method, apparatus, and computer usable program code for testing a material. A signal is sent into the material using the transmitter. The signal has a frequency range that falls within a selected frequency range to form a transmitted signal. An actual response to the transmitted signal is received at a sensor. A simulated response of the material to the transmitted signal is generated using a functional model capable of modeling responses of the material to different frequency ranges falling within the selected frequency range. The simulated response is compared to the actual response to determine if a change has occurred in the material.

Abstract: A sensing apparatus utilizing film bulk acoustic resonators (FBARs). The film bulk acoustic resonator has a bulk acoustic wave velocity (Vb) and a corresponding resonant frequency (f). When the FBAR is subjected to a force such as acceleration, g-force or an air pressure, the bulk acoustic wave velocity changes to obtain a frequency downshift (?f) in response to deformation caused by the force. A magnitude of the force is then obtained by calculating the frequency downshift (?f).

Abstract: The force exerted by a reciprocating actuator is estimated as a weighted sum of three quantities: a reaction-mass acceleration, a baseplate acceleration, and a relative acceleration of the reaction-mass relative to the baseplate. In one embodiment, acceleration sensors measure the reaction-mass acceleration and the baseplate acceleration; and a displacement transducer measures a relative displacement of the reaction-mass relative to the baseplate. A double-differentiator generates the value of the relative acceleration from the second derivative of the relative displacement. In the sum, the relative acceleration is weighted by factor representative of the ratio of the difference between the masses of the reaction-mass and the baseplate to the sum of the masses of the reaction-mass and the baseplate.

Abstract: A pump monitoring system includes a monitoring device configured for attachment to a cable harness of a pump, a strain gauge configured to measure dynamic loading of at least one cable of the cable harness as the pump operates, a wireless transmitter configured to transmit the dynamic loading measurement, and an external device configured to receive the transmitted dynamic loading measurement.

Abstract: A sensor device for measuring frequency and amplitude of a varying force signal is provided. The sensor device comprises a sensing element defined by a plurality of even numbered planar segments symmetrically disposed about a central axis, a protective housing for housing, an interface element comprising a pick up member, a planar mechanical actuator, a transfer member adapted to receive varying signals from the pick up, amplify the signals picked up and transfer the amplified signals to the said mechanical actuator; and leads for transmitting said output signals outside the sensing device for processing.

Abstract: The present invention provides an axial bolt force measuring instrument for measuring an axial force of a bolt for a hub that couples a wheel and an axle of a vehicle, where the instrument is provided with a setting portion that sets a predetermined axial force of the bolt, a tapping portion that taps the bolt, a sound collecting portion that collects tap sound generated by tapping the bolt with the tapping portion, a frequency measuring portion that measures a frequency of the tap sound collected by the sound collecting portion, an axial force converting portion that converts the frequency of the tap sound measured by the frequency measuring portion into an axial force of the bolt, a comparing portion that compares the set axial force set in the setting portion with the converted axial force converted in the axial force converting portion from the frequency of the tap sound, and a display portion that displays a result of comparison in the comparing portion.

Abstract: A system and method is used for estimating the properties of a flexural beam. The beam is shaken transverse to its longitudinal axis. Seven frequency domain transfer functions of displacement are measured at spaced apart locations along the beam. The seven transfer functions are combined to yield closed form values of the flexural wavenumber in propagation coefficients at any test frequency.

Abstract: A wire tensioning apparatus and method tensions one or more wires by moving the tensioning function from a wire module to an apparatus external to the wire module. Within the wire module, the wire is placed between a movable member and a stationary member. Tension is placed on the wire and adjusted until the desired tension and/or vibrational frequency is met. Once the desired tension and/or vibrational frequency is met, the wire is clamped between the movable and stationary members within the wire module in order to maintain the achieved tension and/or vibrational frequency.

Abstract: A wire tensioning apparatus and method tensions one or more wires by moving the tensioning function from a wire module to an apparatus external to the wire module. Externally to the wire module, a wire is attached to a fixed end and a movable end. Tension is placed on the wire, and the tension in the wire or the vibrational frequency of the wire is detected and compared to a desired value. If the tension in, or the vibrational frequency of, the tensioned wire does not correspond to the desired value, the tension is further adjusted until the desired value is met. Once the desired tension or the vibrational frequency is met, the wire is secured in the wire module in order to maintain the achieved tension and/or vibrational frequency.

