Abstract: Systems and methods are provided for monitoring operating machinery to identify fault frequency sets for consumable components used in the machinery. Data associated with characteristic behavior of the machinery being monitored is acquired and analyzed, comparing known vendor information regarding fault frequencies for specified components to vibration frequencies observed in the machine in service. The systems and methods described herein enable an operator to identify and confirm critical information such as the location of and/or vendor identity for components exhibiting fault vibration behavior.

Abstract: Method for determining the contact angle (?) of a rolling element bearing (10) comprising an inner ring (12), an outer ring (14) and a plurality, P, of rolling elements (16) interposed between the inner ring (12) and the outer ring (14). The method comprises the step of determining the relative speed of P?1 or fewer of said plurality, P, of rolling elements (16) with respect to the inner ring (12) and/or the outer ring (14) and determining the contact angle (?) of said rolling element bearing (10) therefrom.

Abstract: A sensor unit for a bearing including at least one inner ring and at least one outer ring, wherein the sensor unit is configured to detect at least one state variable of the bearing. The sensor unit is embedded in a recess of one of the inner ring or the outer ring.

Abstract: A method for adjusting an axial preload in a bearing assembly that has two rolling-element bearings that are axially pressable against each other, each of the two rolling-element bearings including at least one bearing outer ring and at least one bearing inner ring and at least one row of rolling elements disposed between the at least one bearing outer ring and at least one bearing inner ring. The method includes a) driving the bearing assembly by rotating one of the bearing outer ring and the bearing inner ring while holding other bearing ring fixed and measuring the rotational speed of the circulation of the rolling elements about the bearing assembly axis or of a bearing cage about the stationary bearing ring, and b) changing the axial preload in the bearing assembly until a desired rotational speed has been obtained.

Abstract: An effective value operation unit calculates an effective value of a vibration waveform of a bearing, the vibration waveform being measured by using a vibration sensor. An envelope processing unit performs envelope processing on the vibration waveform measured by using the vibration sensor, thereby generating an envelope waveform of the vibration waveform. An effective value operation unit calculates an effective value of an AC component of the envelope waveform generated by the envelope processing unit. A diagnostic unit diagnoses an abnormality of the bearing based on the effective value of the vibration waveform calculated by the effective value operation unit and the effective value of the AC component of the envelope waveform calculated by the effective value operation unit.

Abstract: A method comprising the steps of determining normalized delta times of arrival corresponding to a plurality of blades based upon actual times of arrival corresponding to the plurality of blades, and determining static deflections of the plurality of blades by removing effects of one or more common factors from the normalized delta times of arrival corresponding to the plurality of blades.

Abstract: A system for monitoring an endless belt conveyor, comprising a sensor for sensing a vibration of an idler roller and generating a signal corresponding to the sensed vibration, at least one of the frequency and amplitude of the generated signal being indicative of a condition of the idler roller, the sensor being integral with the endless belt conveyor.

Abstract: An apparatus for mapping liner wear of a bearing around the circumference of the bearing which includes a rotary indexer that can hold the bearing, a shaft, a force applying mechanism, a rotating mechanism, a digital displacement indicator, and a recorder.

Abstract: A card reader device for reading a card having data stored on a magnetic stripe incorporated into the card is disclosed in which the card reader device comprises a read head for passing a magnetic stripe of a card by to read data stored on a magnetic stripe and for producing a signal indicative of data stored on a magnetic stripe, and an output plug adapted to be inserted into a headset jack associated with a host device for providing the signal indicative of data stored on a magnetic stripe to a host device.

Abstract: The present invention related to a method, and an apparatus arrangement, for determining a fatigue limit for rolling contact initiated fatigue of a rolling bearing. The method comprises running a rolling bearing while being exerted to a load which generates sub-surface transformations in a rolling element contact zone of the outer or inner ring. Furthermore a set of sub-surface transformations in the contact zone along a raceway portion of the rolling bearing is identified and measured and used for generation of a parameter data set, wherein a fatigue parameter value representative of a predicted fatigue limit for the rolling bearing is determined based on the generated data set of sub-surface transformations.

Abstract: An apparatus and a method for determining a damage state of a wheel bearing (12), in which a wheel (15) with a tire (9) arranged on a rim (8) in such a manner that the wheel can be rotated on an axle, in a motor vehicle, in particular during maintenance work on the motor vehicle. In order to avoid the wheel bearing (12) being accessed unnecessarily, a sensor unit (1) which communicates with an evaluation unit and is removably fastened radially outside a screw circle (11) of the rim (8) is provided for the purpose of determining the damage state.

