Abstract: Acoustic volume indicators for determining liquid or gas volume within a container comprise a contactor to vibrate a container wall, a detector to receive vibration data from the container wall, a processor to convert vibration data to frequency information and compare the frequency information to characteristic container frequency vs. volume data to obtain the measured volume, and an indicator for displaying the measured volume. The processor may comprise a microprocessor disposed within a housing having lights that each represent a particular volume. The microprocessor is calibrated to provide an output signal to a light that indicates the container volume. The processor may comprise a computer and computer program that converts the data to frequency information, analyzes the frequency information to identify a peak frequency, compares the peak frequency to the characteristic frequency vs. volume data to determine the measured volume, and displays the measured volume on a video monitor.

Abstract: Apparatus and methods for measuring physical quantities making use of resonant structures, the resonant frequency of which changes with changes of the physical quantity. Techniques for detecting resonance are described. In one embodiment the apparatus comprises detecting circuit which has an arming circuit including a receiver which tracks the frequency of excitation signals and on the basis of the detected amplitude of the signals in that frequency range arms a comparator to compare signals indicative of the relative phase of the excitation signal and a signal reflected by the resonant structures which in turn allows resonance to be detected.

Abstract: A sound field measuring device according to the present invention uses a measurement signal which has at least one change point and whose frequency spectrum has a shape corresponding to a shape of a frequency spectrum of a background noise. This enables a sound field measurement, which is for measuring an impulse response or transfer function of a sound field space which is a linear time-invariant system to be measured, to be performed with a high S/N ratio over a wide frequency band.

Abstract: A flexural resonator includes a piezoelectric material. At least a portion of an electrode having a first surface and a second surface is embedded in the piezoelectric material such that the piezoelectric material is disposed over and in electronic association with the first and second surfaces of the electrode.

Abstract: A system may be used to indicate a need for replacement of a vibrating structure and includes a sensor, an indicator, and a processor. The sensor senses a frequency of vibration of the vibrating structure. The indicator is controlled to provide an indication of the need for replacement of the vibrating structure. The processor compares the frequency of vibration of the vibrating structure to data that relates the vibration frequency of the vibrating structure to fatigue damage of the vibrating structure, and controls the indicator based on the comparison.

Abstract: The present invention prevents instability of frequency measurement caused by spatial connection between quartz sensors adjacent to each other when a plurality of quartz sensors, including a quartz resonator which varies a national frequency due to adsorption of an object, are to be detected. A common measuring unit measures a variation in frequency of each oscillation circuit corresponding to each quartz sensor by switching and connection in turn, and the oscillation circuits, excepting an oscillation circuit connected to the measuring unit by switches, are connected to a load on the output side of the oscillation circuit channels connected to the measuring unit and the load value is such that the respective oscillating frequencies are forcibly separated from each other.

Abstract: A sensor is disclosed for analyzing information, such as interfacial interactions, found in various systems. A sensor is located proximate to an interface that is to be studied. The sensor is actuated in order to produce acoustical signals. The frequency of oscillation of the sensor is varied in order to enable the sensor to produce acoustical signals at different harmonics. The different acoustical signals are used to analyze the system at various distances from the surface of the sensor.

Abstract: An object of the present invention is to provide a highly sensitive Langevin type quartz sensor which is easy in assembling, is less likely to cause damage to a quartz resonator during the assembly work, and is easy to perform a measurement work. As a specific means to solve the problem, a recess is formed in a quartz holding member made of, for instance, rubber, and an airtight space is formed by holding the quartz resonator with the quartz holding member so as to cover the recess. In the meantime, a hole is provided in a circuit board and a projected portion which projects toward back side of the recess in the quartz holding member is fitted into this hole.

Abstract: The present invention makes use of resonant acoustic and/or acousto-EM energy applied to inorganic or biologic structures for the detection and/or identification, and for augmentation and/or disruption of function within the biologic structure. In particular, the invention provides a method of generating resonant acoustic and/or acousto-EM energy in biologic structures such as virus, bacteria, fungi, worms and tumors for the detection and disruption of these structures. Moreover, the invention provides a method of augmenting functions of biologic structures such as bone through the generation of resonant acoustic and/or acousto-EM energy in the structure. Systems are also provided for the generation and detection of resonant acoustic and/or resonant acousto-EM energy.

