Abstract: A monitoring assembly for a filter includes an acoustic apparatus. The acoustic apparatus includes a first receiver, a second receiver, a resonator, and a transmitter. The transmitter is configured to emit sound waves receivable by at least one of the first receiver, the second receiver, and the resonator. The monitoring assembly also includes an electronic control module configured to receive signals from at least one of the first and second receivers.

Abstract: A cantilever array having a simple structure and being able to reliably detect a surface of a sample, a method for fabricating the same, a scanning probe microscope, a sliding apparatus of a guiding and rotating mechanism, a sensor, a homodyne laser interferometer, a laser Doppler interferometer having an optically exciting function for exciting a sample, each using the same, and a method for exciting cantilevers. The cantilever array includes a large number of compliant cantilevers sliding on a surface of a sample.

Abstract: A load-bearing structural member has a continuous structural material with piezoelectric material particles mixed in throughout. The structural material may be any of a variety of suitable materials, such as polymer materials, composite materials, ceramic materials, or concrete. The piezoelectric material particles may be used for evaluating the soundness of the structural member, such as in quality control or structural health monitoring processes. The structural member may include one or more conductive pickups used for receiving signals from the structural member. The signals may be induced by introducing ultrasonic signals or vibrational resonance signals into the structural member. The response from such induced signals may be used for quality control purposes or structural health monitoring.

Abstract: A monitoring assembly for a filter may include a transmitter, arranged on a first side of the filter, configured to emit sound waves. The monitoring assembly may also include a first receiver, arranged on the first side of the filter, configured to receive the sound waves. The monitoring assembly may further include a second receiver, arranged on a second side of the filter, configured to receive the sound waves.

Abstract: An acoustic wave sensor array device is provided for the detection, identification, and quantification of chemicals and biological elements dispersed in fluids. The sensor array device is capable of the simultaneous characterization of a fluid for multiple analytes of interest. A substrate has a plurality of channels formed therein and a sensor material layer applied in a bottom of the channels. The sensor material layer has a shear acoustic wave speed lower than a shear acoustic wave speed in said substrate. The channels may have the same material in each channel or different materials in at least two of the channels. A surface acoustic wave transducer and at least one surface acoustic wave reflector, or at least two transducers is formed on a surface of the substrate opposite the channels at a portion of the substrate that is thinned by the channels, so that the acoustic tracks of the surface acoustic wave device extend along the channels.

Abstract: Flowmeters are described in which a sensor signal received from a sensor that is attached to vibratable flowtube, so as to determine properties of a fluid within the flowtube, contains a drive signal component and a coriolis mode component. The flowmeters are operable to determine drive parameters of the drive signal component, as well as coriolis parameters of the coriolis mode component. By analyzing the sensor signal based on the drive signal parameters, and not on the coriolis signal parameters, the flowmeters are able to provide stable and accurate determinations of the properties of the fluid.

Abstract: Test sound wave is outputted from a speaker. A movable part of a three-axis acceleration sensor, which is a micro structure of a chip to be tested TP, moves due to the arrival of the test sound wave which is compression wave outputted from the speaker, that is, due to air vibrations. A change in the resistance value that changes in accordance with this movement is measured on the basis of an output voltage that is provided via a probe needles. A control part determines the property of the three-axis acceleration sensor on the basis of the measured property values, that is, measured data.

Abstract: A system including a processor, a high-energy density system linked to the processor, and a communicator linked to the processor. The communicator comprehensively integrates a plurality of hardware and software functions associated with operating the high-energy density system into a single, convenient interface. In one exemplary embodiment, the communicator comprises a wireless communicator. In operation, the communicator generates a command signal whereby the command signal is received by the processor. Accordingly, the processor controls the high-energy density system based on the command signal. In one aspect, the communicator interfaces with a security system for selectively limiting user access through a restricted system. In another aspect, the communicator is used for object information storage and retrieval associated with operating a high-energy density system, such as an ultrasonic laser system. In another aspect, the communicator is used to control a robotic device.