Abstract: A bicycle which comprises as force transmission equipment a chain for transmitting the muscular strength of a person pedaling the bicycle from the person to the bicycle for the purpose of moving the bicycle, characterized in that the chain has a vibration transducer which is arranged to vibrate at a resonance frequency proportional to the force transmitted by the chain, and the bicycle comprises a reading device separate from the chain for reading the resonance frequency of the vibration transducer, to which reading device calculation means are connected for calculating the force affecting the chain on the basis of the resonance frequency.

Abstract: A preload measuring apparatus to measure the preload of a rolling bearing that includes a bearing support, a pressurization device, an excitation device, a vibration sensor, and a control section. The bearing support supports a rolling bearing by supporting both ends of a shaft inserted into an inner ring of the rolling bearing. The pressurization device loads a predetermined weight in the axial direction onto the rolling bearing. The excitation device applies vibration onto the rolling bearing by the drive of the piezoelectric elements. The vibration sensor detects the vibration generated on the rolling bearing by the vibration application of the excitation device. The control section operates the excitation device in the situation that the pressurization device presses the rolling bearing, and obtains the resonance frequency by the output signal from the vibration sensor and calculates the preload of the rolling bearing according to the obtained resonance frequency before the predetermined weight as loaded.

Abstract: A sensor for an ultrasonic bonding apparatus comprises a piezoelectric material located between the ultrasonic transducer and an ultrasonic concentrator of the bonding apparatus. The sensor has at least two outputs for measuring different bonding parameters, the outputs being chosen to optimize the signal response for the bonding parameters in question.

Abstract: A method and an arrangement for sensing the clearance between an object and an object-adjacent surface, which is particularly for use in difficult ambient conditions, such as in dirty, corrosive environments and under varying temperature and pressure conditions, e.g. to measure and hold constant the clearance between the sector plates (3, 4) of a regenerative rotary air preheater and the end surfaces of the rotor (2, 8). The sensing device (7) includes a compressed-air operated pipe (9) which is mounted on the object (3, 4) and which includes a sound-emitting opening (14) located adjacent the surface (8), wherein changes in the distance (S) between the object (3, 4) and the surface (8) are represented by changes that occur in the resonant frequency of the pipe (9).

Abstract: A component machine testing technique is provided that performs diagnostic analysis on a vibration signal of the component machine that has been separated from power and load machine background noise in a first neural network. The diagnostic analysis, with operator direction through an interactive interface, uses a second neural network in performing a series of diagnostic operations followed by archival of any experience acquired in the testing operation being performed.In the diagnostic analysis, both time based and frequency based vibration signal information from the component machine under test are used together through a simultaneous multiple display interactive interface under operator direction.

Abstract: An apparatus and method for the non-contact measurement of tensile loading (or tension) in ferromagnetic materials, particularly wire ropes, cables, and strands. The magnetostrictive effect is used to measure wave propagation properties within such materials to determine load forces imposed on the tested material based upon a signature obtained for like materials under like conditions. The apparatus and method contemplate an active measurement application, wherein a transmitting sensor generates an mechanical pulse within a material through the magnetostrictive effect, and a receiving sensor detects reflected mechanical waves within the material by the inverse magnetostrictive effect. Unlike other sensing methods, utilizing the magnetostrictive effect in this way has the advantage of generating and detecting mechanical waves in the tested material without direct physical or acoustical contact.

Abstract: A method of determining the tension in a guy wire or other flexible member. The first 15 natural frequencies for the design tension and tensions at 1 percent increments above and below the design tension are calculated. The actual first 15 natural frequencies are then determined, and the tension in the wire is the one whose calculated frequencies are most similar to the actual frequencies. The method is sensitive enough to use the wind to excite the wire or it can be manually struck to produce vibrations.

Abstract: A method is provided for determining the axial modulus of an elongate matal sample of mass density .sup..rho. and length L. The first end of the sample is driven longitudinally at a frequency of excitation .sup..omega.. The second end of the sample opposite the first end may or may not be under tension. At the frequency of excitation .sup..omega., the longitudinal displacement and longitudinal force at the first and second ends of the sample are determined. The axial modulus is calculated for any frequency as a function of mass density .sup..rho., length L, frequency of excitation .sup..omega., and longitudinal displacement and longitudinal force at the first and second ends.