Abstract: A method and apparatus for determining the performance level, amount of wear, and remaining useful life of a new or worn object, preferably of metallic construction through harmonic fatigue evaluation. The object to be tested is struck with a resonant frequency generating device, causing the object to transmit its vibrational resonance to at least one signal receiving transducer. The transducer then relays the frequency back to a database wherein it is compared to known frequency responses of that specific object through a linear continuum from prior controlled testing, to determine the remaining performance level in comparison to a new object of the same construction.

Abstract: Method and system (i) to determine when a selected target molecule is present or absent in a fluid, (2) to estimate concentration of the target molecule in the fluid and (3) estimate possible presence of a second (different) target molecule in the fluid, by analyzing differences in resonant frequencies of vibration of a thin beam suspended in the fluid, after the fluid has moved across the beam.

Abstract: A method and system for microstructural evaluation and degradation evaluation of an object are provided. The method comprises insonifying at least one subvolume of the object with ultrasonic energy at a fundamental frequency and acquiring receive energy from the object at the fundamental frequency and at least one harmonic frequency thereof. A nonlinearity parameter is determined using the receive energy. The nonlinearity parameter is then used to determine a grain size for the subvolume of the object and a variation of the grain size within the object. The nonlinearity parameter is also used to determine fatigue damage or a residual stress.

Abstract: A resonance shear measuring method capable of simple and rapid measurement by obtaining a resonance shear curve through Fourier transformation of a damping curve of an oscillation on one side surface of a sample during measurement of shear response from the sample is provided.

Abstract: An apparatus for separating an analyte from a mixture or for detecting an analyte or for determining the affinity, or a property related to affinity, between binding partners includes: a) a surface having the analyte or one of the binding partners immobilized thereon, in use; b) a transducer for oscillating the surface; c) a controller connected to the transducer for varying the amplitude and/or frequency of the oscillation to cause a dissociation event; and, d) an analyzer connected to the transducer for detecting an oscillation of the transducer due to the dissociation event. The controller includes an oscillator connected in a resonant circuit with the transducer such that the transducer oscillates at two frequencies simultaneously, one of these causing the transducer to oscillate the surface and the other being supplied as an output to the analyzer.

Abstract: A system for detecting the lateral movement of thread in a textile manufacturing system is disclosed. The system includes an optical device configured to emit an optical signal. The optical device includes a resonant cavity. The system further includes a driver connected to the optical device. The driver configured to drive the optical signal. A mechanical guide is connected to the optical device. The mechanical guide is configured to receive a moving thread in a textile manufacturing process. The moving thread scatters the optical signal such that a portion of the optical signal is reflected back into the resonant cavity of the optical device; causing a change in the optical signal. An optical detector is optically coupled to the optical device. The optical detector is configured to detect the changed optical signal. Lateral movement detection circuitry is connected to the optical detector to detect lateral movements such as vibrations.

Abstract: A system and a method for calculating a synchronized time average for a measurement signal obtained from an object to be measured and containing periodical variations. In the method: from the periodical variations of the measurement signal a frequency is determined, said frequency corresponding within predetermined limits to a frequency estimated as the periodicity characteristic of the object to be measured; a signal component representing the determined frequency is separated from the measurement signal by filtering, and the filtered signal is used as a synchronizing signal, and the measurement signal is divided into sequences by means of the synchronizing signal, and the synchronized time average of the sequences is calculated. In an example of the method, the rotating frequency or the moving frequency of the object selected as the periodicity characteristic to the object.

Abstract: A flaw Z with a long probing length inside a probing target is allowed to be probed. The waves other than the probing target waves are removed or reduced, so that the individual difference in the sizing result due to the ability of the measuring personnel is eliminated to improve the precision of the probing. A transmission probe 31 and a receiving probe 32 for transmitting and receiving a wide band ultrasonic wave are included. Each time the positions of the probes 31 and 32 are moved, a received wave Gj(t) is obtained. From a spectrum Fj(f) corresponding to the received wave Gj(t), a narrowband spectrum FAj(f) is extracted. A component wave GAj(t) corresponding to the narrow band spectrum FAj(f) is obtained by inverse Fourier transformation. The component wave GAj(t) is provided for a comparative display using a predetermined sizing coefficient.