Abstract: A marker detection apparatus detects a marker attached to a target sample from samples flowing in a sample flow, wherein the sample flow carries a low ionization-tendency metal fine particle selected from a group of Au to Ag and the target sample labeled by the marker that is a particle of a unique vibration frequency, the marker detection apparatus including: an electromagnetic wave applying section that applies an electromagnetic wave to a path of the sample flow under a condition that the radius of the metal fine particle is smaller than the wavelength of the electromagnetic wave; and a detection section that detects vibration of the particle attached to the target sample, the vibration arising from a quasi-electrostatic field generated on the surface of the metal fine particle when the electromagnetic wave is applied to the metal fine particle around the target sample in the sample flow.

Abstract: Deterioration of reinforced concrete pipes is checked and the deterioration progress level is classified. Based on the inspection result, a portion to be inspected in detail in an inspection area is selected. With respect to the selected portion to be inspected in detail, the pipe thickness and the diameter of reinforcing bars are measured and the location of reinforcing bars in the portion to be inspected in detail are checked. Using the data of the thickness of a pipe, the diameter of the reinforcing bar and disposition of the reinforcing bars, structural analysis is carried out and the strength of the reinforced concrete pipe is calculated. The calculation result is used as information for evaluating the deterioration state of the reinforced concrete pipe.

Abstract: A system includes an ultrasonic transducer positioned to be in contact with the outer surface of a paper roll. The system further includes a transmitter circuit and a receiver circuit in communication with the ultrasonic transducer. The transmitter circuit provides a transmit signal to the ultrasonic transducer for generating an ultrasonic signal, which is transmitted into the paper roll. The receiver circuit provides a received signal indicative of an ultrasonic return echo from the paper roll. The ultrasonic return echo resulting from the ultrasonic signal interacting with the paper roll. The system also includes a processor circuit for determining an amount (length or diameter of roll) of paper remaining on the paper roll in response to the transmit signal and the receive signal. The processor provides an output signal when the amount of paper remaining falls below a threshold. A method of sensing paper on a paper roll is also presented.

Abstract: Using an ultrasonic field, properties of a solid liquid suspension such as through-transmission attenuation, backscattering, and diffuse field are measured. These properties are converted to quantities indicating the strength of different loss mechanisms (such as absorption, single scattering and multiple scattering) among particles in the suspension. Such separation of the loss mechanisms can allow for direct comparison of the attenuating effects of the mechanisms. These comparisons can also indicate a model most likely to accurately characterize the suspension and can aid in determination of properties such as particle size, concentration, and density of the suspension.

Abstract: A transducer for dynamic testing of specimen is disclosed. The transducer comprises at least two equally-spaced actuators, and a supporting block for supporting the at least two equally-spaced actuators and for mounting the transducer to the specimen. Each of the at least two equally-spaced actuators is an electrically powerable for providing to the specimen: a force or a moment. The actuators may be bimorphs and the transducer may be able to operate as an actuator, a sensor, and simultaneously as an actuator and a sensor. This may be for the transducer being able to operate as a sensor, for measurement of at least one selected from the group consisting of: an excitation force exerted on the specimen, an excitation moment exerts on the specimen, a resultant translational velocity of the specimen at an excitation point, and a rotational velocity of the specimen at the excitation point.

Abstract: The present invention, in one set of embodiments, provides methods and systems for integrating conducting diamond electrodes into a high power acoustic resonator. More specifically, but not by way of limitation, in certain embodiments of the present invention, diamond electrodes may be integrated into a high power acoustic resonator to provide a robust sensing device that may provide for acoustic cleaning of the electrodes and increasing the rate of mass transport to the diamond electrodes. The diamond electrodes may be used as working, reference or counter electrodes or a combination of two or more of such electrodes. In certain aspects, the high power acoustic resonator may include an acoustic horn for focusing acoustic energy and the diamond electrodes may be coupled with the acoustic horn.