Abstract: A method including acquiring a current vibration signal of an engine component mechanical vibration across a set of a measuring period P of changes in shaft speed N; capturing the signal during the period P; synchronizing the signal relative to the changes in the speed N; transforming the signal into a frequency signal for obtaining frequency spectrum lines arranged according to the speed N; calculating the mean amplitude of the spectrum lines to obtain a current vibration signature for the engine; calculating a deviation ratio between the signature and a healthy reference vibration signature; and comparing the deviation ratio to the defect indicators in a predefined database, listing the theoretical damage to the roller engine bearings so as to determine potential damage to the roller bearing.

Abstract: A method for predicting the residual life of a bearing comprising the step of: obtaining data concerning one or more of the factors that influence the residual life of the bearing using at least one sensor, obtaining identification data uniquely identifying the bearing, transmitting data to and/or from the at least one sensor using an industrial wireless protocol, and recording the data concerning one or more of the factors that influence the residual life of the bearing and the identification data as recorded data in a database.

Abstract: A vehicle service or inspection system including a load roller for applying a radial load to a vehicle wheel assembly consisting of a tire mounted to a rim, with at least one sensor for acquiring measurements of acoustical energy generated by the wheel assembly during loaded rotational movement. The vehicle service or inspection system is configured with a programmed processor to evaluate the acquired measurements to provide a measure of tire road noise, identification of tire defects, and/or identification of sources of noise, vibrations, or acoustical energy on the tire surface such as tire flat spots, cupping, bubbles, embedded foreign objects, or other defects. The processor is further configured with software instructions to utilize the acquired measurements to provide a consumer with a figure of merit associated with the acoustics of the tire undergoing testing.

Abstract: A method of analyzing blade displacements detected by circumferentially spaced stationary timing probes associated with an assembly of rotating blades mounted on a rotor, including (a) identifying a possible resonant vibration event in the assembly of rotating blades; (b) zeroing the blade displacements on the rotations identified with the resonant vibration event to remove invariant blade displacements; (c) fitting modelled blade displacements corresponding to possible blade vibrational deflections at various frequencies to the zeroed blade displacements; and (d) characterizing the resonant vibration event by identifying at each rotation the frequency having modelled blade displacements which correlate best with the zeroed blade displacements. Step (c) includes performing at each individual rotation the sub-step of fitting the modelled blade displacements at each frequency to the zeroed blade displacements for successive rotations which include that individual rotation.

Abstract: Methods and systems to achieve highly efficient rotational machine integrity determinations in which at least one sensor (106) senses indicia (105) such as time-varying rotational indicia from a rotational motive apparatus (103) and a processor (108) may provide many different functions including but not limited to operational function energy apportioning decisional processing, data compression, intelligent hierarchical data ranking, differential data processing, or the like perhaps to generate information (109) such as a rotational integrity abridgment transmissor to which an abridgment transmissor electromagnetic signal (112) may be created and perhaps even transmitted from a rotational motive apparatus to facilitate a machine integrity determination.

Abstract: The invention relates to a clamp (10) which is used mainly in a vibroacoustic diagnosis tool during an automobile maintenance or after-sales assistance opération, including two hinged arms (11, 12), each comprising a jaw (13, 14) at one end and a handle (15, 16) at the other end. A pad (20) is mounted on each jaw (13, 14) via a ball-and-socket joint (21), such that the pad (20) ensures effective contact between the clamp (10) and the part being tested, and séparâtes the body of the clamp from the listening part. The invention is useful in the field of motor vehicles. The invention is also useful in the vibroacoustic diagnosis of motor vehicles or motor vehicle subunits.

Abstract: A method provides detecting a contact state between at least one driver/operator of a vehicle and a control input device designed to control the vehicle, where a frequency spectrum is calculated from sensors detected movement signals based on which the contact state between the control input device and the driver/operator is determined.

Abstract: A system and method are provided for determining the health of an engine. The method includes a plurality of standard noise spectra collected from engines with known defects. A noise spectrum of the engine being monitored is sensed and compared to the plurality of standard noise spectra from the engines with known defects. From the comparison, a type and a degree of defect is identified based upon the comparison.