Abstract: An apparatus and method for determining the kinematic characteristics of a golf club head are disclosed. The apparatus includes at least one piezoelectric component selectively positioned within or upon a club head. The piezoelectric component is preferably positioned to the rear of the center of gravity, and near the midpoint of the face of the club head. During a golf club swing, the piezoelectric component determines the acceleration and deceleration of the golf club head. When the club head impacts an object such as a golf ball, the piezoelectric component is also operable to determine the velocity of the club head. It may also be desirable for the piezoelectric component to determine the magnitude of vibration during impact. In this manner, the piezoelectric component may function determine the efficiency of a golf club swing.

Abstract: A filter is set by a control apparatus automatically detecting a vibration frequency and determining a filter to be needed, in a simple method that does not require a special process. A servo control apparatus which drives a servo motor includes a vibration detection section which detects vibration of a control system, and a vibration frequency measuring and analyzing section. The vibration detection section detects the vibration when the vibration is generated during driving. The vibration frequency measuring and analyzing section measures a frequency of which vibration frequency component is large. Then, a frequency of a vibration suppression filter is set based on the vibration frequency.

Abstract: The invention disclosed that the multiple frequency ultrasound apparatus using unique transducer will contain many actuations module, a coupled circuit and a transducer. Each actuation module can separately output the signal of the different frequency, the coupled circuit connecting the actuation module for coupling with the signal of the different frequency. The transducer can receive the signal of the multiple frequencies, then for outputting the multiple ultrasound frequency by the way of transferring from the electrical energy to the mechanical energy.

Abstract: A panel inspection apparatus includes a resonant frequency extracting unit for extracting a plurality of resonant frequencies of a panel, a resonant frequency selecting unit for selecting a combination of resonant frequencies consisting of two resonant frequencies A and B with different vibration propagation paths among the extracted plurality of resonant frequencies, a non-defective range generating unit for generating a non-defective range on a coordinate system in which resonant frequencies A and B are taken on coordinate axes by statistically processing a set of the resonant frequencies A and B selected for each of a plurality of non-defective panels determined as non-defective in advance, and a panel quality determining unit for determining whether the quality of the panel to be inspected is good based on comparison between resonant frequencies A and B selected for the panel to be inspected and the non-defective range generated by the non-defective range generating unit.

Abstract: Methods and systems are provided for monitoring a solid-liquid interface, including providing a vessel configured to contain an at least partially melted material; detecting radiation reflected from a surface of a liquid portion of the at least partially melted material that is parallel with the liquid surface; measuring a disturbance on the surface; calculating at least one frequency associated with the disturbance; and determining a thickness of the liquid portion based on the at least one frequency, wherein the thickness is calculated based on L = f 2 ? w 2 g , where g is the gravitational constant, w is the horizontal width of the liquid, and f is the at least one frequency.

Abstract: An audiometer having an air-conduction receiver, a bone-conduction receiver, a masking receiver and an audiometer body is provided, in which the air-conduction receiver, the bone-conduction receiver, and the masking receiver are respectively provided with serial ROMs in which identification information and calibration information of each receiver are stored. The audiometer body comprises a misconnection detector for detecting misconnection of each receiver, a calibration period judging mechanism for judging a calibration transition period of each receiver, and a correction amount computer for computing a correction amount of sound pressure based on the information stored in the serial ROMs.

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: The invention relates to a method and device for determining the redox state of an anode (11), which is coated with a catalyst material or consisting thereof, associated with a high temperature fuel cell (10) or a reaction surface (16) of a reformer (13). According to the invention, at least one first resonator (3) of a piezoelectric sensor device (1) is arranged in the anode gas flow (5) of the high temperature fuel cell or in the gas flow of the reformer (13). The first resonator (3) is provided with a coating (4) which is oxidizable or reducible in the gas flow. The device also comprises a device (8) for measuring at least one modification of the resonance behaviour of the first resonator (3). The detected measuring value acts as an indicator of the redox state of the anode (11) of the high temperature fuel cell (10) or reaction surface (16) of the reformer (13).

Abstract: This present invention relates to a system for measuring resonant frequency and delay time of the quartz crystal microbalance. The system includes a transistor oscillating circuit, a switch circuit, a comparator circuit, and a control circuit. The transistor oscillating circuit comprises a quartz oscillator for generating an original oscillating signal. The switch circuit is coupled to the transistor oscillating circuit for outputting a start signal to generate the original oscillating signal. The comparator circuit is coupled to the transistor oscillating circuit for transforming the original oscillating signal to a square wave oscillating signal. The control circuit is coupled to the comparator circuit for receiving the square oscillating signal to estimate the resonant frequency and the delay time of the quartz crystal microbalance.