Abstract: There is provided a method for measuring in-situ the acoustic attenuation obtained by a hearing protection device worn by a user, comprising: positioning the hearing protection device comprising a microphone oriented towards the user's ear canal at the user's ear; positioning a cup-like measuring device comprising a loudspeaker oriented towards to user's ear and a microphone oriented towards to user's ear at the user's ear in such a manner that a closed space surrounding the hearing protection device is created by the measuring device; providing a test signal via the loudspeaker, capturing audio signals representative of the level of the test signal in the closed space by the microphone of the measuring device and capturing audio signals representative of the level of the test signal in the user's ear canal by the microphone of the hearing protection device; processing the audio signals captured by the microphone of the measuring device and the audio signals captured by the microphone of the hearing protectio

Abstract: A method of inspecting canopy structures is provided to determine the structural integrity of the roof support system. The method includes steps designed to uncover hidden deficiencies in the roof support system through nondestructive testing and discovery. Timely use of the method of inspection not only minimizes the risk of canopy collapse but also produces information needed for making repair or replacement of the roof support system.

Abstract: A non-explosive shockwave generator system for hydrodynamic pressure processing of food products, the generator including a volume of fluid about a food product, a piston in a cylinder arranged to strike the volume, and a subsystem for driving the piston to impact the volume of fluid to create a shockwave which travels through the food product.

Abstract: A method and device for automatically assessing loss of hearing sensitivity and compression (recruitment) with user defined frequency resolution by means of extrapolated DPOAE I/O functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested using a device having a display screen attached to a handheld device generating and collecting otoacoustic emission signals and brain stem response signals into a programmed with a clinical audiogram with fitting parameters for hearing aids calculated on the basis of assessed hearing threshold and compression and identifying the type of hearing required for the individual.

Abstract: There are provided a cantilever array having a simple structure and being able to reliably detect a surface of a sample, a method for fabricating the same, a scanning probe microscope, a sliding apparatus of a guiding and rotating mechanism, a sensor, a homodyne laser interferometer, a laser Doppler interferometer having an optically exciting function for exciting a sample, each using the same, and a method for exciting cantilevers. The cantilever array includes a large number of compliant cantilevers (3) sliding on a surface (2) of a sample (1).

Abstract: An electronic bait station utilising the disruption of an electromagnetic field to detect the movement of insects or small animals within the station. The bait station consists of a housing, with at least one cavity having an electromagnetic radiation element generating an electromagnetic field in the cavity, and an electromagnetic receiving element detecting the electromagnetic field. Movement of an insect or small animal in the cavity causes a change in the electromagnetic field, which is detected. The preferred bait station comprises an outer cavity and a coaxial inner cavity, each with an electromagnetic field. This arrangement allows the direction of movement of insects and small animals to be determined and minimises the occurrence of spurious signals.

Abstract: A method of monitoring engine order forcing frequency comprises the steps of: selecting at least one engine order for an engine, the engine order being related in a known manner to one or more engine vibration responses generated by the forcing of the engine order; receiving measurement data which provide a measure of the change in the frequency of the or each vibration response as the engine speed varies, and calculating therefrom the change in the engine order forcing frequency; and determining, on the basis of the calculated change in the engine order forcing frequency, a corresponding change in at least one second engine order forcing frequency for the engine as the engine speed varies.

Abstract: A method of reducing sound-induced vibrations in pellicles used in lithographic production of microelectronic features comprises providing a pellicle for protecting a photomask, monitoring background sound in the vicinity, or vibration, of the pellicle, providing opposing sound waves to the background sound, and causing the opposing sound waves to strike the pellicle to substantially cancel vibrations due to the background sound or vibration. When the background sound strikes the pellicle on one surface of the pellicle, the opposing sound waves may strike the pellicle on the opposing surface of the pellicle, and may be provided with substantially the same frequency and amplitude in the same phase to the background sound. Alternatively, opposing sound waves may strike the pellicle on the same surface of the pellicle as the background sound waves, may be provided with substantially the same frequency and amplitude in opposing phase to the background sound.