Abstract: The rotor of the turbine is monitored by sensors of the rotor vibrations arranged in at least one plane of measuring perpendicular to the axis of the rotor and by sensors of the absolute vibrations of the bearings. When using this method of processing, synchronically digitalized signals of the sensors of rotor vibrations, first the arithmetic mean of the individual harmonic bands in full spectrum in the frequency domain is calculated, by which means the information about the subharmonic components and their multiples in the full spectrum of these signals is transferred into the frequency band ?1X to 1X, at the same time is by the calculation of the median estimated the level of the signal noise, with which individual frequency bands of the full spectrum are encumbered, and which is subtracted from the amplitudes in the individual frequency bands of full spectrum of the signals of the sensors.

Abstract: In a method for determining and/or monitoring the state of a roller bearing wherein during the operation of the roller bearing a sensor signal in the form of a sound emission signal is detected in a frequency band in the ultrasonic range, according to an embodiment of the invention shock pulses in the sensor signal are determined. As a result, electrical bearing currents in the roller bearing can be detected and damage to the bearing can therefore be avoided early.

Abstract: A vibration sensor unit (66) is provided with a vibration sensor (72) and with an electronic signal processing circuit (82) which derives from the signals of the vibration sensor (72) information regarding a quantity of lost grain detected by the vibration sensor (72). The electronic signal processing circuit (82) also examines the signals of the vibration sensor (72) for vibrations that may be signs of potential damage to moving parts.

Abstract: The present invention relates to a mechanical assembly (10) provided with a sun gear (30) and a plurality of planet gears (50) co-operating with said sun gear (30). Each planet gear (50) includes a vibration sensor (61) forming part of structural anomaly monitoring means, said monitoring means being provided with a control member (63) that communicates with each vibration sensor (61) in order to receive a measurement signal coming from each vibration sensor (61) in order to enable anomaly monitoring to be performed.

Abstract: The present invention relates to an acoustic noise monitoring system for a wind turbine, comprising: a microphone for monitoring acoustic noise, the microphone adapted to be mounted to the exterior of a wind turbine nacelle; an input, the input adapted to receive operating conditions data from a wind turbine; a processor, the processor adapted to receive data from the microphone and the input; and storage memory, adapted to store the acoustic noise data and the operating conditions data. The processor is adapted to apply a transfer function to said acoustic noise data to correlate said data with a set of acoustic noise data measured at a remote location from the wind turbine. The system may comprise a controller adapted to generate a control signal, for outputting to a wind turbine controller, for adjusting the operating parameters of the wind analyser turbine in dependence on said correlated data.

Abstract: Method and apparatus for determining an operating point of a work machine and/or asynchronous motor driving the same, the operating point being characterized by the power consumed by and/or output rate of the machine, in which one or more operating point-dependent measurement variables of the machine are detected by sensors, and the measured values are evaluated and/or stored during operation of the machine. The operating point is determined without using electric measurement variables of the motor by determining a frequency linearly proportional to the fundamental tone of the machine through signal analysis, especially frequency analysis of a measured mechanical variable selected from pressure, differential pressure, power, vibration, and solid-borne or air-borne sound.

Abstract: The invention refers to a device for attachment to a rotating part (1) of a railway vehicle incorporating an arrangement, which is adapted, during movement of the railway vehicle, to detect and evaluate parameters related to the railway vehicle service and/or to an incipient fault state of wheel bearings (2) in the railway vehicle, and which device (12) is arranged to emit signals representative for the detected and evaluated parameters.

Abstract: A lubrication dispensing apparatus for lubricating a device with moving parts includes a lubricant reservoir, a lubricant dispenser for dispensing lubricant from the lubricant reservoir, an ultrasonic detection module which detects the amplitude of ultrasonic energy emitted by said device when its parts are moving and produces an signal related thereto, and a control module which analyzes the amplitude of the signal from the ultrasonic detection module and, in response to a lubricate signal, causes the lubricant dispenser to automatically dispense lubricant onto the moving parts of the device until the signal from the ultrasonic detector indicates that the ultrasonic energy produced by the device has decreased to a particular level. The control module includes a programmed processor and a storage memory. The memory stores as a base value the value of the detected amplitude of ultrasonic energy when the device is operating properly.

Abstract: A method of establishing position dependent focal laws and dynamically accessing these focal laws during inspection is disclosed comprising the steps of partitioning a CAD model into distinct geometric regions prior to inspection, generating a dedicated set of focal laws for each of the geometric regions, and associating each position of the scanner with one of the geometric regions. A method of compressing an A-Scan using a windowing technique is also disclosed. Additionally, methods for computing and displaying volumetric slices in real-time are disclosed. Finally, a method of firing multiple probes at different firing frequencies is disclosed, as well as a multi-probe inspection system that enables parallel firing.