Abstract: The method decomposes the radio frequency signal into sub-bands by filtering, for example with a time-frequency transform. From the coefficients acquired through decomposition a matrix of spectral coefficients is obtained, from which local estimators are obtained, constituted in particular by the coefficients of the interpolating polynomials. The statistical distribution of the local estimators is evaluated in windows overlaid on the ultrasound frame. The conformation of the distribution histograms of the spectral coefficients provides a parameter which, combined with the local estimators, provides weighted local estimators, which contain spectral information useful in the identification of specific structures in the organ subjected to ultrasound analysis.

Abstract: A specific failure occurring during operation of a technical installation is detected by acquiring an acoustic and/or optical signal emitted by a device assigned to at least one component of the technical installation whereby the device is being activated mechanically.

Abstract: An acoustic wave sensor can be used to sense a liquid's properties such as temperature, corrosivity, density, and viscosity. Degraded measurements result when changes in one property are confused with changes in a different property. A rigid coating can minimize amount of measurement degradation due to viscosity changes in the liquid. A visco-elastic-interaction curve can be used to find the ideal thickness of the rigid coating, called the constant Q thickness. A visco-elastic-interaction curve relates the sensor Q to rigid coating thickness for a specific combination of sensor, liquid, and coating material.

Abstract: The present invention makes use of resonant acousto-EM energy (alone or in combination with resonant acoustic energy) applied to biologic structures for the disruption of at least one function of the biologic structure. In particular, the invention provides methods of generating acousto-EM energy in biologic structures such as virus, bacteria, fungi, worms and tumors for the disruption of these structures.

Abstract: A method for relieving residual stress in an object includes: (a) applying a vibration energy to the object over a frequency range; (b) monitoring vibration behavior of the object over the frequency range so as to identify a reference frequency, where the vibration amplitude of a fundamental wave component of the wave pattern is approximately one third of a maximum vibration amplitude of a resonate frequency of the object, and an optimum frequency, where the frequency and the vibration amplitude of the harmonic wave component of the wave pattern are respectively larger than those of the harmonic wave component of the wave pattern of the reference frequency; and (c) applying the vibration energy to the object at the identified optimum frequency for an extended period of time.

Abstract: A liquid measuring device and an automatic analyzer which employs a resonance phenomenon of sound waves to detect an amount of a liquid reserved in a vessel with an opening are provided. The liquid measuring device includes a sound source that emits sound waves toward the opening, a control device that controls a frequency of the sound waves emitted by the sound source, a wave receiver that measures a resonance generated as the sound waves emitted by the sound source causes an air column in the vessel to resonate, a detector that detects a resonance frequency of the resonance measured by the wave receiver, and a liquid-amount determination unit that determines, based on the detected resonance frequency, an amount of the liquid reserved in the vessel.

Abstract: The invention discloses a micro-sensor for sensing a chemical substance. The micro-sensor according to the invention includes a substrate, a micro-cantilever, an electrode structure, and a measuring device. The micro-cantilever is formed on the substrate and has a capturing surface for capturing chemical substances. The electrode structure is for supplying an electrical field. The electrical field is disposed so as to assist the capturing surface in capturing chemical substances. The measuring device, coupled to the micro-cantilever, is for measuring a variation on a mechanical property of the micro-cantilever induced by the captured chemical substance and interpreting the variation on the mechanical property of the micro-cantilever into information relative to the chemical substance.

Abstract: The invention relates to a method for measuring and/or regulating the oscillation amplitude of an ultrasound oscillator of an ultrasound device. In order to be able to measure or regulate the oscillation amplitude of the ultrasound oscillator in a simple manner, it is proposed that a sensor capturing the oscillation amplitude be associated with at least one component element of the ultrasound oscillator.