Abstract: A device for examining materials, in particular trees, other kinds of wood, and concrete, with a pulse generator (1) for generating a pulse that can be introduced into the material (2), with at least one sensor (3) adapted for being associated to the material (2) for detecting the pulse, and with an electronic evaluation device (4) for discriminating the pulse from interference pulses, is designed and constructed with respect to a universal application to even large test pieces of the material (2) being examined in such a manner that an electronic evaluation device (4) is associated to each sensor (3).

Abstract: A nondestructive inspection method for composite structures, including thick core structures, is disclosed that imparts a vibration force into the structure and analyzes the response over a range of frequencies to find possible damaged areas. The composite structure is struck to induce vibration at a series of test points and the response of the composite structure as a function of acceleration at each test point is measured. The structural anomalies in the composite structure occur at structural stiffness irregularities near anomalies and are detected with a Gapped Smoothing Method operating on the data and plotting a structural irregularity index as a function of frequency and position.

Abstract: A method and apparatus for detecting seals on a film from which bags are formed includes a force transmitter and a force sensor. The force transmitter transmits a force from the film to the sensor. The force sensor receives the transmitted force and provides a force signal. A controller receives the force signal and provides a seal signal. The the force sensor may be an mechanical sensor, an acoustic sensor, a mechanical sensor, a vibration sensor or a piezoelectric sensor.

Abstract: To predict residual settlement quantity and residual horizontal deformation quantity of ground where a liquefaction phenomenon has occurred due to earthquake. Soils in situ (stratum B to stratum D) are sampled from ground, and are made to be element test object stratums. A stratum whose characteristic is well-known, or the like may be substituted for a numerical model (stratum A). Next, setting of input conditions is performed, and vertical stress, horizontal stress and initial shear stress, which are equivalent to applied load that the ground at a depth of the point suffers, are worked on to each stratum. This recreates a stress status of soil before earthquake occurs. Then, shear displacement and the movement quantity of interstitial water by earthquake are given to the test piece, and the quantity of shear stress and pore water pressure, which have occurred, is obtained.

Abstract: A vibration testing system using acoustical waves having a testing unit including a main enclosure defining a main acoustical cavity and having a baffle provided with a main opening which is aligned with a set of acoustical insulation bands receiving an article to be tested that are clamped on a fixture secured to the baffle, so that the main opening is substantially closed by the article and the acoustical insulation bands. The apparatus includes a main acoustical source comprising a main acoustical transducer such as a loudspeaker which is acoustically coupled to the main acoustical cavity, and a subsystem for driving the loudspeaker which generates acoustical waves imparting vibration to the article accordingly. The apparatus preferably also includes a further acoustical source in the form of one or more further loudspeakers facing the main loudspeaker with the baffle extending therebetween, the further loudspeakers showing complementary frequency operating ranges.

Abstract: A mechano/electrical sensor senses force or vibration and delivers at least one electrical signal that is a function of the sensed force or vibration. The sensor has at least one inner body supported by at least one piece of electric support structure that, in turn, is suspended in a surrounding framework. Signal leads are provided from opposite lead polarizable sides of the at least one support structure.

Abstract: A method for diagnosing a fabrication machine for a semiconductor device, in which damage condition of components for fast driving can be recognized and failure of the components can be predicted, and the machine are provided. Vibration information of a drive member is sent from a motor controller for controlling a motor connected to the drive member to a machine controller. The vibration information is stored in an information storage in the machine controller and operated in an operational processor, and condition of the drive member according to the operation results is displayed on a display unit at any time. Therefore, when some failure occurs in the drive member, the specifics can be known with the display unit without need for connecting a special analyzer or PC to the fabrication machine for a semiconductor device. Consequently, the machine is capable for self-diagnosing, and thus trouble of the drive member can be prevented from happening.

Abstract: A method for testing micropower short-wave frequency-modulation digital radio includes the steps of providing at each test station on a production line with a steel cage that is adapted to accommodate a transmitter and a corresponding receiver for test; and providing between two steel cages located at two adjacent test stations with an interference generator that transmits signal-free carriers having the same frequency as that of electric waves transmitted from the transmitter to be tested. Electric waves outward radiated from a steel cage are first attenuated by the steel cage, then destructed by electric waves from the interference generator, and then attenuated again by a steel cage at another test station. Since the attenuated signal-free carriers are not decoded at the receiver in any other steel cage, radio tests could be simultaneously conducted at two adjacent test stations without being mutually interfered.