Abstract: An approach for detecting rotor anomalies is disclosed. An on-site monitoring unit monitors vibration measurements obtained from a rotor during a transient speed operation. In one aspect, the on-site monitoring unit classifies the vibration measurements into predetermined ranges of rotor speed during the transient speed operation, determines maximum vibration data for each of the predetermined ranges of rotor speed during the transient speed operation and compiles the maximum vibration data into a snapshot of the vibration measurements obtained during the transient speed operation. A remote monitoring unit detects a rotor anomaly from the snapshot of vibration measurements generated by the on-site monitoring unit.

Abstract: A method and an apparatus are disclosed for monitoring the state of a roller bearing. The apparatus includes a vibration sensor, configured to detect vibrations which occur during operation of the bearing, and to generate a first signal as a function of the detected vibrations. A diagnosis electronics system is configured to output an item of information about a state of the bearing on the basis of the first signal and at least one limit value stored in the diagnosis electronics system. A sound emission sensor is provided, configured to pick up noises, produced in the event of plastic deformation of the bearing at least in regions. A second signal is then transmitted to the diagnosis electronics system, taking into account the picked-up noises.

Abstract: Placement of structural health monitoring sensors within a coupled bearing assembly. An exemplary structural health monitoring system comprises first and second bearings configured for rotatable positioning along a structure, and a spacer positioned between the first and second bearings. The first and second bearings are placed against opposing sides of the spacer, and have a preload force engaging the respective first and second bearings against the opposing sides of the spacer. A plurality of sensors are coupled to the spacer so as to be positioned between the spacer and at least one of the first and second bearings, the sensors further coupled to at least one of the first and second bearings so as to be configured to monitor a structural health of the at least one of the first and second bearings.

Abstract: A portable apparatus for determining testing the condition of a machine or device using ultrasonic signals with an array of ultrasonic sensors for receiving an ultrasonic signal transmitted from the machine or device. The apparatus possesses a heterodyne circuit coupled to receive the output signals from the ultrasonic sensors and convert the output signals to a heterodyned audio signal to be analyzed via a digital spectrum analyzer integral to the portable apparatus. The digital spectrum analyzer performs real-time fast fourier transformations on the heterodyned audio signal. After analyzing the signals, the hand held device uses a variety of audiovisual cues to direct a user to portions of the machine in need of repair or monitoring.

Abstract: Embodiments of the present application can provide systems and methods for mode shape identification of turbine buckets. According to one embodiment, a system can be provided. The system can include a turbine bucket having numerous trigger patterns disposed at a distal end of the turbine bucket. A sensor is disposed adjacent to the distal end of the turbine bucket for detecting the trigger patterns. The trigger patterns are patterned to identify at least one mode shape of the turbine bucket.

Abstract: A method of matching sensors in a multi-probe blade vibration monitor for a turbine. The method includes providing at least two probes mounted in a casing of the turbine adjacent to a rotating blade structure of the turbine. Targets are provided on radially outer portions of the blade structure. Each of the probes includes a sensor generating signals corresponding to target passing events, and a set of synchronous harmonics of the rotational speed of the rotor are produced for each sensor. The position of the sensors is adjusted such that the sets of harmonics of the sensors are substantially matched, indicating that the positions of the sensors are matched.

Abstract: A machine has at least two wheels (at least one of them driven) arranged on a base body and connected with a revolving belt. A transmitter and a receiver are arranged on the base body. The transmitter transmits contactless to the belt a transmitted signal having an oscillation frequency, with the receiver from the belt a reflected signal in response to the transmitted signal. An evaluation device connected to the receiver checks if the reflected signal received by the receiver satisfies an acquisition condition indicating that a speed of the belt is in a predetermined speed range. The evaluation device determines, if the acquisition condition is satisfied, a frequency spectrum which is based of the oscillation frequency and the reflected signal in the predetermined speed range and indicative of a mechanical oscillation characteristic of the belt, and generates a control signal based on the evaluated frequency spectrum.