Abstract: In a stress measuring, system sensor driving power and a signal sensed by a sensor are transmitted and received in the form of a light pulse signal to thereby improve a noise resistant property as well as a measuring accuracy and reliability. The stress measuring system includes a sensor head disposed at a sensing location and a measuring device disposed at a location remote from the sensing location. The sensor head includes a sensor having a sensing section for sensing a change in stress as a change in the natural frequency of an oscillation string, an output section for outputting a light pulse sensing signal corresponding to the natural frequency sensed by the sensing section and a driving section for causing oscillation at the natural frequency of the oscillation system of the sensing section in response to a driving light pulse signal.

Abstract: A force sensor is provided which incorporates a piezoceramic element between first and second members that are moveable relative to each. The piezoceramic element is disposed within a cavity that is formed in the first member. The cavity extends between an opening and a wall within the first member. A second member is disposed within the cavity and slideably associated therewith. A spring is provided to permit the piezoceramic element to be preloaded without damaging it. First and second conductive elements are disposed on opposite sides of the piezoceramic element to facilitate electrical connection between the piezoceramic element and an external device.

Abstract: As an optical fiber (12) is being drawn, air (14) is directed at a portion of the fiber as a succession of air pulses, the pulses having a frequency near the natural frequency of the fiber portion. The frequency of the air pulses is then varied over a range of frequencies that includes the natural frequency of the fiber portion. When the air pulse frequency equals the natural frequency of the fiber portion, a resonance occurs which greatly amplifies the amplitude of the vibration of the fiber portion. The large deflection of the fiber that occurs at resonance is easy to detect, and the air pulse frequency which causes such maximum deflection is taken as being equal to the resonant frequency and therefore to the natural frequency of the fiber portion. Changes of the detected resonant frequency can be interpreted in a straightforward manner as changes in optical fiber tension which, in turn, are used to make compensatory changes of the temperature of the furnace (10).

Abstract: Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.

Abstract: As an optical fiber (12) is being drawn, air (14) is directed at a portion of the fiber as a succession of air pulses, the pulses having a frequency near the natural frequency of the fiber portion. The frequency of the air pulses is then varied over a range of frequencies that includes the natural frequency of the fiber portion. When the air pulse frequency equals the natural frequency of the fiber portion, a resonance occurs which greatly amplifies the amplitude of the vibration of the fiber portion. The large deflection of the fiber that occurs at resonance is easy to detect, and the air pulse frequency which causes such maximum deflection is taken as being equal to the resonant frequency and therefore to the natural frequency of the fiber portion. Changes of the detected resonant frequency can be interpreted in a straightforward manner as changes in optical fiber tension which, in turn, are used to make compensatory changes of the temperature of the furnace (10).

Abstract: A load measuring system comprising an acoustic transmitting transducer for injecting an acoustic signal into a load bearing portion of a sucker rod, and receiving transducer for detecting the signal after it passes through a known length of a sucker rod, and a time delay detector for determining the travel time and in turn, the velocity of the acoustic signal. The acoustic velocity is measured in an unloaded portion of the sucket rod to provide a zero load reference. Measurements are then taken in the loaded portion of the rod and used to indicate dynamic load on the sucker rod string.

Abstract: The presence, size and location of a crack in a shaft is determined by comparing actual measured natural frequencies of the shaft system with the results of an analytical model. From a multi-station analytical model of an uncracked shaft system, natural frequencies and associated mode shapes are derived. A suspected axial location of a crack is defined, and a natural frequency of interest is selected which has an associated mode shape exhibiting significant localized bending at the suspected axial location of the crack and at a site of response measurement. The analytical model is modified to include a representation of an asymmetric crack at the suspected crack location, and a predicted split and downward shift of a lateral natural frequency of interest and/or a predicted downward shift of a torsional natural frequency of interest as a function of crack depth is calculated from the modified model. The actual shaft system is subjected to an excitation force, and vibrational response measurements are taken.

Abstract: An ultrasonic transducer socket assembly for simultaneously tightening a bolt and measuring bolt load. A pole adaptor rigidly attached to a driving socket for engaging and driving a bolt has a stationary cylinder mounted therein. A second cylinder rotatably and slidably received in the stationary cylinder has an ultrasonic transducer pivotally mounted at one end that contacts the bolt to be tightened when the socket is engaged with the bolt. The rotating cylinder and transducer are rotated approximately 180 degrees during engagement of the socket and bolt to smear an even couplant layer between the bolt and transducer to assure consistent measurements of bolt load during tightening.