Abstract: A method and/or an apparatus for determining the dynamic response of a microstructure is disclosed. A piezocomposite ultrasonic transducer device formed of a piezoelectric material and a polymer material around said piezoelectric ceramic material is used to provide a pulsed bulk acoustic wave having a bandwidth of at least 20% to excite a microstructure. The microstructure is attached onto the transducer, and the pulsed bulk acoustic wave generated through the transducer in response to a pulse voltage excites the microstructure to vibrate. Meanwhile, the dynamic response of the microstructure can be monitored by a laser Doppler vibrometer, and shown by an oscilloscope.

Abstract: A method for inspecting concrete structures includes the steps of exciting the structure to be inspected with a mechanical device such as a chain, sensing resulting vibrations with an acoustical sensor such as a microphone that is not physically coupled to the structure, processing the received signals to exclude signals with frequencies outside of response frequencies of interest corresponding to defects desired to be detected, and examining the received signals. In preferred embodiments, the mean square of the processed signals are compared to a threshold. Areas for which the total energy across the frequency bands of interest exceeds the threshold correspond to defects such as delaminations. The received signals are collected from various locations on the structure. In preferred embodiments, the location of the received signals is also maintained.

Abstract: A device measures the propagation time for an acoustic wave in a continuous phase of a two-phase mix (28) comprising the continuous phase and a dispersed phase forming droplets (40) in the continuous phase. The device comprises an electro-acoustic transducer (12) capable of emitting acoustic waves (30) and outputting a reception signal of reflected acoustic waves, a signal pulse generator capable of determining a propagation time starting from signals output by the transducer, and an acoustic lens for focusing acoustic waves and the frequency of the acoustic waves being adjusted to cause reflection of the waves on the droplets of the dispersed phase, essentially located within a focusing area.

Abstract: A method for determining a remaining service life of switching contacts in an electric switching device. The method includes operating the switching contacts so as to produce structure-borne sound signals, capturing the structure-borne sound signals, performing a Fourier transform on the structure-borne sound signals in a plurality of discrete time windows so as to produce a sonogram, determining a plurality of function values using the sonogram, and evaluating the plurality of function values using an evaluation device. Also a electrical switching device including first and second switching contacts, a sound sensor configured to capture structure-borne sound signals produced by an operation of the first and second switching contacts, and an evaluation device configured to evaluate the first structure-borne signals so as to determine a remaining service life of the first and second switching contacts.

Abstract: A system includes a switching device, a sound device and an evaluation device. The switching device includes a housing and a contact system disposed in the housing, the contact system including a contact piece carrier and a contact piece disposed on the contact piece carrier. The sound device produces and captures structure-borne sound waves so as to determine an equivalent criterion for determining the remaining service life of the contact piece. The evaluation device evaluates the equivalent criterion.

Abstract: A method and/or an apparatus for determining the dynamic response of a microstructure is disclosed. A piezocomposite ultrasonic transducer device formed of a piezoelectric material and a polymer material around said piezoelectric ceramic material is used to provide a pulsed bulk acoustic wave having a bandwidth of at least 20% to excite a microstructure. The microstructure is attached onto the transducer, and the pulsed bulk acoustic wave generated through the transducer in response to a pulse voltage excites the microstructure to vibrate. Meanwhile, the dynamic response of the microstructure can be monitored by a laser Doppler vibrometer, and shown by an oscilloscope.

Abstract: A system for online monitoring the condition of a thermal barrier coating on the vanes and/or blades of a combustion turbine, or other forms of component deterioration affecting the acoustic properties of the vanes and/or blades. The system begins with a signal generator for transmitting a signal to an acoustic transmitter, and then to an acoustic waveguide secured within the turbine, adjacent to a vane. Acoustic waves passing through the vane's coating will have a certain magnitude and velocity when passing through an intact coating, which will change as the coating deteriorates. Additional variation of the acoustic wave will occur due to pressure pulses from passing blades, with the magnitude of the pressure pulses increasing as the blade's coating deteriorates. The acoustic waves are then received by a second acoustic waveguide.