Abstract: The disclosed embodiments generally relate to non-destructive evaluation methods. In an embodiment, a method for non-destructive evaluation of a machine-riveted bearing includes positioning a first plurality of sensors in the region of interest, the first plurality of acoustic sensors being provided in a phased array, positioning a second plurality of sensors in the region of interest, the second plurality of sensors being provided in a phased array, inducing a vibration in the region of interest using the first plurality of sensors and receiving a resonance frequency spectra using the second plurality of sensors, and comparing the received resonance frequency spectra against a reference spectra to determine the presence of an anomaly in the region of interest.

Abstract: An inspection vehicle structured to inspect a portion of the turbine disk, preferably the blade attachment hubs, while the turbine disk is disposed within a turbine housing assembly is provided. A turbine disk is generally planar but includes a inner hub and an outer blade attachment hub. The inner hub is coupled to a shaft and the blade attachment hub provides a surface to which removable blades are attached. The area between the inner hub and outer blade attachment hub is substantially planar. The inner and blade attachment hubs are the “inspection areas” that the inspection vehicle is structured to inspect. The inspection vehicle travels over, and is magnetically coupled to the planar surface between the two hubs.

Abstract: In a method of inspecting a wheel hub unit configured by attaching a rolling bearing. Which has an inner ring and an outer ring, to a hub wheel, an acoustic inspection dement is arranged so as to be in contact with an outer peripheral face of the outer ring, and the wheel hub unit (components except the outer ring) is rotated to measure an acoustic value of the outer ring and hence conduct inspection. When the wheel hub unit (components except the outer ring) is rotated, a preloading load that is equal to or higher than a load at which an axial internal clearance of the rolling bearing is a negative clearance is applied to the rolling bearing, and the axial internal clearance of the rolling bearing A is changed from a positive clearance before application of the load to a negative clearance after application of the load.

Abstract: A front wheel drive bearing defect amplifier is attached to a wheel gauge mount. The amplifier includes a magnet which is positioned approximately at the center of the wheel assembly. A spacing block, including a hollow aluminum handle, is pivotally mounted onto the magnet. A shaft or pin interconnects the magnet and the aluminum block and allows rotation of the magnet, in fixed engagement with the wheel assembly. The shaft is loosely fitted through a hole in the block. Opposite ends of the shaft are rigidly secured with the magnet so as to rotate with the magnet. An aluminum tube defines a handle having one end of the handle force fitted into an opening in the aluminum block. An opposite end of the aluminum tube or handle is to be held by the hand of the operator.

Abstract: The present invention provides a high accuracy, inexpensive diagnosis method and system diagnosing an abnormality of a 10 rpm or less very low speed roller bearing using an acoustic signal, that is, detects an acoustic signal emitted from a roller bearing of a 10 rpm or less ultralow speed rotating machine using a sensor having a sound pickup performance of 10 kHz or less, uses frequency analysis to find the spectrum distribution, processes this to obtain the frequency analysis waveform, compares the spectral average value or effective value of a frequency of the natural frequency of the bearing or more of this with a reference value, and judges that the bearing is abnormal when this spectral average value or effective value exceeds the reference value.

Abstract: The patron restraint system for amusement rides includes a locking receiver with a locking assembly for engaging a restraining strap. The engagement of the restraining strap in the locking receiver can be verified by a ride operator by visual or physical inspection, or by a sensor system indicating the locked or unlocked state of the locking receiver. A latching ratchet mechanism may be provided in the receiver to restrict movement of the restraining strap until it is released by the ride operator. The sensor system includes an acoustic sensor that detects alignment of an aperture with a piezoelectric acoustic emitter and an acoustic detector.

Abstract: A method for identifying possible damage in a toothed transmission stage having at least one pair of engagement toothed wheels includes measuring with a vibration transducer an oscillation signal corresponding to oscillations produced by a rolling and impact motion when teeth of a pair of the toothed wheels mesh under load during operation of the transmission stage, comparing the oscillation signal with a calibration oscillation signal, determining a torque acting on the transmission stage from a difference between the oscillation signal and the calibration oscillation signal, and evaluating the measured oscillation signal commensurate with the determined torque to identify the possible damage to the transmission stage.

Abstract: The damage length measurement system has an object being measured that comprises a plurality of members is vibrated by an oscillator, and the vibration that propagates through the object being measured is detected by three sensors. A measurement apparatus analyzes that vibration wave, and measures the arrival time of the maximum peak. Using the fact that the time for a wave to propagate between two vibration detection sensors separated by a set interval is fixed, the measurement apparatus determines whether the difference in arrival time between two sensors is within a set reference range that includes the vibration propagation time between two vibration sensors. When the measurement apparatus determines that the difference is not within the set reference range, uses the fact that that wave is delayed compared to the wave that was to be detected.