Abstract: A method for calculating material properties of a material includes determining a dilatational wavespeed and a shear wave speed. The dilatational wavespeed is determined by conducting vertical vibration tests of two specimens of the material, one specimen being twice as thick as the other. Transfer functions are obtained from these tests and used to calculate the dilatational wavespeed. The shear wavespeed is determined by conducting horizontal vibration tests of two specimens with one specimen being twice as thick as the other. The shear wavespeed can be calculated from transfer functions obtained from these tests and the dilatational wavespeed. Other material properties can be calculated from the dilatational and shear wavespeeds. Frequency dependence of the properties can be determined by conducting the tests at different frequencies.

Abstract: Kits and methods for building devices for analyzing or suppressing vibrations in equipment are provided. An electrical-mechanical transducer is configured to be placed in operative contact with the equipment. The transducer may be directly mounted to a base plate that is configured for being mounted to the equipment. A first device (e.g., a printed circuit board) carrying electronic componentry is configured for transmitting vibration drive signals to the electrical-mechanical transducer. A second device (e.g., a printed circuit board) carrying electronic componentry is configured for receiving vibration sensing signals from the electrical-mechanical transducer. The first and second devices can be interchangeably mounted within a housing that can be mounted to the base plate. The housing may comprise an aperture for receiving the electrical-mechanical transducer.

Abstract: The present invention pertains to apparatus and methods for measuring elastic modulus (Young's modulus) of non-solid materials, including honeycomb ceramic materials used in the filtration and/or treatment of exhaust gasses, through a range of temperatures.

Abstract: The present invention is a mechanical oscillator for detection and measurement of corrosive or foreign materials. The elements include a means for mechanical excitation, and a mechanical oscillator, wherein said mechanical oscillator has a resonant frequency, f, and a quality factor, Q. A fuse fixed to the oscillator to change oscillator amplitude to or from essentially zero to resonance amplitude. In a preferred embodiment, the mechanical oscillator has the shape of a tuning fork where one region is compatible with the service fluid and the other region is incompatible with the service fluid or other contaminant. The sensor alarms when a measured amount of the incompatible material has been removed or the physical strength of the material has been compromised.

Abstract: Devices usable as sensors, as transducers, or as both sensors and transducers include one or more nanotubes or nanowires. In some embodiments, the devices may each include a plurality of sensor/transducer devices carried by a common substrate. The sensor/transducer devices may be individually operable, and may exhibit a plurality of resonant frequencies to enhance the operable frequency bandwidth of the devices. Sensor/transducer devices include one or more elements configured to alter a resonant frequency of a nanotube. Such elements may be selectively and individually actuable. Methods for sensing mechanical displacements and vibrations include monitoring an electrical characteristic of a nanotube. Methods for generating mechanical displacements and vibrations include using an electrical signal to induce mechanical displacements or vibrations in one or more nanotubes.

Abstract: A new and improved metallurgic treatment and verification system and method. The system comprising several components in combination. First provided is an object to be tested. The object has a structural resonant frequency. Next provided is a vibration analyzer having a signal sending component and a signal receiver. Lastly provided is a cooling chamber having an enclosed space therein. The method comprises performing a first vibrational test on an object, and then cooling the object. The object is cooled for a specified amount of time and then allowed to return to ambient temperature at a rate determined by the physical characteristics of the object. A second vibrational test is performed and the data is compared with the first vibrational test to determine the effectiveness of the thermal treatment of the object.

Abstract: A non-contact detection technique of measuring both the frequency and the amplitude of periodic movement using a property of nonlinear phase modulation is provided. In one embodiment, the technique can utilize a 22-40 GHz radar sensor. Embodiments do not require calibration of signal amplitude for accurate measurement of movement amplitude. In addition, self-verification is possible. Furthermore, embodiments can provide measurements of frequency and amplitude using a very simple architecture. The method can be used to detect movements with amplitudes larger than 0.335 of the carrier wavelength for a fixed carrier frequency system and 0.214 of the minimum carrier wavelength for a frequency tunable system.

Abstract: A sensor network is attached to a structure and employed to detect and analyze load changes. The sensor network has transducers, capable of acting as both passive sensors and active actuators, integrated within it. In a passive mode, the transducers detect load changes upon the structure, such as impacts. Upon detection of a load change, the transducers are engaged in an active mode to actively scan the impact area to determine the location and size of any resulting damage region. In this manner, passive and active systems are integrated within a single, convenient layer that possesses the best features of both active systems and passive systems.