Abstract: The present invention discloses a method and device for imaging based on the electroacoustic effect. The electroacoustic effect takes place when an ultrasonic wave passes through an electrolyte or colloidal suspension. The method and device of the present invention produces images whereby a sound wave is generated at the surface of an object, and, as the wave progresses through the body a voltage is generated in time corresponding to the electroacoustic response of the body at a point in space and time corresponding to the position of the ultrasonic wave in the body. As pulses are launched into the body at different points in space, the signal sensed by an amplifier is used to generate an image.

Abstract: The invention is directed to a method and apparatus for diagnosing deterioration of an article having at least a covering layer made from an organic polymer material. The method comprises (i) forming a data group for deterioration diagnosis comprising deterioration diagnostic characteristic values and corresponding ultrasonic wave propagation characteristic values for samples having different material specifications, (ii) propagating an ultrasonic wave through the covering layer of the article to measure an ultrasonic wave propagation characteristic of the covering layer, and (iii) determining a corresponding deterioration diagnostic characteristic from the data group for the ultrasonic wave propagation characteristic of the covering layer.

Abstract: An apparatus for ultrasonically examining a weld in a nuclear steam supply system includes an elongated guide rod for positioning within a pipe of the nuclear steam supply system. An ultrasonic transducer is positioned at an end of the elongated guide rod. A collapsible shoe encloses the ultrasonic transducer. The collapsible shoe includes a biasing mechanism to allow the collapsible shoe to pass through the pipe while the pipe is at a first circumference and while the pipe is at a second circumference. The collapsible shoe continuously contacts the pipe to establish ultrasonic coupling for the ultrasonic transducer.

Abstract: When electrodes on an electronic component and electrode portions on a circuit board are joined via bumps with the electronic component and the circuit board vibrated respectively, a vibration damping detect device and a deciding device detect damping of the vibration caused by a progress of joining between the bumps and the electrode portions, and then determine a good or defective of the joining on a basis of the damping of the vibration. Further, regarding an impedance of an ultrasonic oscillator, a movement amount of a nozzle, or a current supplying to a VCM, these waveforms during the joining are compared with waveforms of good joining thereof and then the good or defective is determined. According to the above constructions, the good or defective of the joining between the electronic component and the circuit board can be determined during the joining. Further, when a joining state becomes wrong during the joining, the joining state can be changed.

Abstract: A method and a system for measuring the mechanical vibrations of an object. In order to simplify the electronic circuit necessary for the measurement chain and to reduce its costs, this method and this system are characterized in that they comprise the processing of an input signal, representative of an acceleration or of a velocity related to a mechanical vibration of said object, said input signal having a frequency spectrum comprising a so-called low frequency band, situated below a so-called transition frequency, and a so-called high frequency band, situated above said transition frequency, said method and system carrying out said processing of said input signal by means of an electronic circuit for producing an output signal which, in said low frequency band, corresponds to the mathematical integral over the time of said input signal, and, in said high frequency band, corresponds to said input signal.

Abstract: The method of and a device for using this method, on equipment or assigned to equipment for working a material, for investigating and identifying the nature of the material, which is to be worked and for making available at least one operating parameter for the optimized pre-setting of the working equipment, provides for the use of a sensor, preferably assigned directly to the working tool, such as a hammer drill, in order to detect shock waves generated or induced in the tool. From the shock wave signal measured, at least one distinguishing feature characteristic of the material to be worked, is extracted and evaluated for the comparative classification of the material by means of an algorithm. Preferably, an external force, especially the contacting force, acting on the working equipment, is taken into consideration for the algorithmic evaluation.

Abstract: A sound detector device for locating and diagnosing sound in a motor vehicle includes a headphone and a plurality of directional microphones. The sound detector device also includes a main unit having a circuit operatively connected to the headphone and the directional microphones for allowing an operator to diagnose sound in the motor vehicle.