Abstract: A phased array ultrasonic testing system for examining discontinuities in turbine or generator rotor bores formed within turbine or generator rotors of a turbine or generator rotor assembly. The system includes a phased array ultrasonic transducer structured to be coupled to a surface of the rotor bore at a first location in order to emit an ultrasonic beam toward a second location of the rotor bore which is to be examined. The system further includes a control system with a computer and a controller for programming, emitting, and steering the ultrasonic beam via at least one, two-dimensional phased array transducer, thereby precisely and accurately inspecting the area of interest. Computer control of the beam permits the number of inspection locations and the number of different transducer wedges to be reduced providing for an efficient, timely inspection.

Abstract: An arrangement and method for determining and monitoring the state of a rolling bearing, wherein a first sensor signal is captured in the form of a sound emission signal in a first frequency band in the ultrasonic range during operation of the rolling bearing, a second sensor signal is captured in a second frequency band of lower frequency in the ultrasonic range, a first characteristic value for recently occurred damage is determined from the shape of the first sensor signal, a second characteristic value for recently occurred damage is determined from the shape of the second sensor signal, and the state of the rolling bearing is determined by comparing the first characteristic value to a reference value dependent on the speed of the rolling bearing and dependent on the second characteristic value to at least one second reference value dependent on the speed of the rolling bearing.

Abstract: A spherical bearing provides a passive apparatus that enables a contact sensor that needs to self-align to the surface of a test object. In some embodiments, the contact sensor is a transducer. This self-alignment apparatus may be used in a measurement system for aligning the face of a contact transducer to the surface of a material to be measured. The spherical bearing may be dry or may be lubricated with a liquid or with pressurized air to minimize the bearing friction and enable the transducer to self-align. The upper portion of the spherical bearing is preferably attached to a spring-loaded piston. The transducer is preferably attached to the lower portion of the spherical bearing. The spring-loaded piston holds the spherical bearing portions together and centers the floating lower bearing portion after each measurement operation. A cowling preferably retains the lower bearing portion between measurements.

Abstract: The invention relates to a wind turbine comprising at least one gearbox. The gearbox comprises one or more sensors for measuring condition values of the wind turbine, and is characterized in that the one or more sensors are mounted on one or more rotating parts of the gearbox. The invention further relates to an epicyclic gearbox comprising a gearbox housing, one or more gearbox parts rotating in relation to the housing, and one or more sensors for measuring condition values of the gearbox. The epicyclic gearbox is characterized in that, the one or more sensors are mounted on one or more of the rotating parts of the gearbox.

Abstract: An apparatus and a method for determining a damage state of a wheel bearing (12), in which a wheel (15) with a tire (9) arranged on a rim (8) in such a manner that the wheel can be rotated on an axle, in a motor vehicle, in particular during maintenance work on the motor vehicle. In order to avoid the wheel bearing (12) being accessed unnecessarily, a sensor unit (1) which communicates with an evaluation unit and is removably fastened radially outside a screw circle (11) of the rim (8) is provided for the purpose of determining the damage state.

Abstract: A method for determining a physical property of an object or fluid in a dynamic multi-path clutter environment comprises transmitting an RF interrogation signal to a wireless sensor physically coupled to the object or fluid (gas or liquid) in the dynamic multi-path clutter environment, wherein the wireless sensor is operable to receive the RF interrogation signal, produce a reference signal and a measurement signal, and retransmit the reference signal and the measurement signal in the dynamic multi-path clutter environment. The reference signal and measurement signal are delayed by the wireless sensor by an amount of time that may be a function of the unknown physical property. The method also comprises receiving the retransmitted reference signal and the retransmitted measurement signal and comparing them in the time domain in order to determine the unknown physical property of the object or fluid.

Abstract: A method including acquiring a current vibration signal of an engine component mechanical vibration across a set of a measuring period P of changes in shaft speed N; capturing the signal during the period P; synchronizing the signal relative to the changes in the speed N; transforming the signal into a frequency signal for obtaining frequency spectrum lines arranged according to the speed N; calculating the mean amplitude of the spectrum lines to obtain a current vibration signature for the engine; calculating a deviation ratio between the signature and a healthy reference vibration signature; and comparing the deviation ratio to the defect indicators in a predefined database, listing the theoretical damage to the roller engine bearings so as to determine potential damage to the roller bearing.