Abstract: A piezoelectric cantilever with a non-piezoelectric, or piezoelectric tip useful as mass and viscosity sensors. The change in the cantilever mass can be accurately quantified by monitoring a resonance frequency shift of the cantilever. For bio-detection, antibodies or other specific receptors of target antigens may be immobilized on the cantilever surface, preferably on the non-piezoelectric tip. For chemical detection, high surface-area selective absorbent materials are coated on the cantilever tip. Binding of the target antigens or analytes to the cantilever surface increases the cantilever mass. Detection of target antigens or analytes is achieved by monitoring the cantilever's resonance frequency and determining the resonance frequency shift that is due to the mass of the adsorbed target antigens on the cantilever surface. The use of a piezoelectric unimorph cantilever allows both electrical actuation and electrical sensing.

Abstract: The general field of the invention is that of resonating or vibrating devices. One of the tricky points with this type of device is that of correctly measuring the vibration frequency in a disturbed environment. The analysis system according to the invention is based on the use of the Hilbert transform of a function U representative of the position A of the vibrations of the device.

Abstract: A washing machine includes a rotary drum for accommodating therein laundry, the rotary drum having a horizontal or slanted rotational axis; a water tub supported in a vibratable manner in a washing machine main body, the rotary drum being installed in the water tub in a rotatable manner; a motor for driving the rotary drum; an input setting unit for setting an operation of the washing machine; a control unit for controlling the motor and the operation of the washing machine set by the input setting unit, the control unit including a microcomputer; and a displacement detection unit for detecting a displacement of the water tub. The displacement detection unit includes an excitation coil, at least two detection coils having an axis coaxially aligned with the excitation coil and a core which can move along the axis.

Abstract: An apparatus and method for testing flow noise of a motor vehicle are provided. The apparatus includes a blast nozzle device having at least one blast nozzle, and a transport device. The blast nozzle device is designed for the targeted impingement of the outer skin of the motor vehicle by air flow, and the transport device is designed such that the blast nozzle device and the motor vehicle may be moved relative to one another. A microphone array is positioned in the interior of the motor vehicle and measures the flow noise in the interior of the motor vehicle. The microphone array is preferably a spherical array. The flow noise in the interior of the motor vehicle generated by the air flow is measured by use of the microphone array.

Abstract: A method of determining damping performance of an article of manufacture includes moving an article of manufacture along a production line, directing a laser beam at a surface of the moving article and then measuring the velocity of a reflection of the beam simultaneously with measuring vibrational excitation in an environment of the production line. The method then includes calculating the damping performance of the moving article of manufacture based on the velocity and vibrational excitation measurements. The calculated damping performance may also be based on a predetermined correlation factor of damping performance of a reference article calculated based on the online system compared with damping performance of the reference article calculated in a controlled offline environment. A system for determining damping performance online is also provided.

Abstract: Embodiments of the present invention provide a system that performs vibration testing in a computer system. The system starts by generating a vibration at a predetermined frequency in a computer system. The system then determines if the computer system has a resonance at the predetermined frequency. If so, the system adjusts an operating parameter of at least one computer system component to prevent the computer system component from vibrating at or near a resonance frequency.

Abstract: There are provided a highly sensitive force/mass detection method and device using a phase-locked loop, in which a phase noise of the mechanical element can be reduced using the phase-locked loop, by synchronizing a vibration signal of a mechanical element to an oscillation signal from a local oscillator which has a low phase noise and a high purity property. In the highly sensitive force/mass detection device using the phase-locked loop, an oscillation circuit of a mechanical vibrator 1 including a phase adjuster 10, a binarization circuit 5 for detecting a phase of an oscillation signal of the oscillation circuit, a local oscillator 7 having a low phase noise and a high purity property, a phase comparator 6 for comparing the phase of the oscillation signal of the mechanical vibrator 1 with a phase of an oscillation signal from the local oscillator 7, and a loop filter 8 connected to the phase comparator 7, are provided.

Abstract: A method for predicting bearing failure, wherein the bearing includes an inner race, an outer race, and a plurality of rolling elements between the inner and outer race. The method includes coupling a sensor assembly to the outer race, the sensor assembly including at least one temperature sensor and at least one acoustic sensor, generating a bearing performance model based on an initial signal received from the sensor assembly, receiving a second signal from the sensor assembly, and comparing the second signal to the bearing performance model to predict a bearing failure.