Abstract: An ultrasonic testing method uses surface waves to prevent false detection of primary cracks, to lower the level of structural noises from grain boundaries, and to improve the detectability in the ultrasonic testing by surface wave testing of hot rolling rolls. A surface wave probe 10 capable of transmitting and receiving a surface wave is provided with a piezoelectric element 10A, a resin wedge 10C disposed on the front surface of the piezoelectric element 10A and a damping block 10B disposed on the back surface. The surface wave probe 10 is driven to produce a short pulse having a pulse length being at most 2.5 times the wavelength of the surface wave to be produced. A coupling liquid medium is supplied to the probe 10 in accordance with the peripheral speed of the roll to be tested. Depending on the height of the reflected waves measured, the grinding allowance of the roll is determined, and the roll is ground according to the thus-determined grinding allowance.

Abstract: In a method and a system for visualizing the position and orientation of an object that is penetrating, or that has penetrated, into a subject, a first set of image data are produced from the interior of the subject before the object has penetrated into the subject, a second set of image data are produced from the interior of the subject during or after the penetration of the object into the subject, the sets of image data are connected and are superimposed to form a fused set of image data, and an image obtained from the fused set of image data is displayed. The system has an x-ray computed tomography apparatus, and an x-ray apparatus, and/or an ultrasound apparatus for producing the first and second sets of data, respectively.

Abstract: The adaptive body bending estimator comprises a band pass filter which receives an accelerometer signal from a missile's accelerometer. The band pass filter, which has a bandpass of 25-70 hertz, rejects frequencies which are not of interest. The band-passed signal is then supplied to a notch filter bank comprising six notch filters within a frequency range of between 42 hertz and 55 hertz. The six notch filters are centered at different frequencies, the frequencies being 42 Hz, 44.32 Hz, 46.78 Hz, 49.37 Hz, 52.11 Hz and 55.00 Hz. The notch filters reject signals at these frequencies. The signals from the filter bank are supplied to an absolute value generator which generates an absolute value for each signal. The absolute value of each signal is passed through a low pass filter bank. The low pass filter bank processes these absolute value signals providing a time weighted average for each signal. The low pass filter bank provides its output signals to a find frequency module.

Abstract: A combine return grain monitor for monitoring grain flow in a return grain path and for directing an electrical signal to a meter located in the cab of the combine to provide the operator with continuous visual indication of the grain being transported in the return grain path. A wedge-shaped horn is positioned on a wall of the combine just below the opening through which the return material is dropped to the return grain cross auger. Much of the tailings material falls against the outer surface of the wedge-horn before falling on through the opening onto the return grain cross auger. The wedge-horn mechanically amplifies sound as material strikes its outer surface. A microphone, located inside the wedge-horn, picks up the amplified sound of material striking the outer surface of the wedge-horn. The microphone provides an electrical signal which is directed to a meter located in the cab of the combine.

Abstract: A device is described which combines Acoustic and Electroacoustic spectrometers to characterize both particle size distribution and zeta potential for concentrated dispersed systems.The Acoustic Spectrometer measures both attenuation and sound speed for multiple frequencies using each measurement to help optimize and correct the other. The attenuation spectra is used to calculate particle size.The Electroacoustic Spectrometer measures Colloid Vibration Current (CVI), correcting the measured value using attenuation and sound speed data from the Acoustic Spectrometer. The Colloid Vibration Current is used to calculate zeta potential taking into account the particle size calculated from the acoustic measurement as well as particle interaction.Sound speed and multiple frequency CVI measurement provide additional experimental data to check the validity of the data.

Abstract: An electronic circuit serving as an interface between a piezoelectric transducer and a circuit for processing a measuring signal provided by said transducer, said electronic interface circuit serving for providing a constant direct current to said piezoelectric transducer, and for pre-processing an electric signal provided by the transducer via a voltage modulator, said electronic interface circuit being connected to said voltage modulator by a cable having two terminals at each end, the two terminals at a first end of the cable being connected to the output of the voltage modulator and the two terminals at a second end of the cable being connected to said electronic interface circuit.