Abstract: The presence, size and location of a crack in a shaft is determined by comparing actual measured natural frequencies of the shaft with the results of an analytical model. From a multistation analytical model of an uncracked shaft, natural frequencies and associated mode shapes are derived. A suspected axial location of a crack is defined and a natural frequency of interest is selected which has an associated mode shape exhibiting maximum deflection at the supected axial location of the crack and at a site of excitation. The analytical model is modified to include a representation of an asymmetric crack, at the suspected crack location, and the predicted split and downward shift of the natural frequency of interest as a function of crack depth is calculated from the modified model. The actual shaft is subjected to a radial excitation force, and vibrational response measurements are taken with an accelerometer along multiple radial directions.

Abstract: A method for measuring vibrational stresses and velocities of waves propagated within formations surrounding a wellbore essentially consists in simultaneously measuring the vibrational stress and vibrational velocity produced by propagation of the vibration within the medium, then in establishing a ratio of magnitudes relating to the vibrational stress and velocity in respect of one and the same measuring point. The method and device provided by the invention also find applications in the separation of different types of secondary waves generated during propagation of a primary wave in a medium.

Abstract: A tightening wrench (5) carrying a measuring cell (8) freely mounted in the hollow part (4) of a wrench (5) and adapted to bear against an end of the pin (2) subjected to the pretension. A detector emitting and receiving ultrasounds (21) disposed inside the measuring cell (8) is made to bear against the end of the pin (2) by a spring (25) interposed between the cell (8) and the detector (21). The cell (8) itself bears against the end of the pin (2) through the action of a leaf spring (9) carried by the wrench (5).

Abstract: A method and apparatus for measuring tensile stress in a fastener already in place. This method capitalizes on the discovery that a longitudinal wave will travel roughly twice as fast as a transverse wave and the times-of-flight of the two waves are affected to different degrees by tensile stress. Longitudinal and transverse ultrasonic signals are applied to a first end of the fastener. The longitudinal and transverse signals are detected at this same first end of the fastener after they are reflected off of the second end of the fastener. The time-of-flight for each of the longitudinal and transverse waves is measured. The tensile stress, T, in the fastener is then determined by applying substantially the following equation: ##EQU1## where v.sub.10 and v.sub.20 =the velocities of the longitudinal and transverse signals, respectively, in a similar fastener not under stress;k=the length of the unstressed portion of the fastener;.lambda. and .mu.=Lame' constants for the fastener material; andD.sub.1 and D.sub.

Abstract: Tension in a moving web is measured by subjecting the web to an ultrasonic pulse train and measuring the time interval for the resultant transverse waves in the web to proceed a known distance past a point upstream (or downstream). The composite web plus wave velocity is calculated and the web travel time is added (or subtracted) to obtain wave velocity which is related to tension in accordance with the equation T=a.sup.2 w/g.sub.c, where T=web tension, a=wave velocity, w=mass per unit area and g.sub.c =lb mass ft/lb force sec.sup.2 conversion factor.

Abstract: A method and apparatus is provided for measuring the ratio between web tension and web substance by causing the web to vibrate at its resonance frequency, measuring the pressure variations or the signal causing the web vibration to produce a first signal, measuring a signal in phase and representative of the vibration of the web and to produce a second signal, comparing the phase difference of the first and second signals so that a deviation from a predetermined phase difference produces an output signal, and controlling the frequency of the signal or pressure variations causing the web to vibrate in response to the output signal so that the predetermined phase difference is maintained.

Abstract: Apparatus and method for determining the tensile load on a mine roof bolt, which is indicative of the support provided by the bolt. The device comprises a hammer for striking a roof bolt to produce a sound pulse, a microphone for picking up the sound pulse, and a sound comparator having a recorded sound or sounds whereby an operator can match the induced sound pulse with a recorded sound pulse to provide an indication of the tensile load on the roof bolt. The comparator may include a range of sounds, or may incorporate a variable speed function whereby the pitch of the recorded sound may be varied until the induced sound is matched. Comparison of the induced sound with the recorded sound provides an indication of the tensile load on the roof bolt.

Abstract: A tension in a paper or foil web is measured by subjecting an area of the web between points of support to transverse oscillations. The impedance of an oscillation generating means located adjacent the web changes with the oscillation and impedance is measured with the transverse oscillation at a frequency approaching the expected fundamental resonant frequency for the web tension under consideration. The damping effect of the transverse oscillations by the web is a function of the web tension.