Abstract: Degradation of the lubricant due to contamination of the lubricant with wear particles or moisture, which greatly affects the service life of rolling bearings, can be detected in a cost-effective manner through the use of a resonance frequency band signal or high-frequency signal of an accelerometer, and the service life of a rolling bearing can be estimated with high precision at an early stage on the basis of the detected state of the wear particles and lubricant.

Abstract: In a non-destructive test instrument, there is provided a time variable gain (TVG) amplifier wherein the gain of the amplifier is dynamically changed to optimize the amplitude of a flaw echo signal. The TVG digital memory for a given TVG curve specifies and controls not only the start gain value, and the end game value, but the gain rate of change slope as well to generate TVG curve line segments.

Abstract: The invention relates to a method for determining the threshold value of screens which enable an evaluation of a sound coupling during the ultrasound testing of a series of spot welding joints of a selected type. Initially, a geometrical minimal thickness dMin is established for the spot welding joints. At least one echo of the front surface (entrance echo) is received in addition to one echo of the first reflection on a rear wall of the spot welding joint (first rear wall echo) and at least one further (n-th) rear wall echo. The propagation time tMin of the ultra sound pulse is defined for the path to the front surface to the rear wall and back to the front surface at a minimal thickness dMin and a propagation time tT for the total thickness. A first screen (B1) is set for the signal of the rear wall echo, starting at a moment in time t1S=tE+tMin?tSA and ending at a moment in time t1T=tE+tT+tSE, whereby tSA and tSE are additional small security measures.

Abstract: An ultrasonic distance measure includes: transmitting and receiving ultrasonic transducers with changeable resonant/resonance frequencies; a driving section generating a frequency-modulated drive signal to drive the transducer and transmit an ultrasonic wave; a transmitting control voltage generating section for generating a control voltage to change the resonant/resonance frequency of The transducer and applying it to the transducer in transmitting the ultrasonic wave; a receiving control voltage generating section for generating a control voltage to change the resonant/resonance frequency of the transducer and applying it to the transducer when a controllable amount of time delay has passed since The drive signal was generated; and a receiving section for sensing the intensity of a signal received as the ultrasonic wave at the transducer.

Abstract: There is described apparatus for inspecting a non axi-symmetric elongate body comprising: at least one exciter array having a plurality of wave exciters operable to couple to an exterior surface of said elongate body; a driver unit operable to generate driving signals to excite said plurality of wave exciters wherein each driving signal to a respective wave exciter of said array is weighted with respect to driving signals to other wave exciters in said array such that a guided acoustic wave mode is excited; a receiving unit having a plurality of wave exciters in said array such that a guided acoustic wave mode is excited; a receiving unit having a plurality of wave receivers capable of receiving reflected guided acoustic waves; an analysis unit operable to analyse received waves to assess a condition of said non axi-symmetric elongate body.

Abstract: A method and apparatus for detecting and monitoring fractures in a structure by monitoring acoustic energy transmitted within the structure by receiving continuously over a period of time electrical signals from a plurality of acoustic tranducers carried by the structure in a pulse processor to form data bursts from pulses in the signals and deriving, for each of a plurality of the data bursts, delta-t values representing the differences between burst arrival times at each sensor, the delta-t values forming a delta-t pattern, and generating a damage indication signal when the delta-t pattern is repeated to a predetermined degree.

Abstract: The channeled wavefield transformer enables multi-dimensional wavefield signal processing which leads to significant expansion of the engineering field of electronic signal processing. The term “wavefield” is used to indicate one or more waves that operate in at least two dimensions of space where spatial form of a wave can be represented by a wavefront that is a surface of points of equal phase. This transformer produces an output wavefield in a clear medium in response to an arbitrary input wavefield. This is carried out using multiple channels that connect input sensing devices to respective output transmitting devices. The input devices are arranged along an input surface and the output transmitting devices are arranged along an output surface. An output wavefield emerges from the output surface to propagate in an output wavefield space.

Abstract: An ultrasonic inspection device is constructed of an ultrasonic scanning unit, drive unit for the ultrasonic scanning unit, and a computing unit. The ultrasonic scanning unit is provided with an ultrasonic probe for two-dimensionally scanning a surface of a specimen with an ultrasonic wave through a medium such as water for the ultrasonic wave. The computing unit controls the ultrasonic scanning unit via the drive unit and performs an inspection for any flaw in a film formed on a surface of abase material as the specimen. From the ultrasonic probe to the specimen, an angled incident wave is transmitted such that a leaked elastic surface wave is induced, and a leaked wave from the specimen is received at the ultrasonic probe. When the adhesion is good, the reception level of the leaked wave becomes low. When the adhesion is poor, on the other hand, the reception level of the leaked wave becomes high.

Abstract: If a difference between a value evaluated by prorating a sum of an average value of a signal outputted from a signal processing portion within a second predetermined time before a start of a pseudo drive and an average value of the signal outputted from the signal processing portion within a third predetermined time after an end of the pseudo drive, and an average value of the signal outputted from the signal processing portion within a first predetermined time from the start to the end of the pseudo drive does not fall within a predetermine value, the sensor error is determined.

Abstract: A method for monitoring and measuring the buildup of deposits on the inner surface of a pipeline containing flowing fluid comprises (a) transmitting a first acoustic signal into the pipeline through the pipeline wall, (b) receiving echoes of the transmitted signal, and (c) determining from the received echoes how far from the pipeline inner surface the interface between the deposits and the flowing fluid lies. An alternative method for monitoring and measuring the buildup of deposits on the inner surface of a pipeline containing flowing fluid comprises (a) transmitting a first acoustic signal into the pipeline through the pipeline wall, (b) receiving echoes of the signal, and (c) using the Doppler frequency shift of the received echoes to determine how far from the pipeline inner surface the interface between the deposits and the flowing fluid lies.

Abstract: An obstacle detecting system for vehicles has an ultrasonic vibrator having a vibration plate and mounted on a vehicle to transmit and receive an ultrasonic wave. An obstacle is detected in response to an output signal of the ultrasonic vibrator. When the temperature around the ultrasonic vibrator is below a predetermined temperature corresponding to snowfall, the system calculates a ratio of a period of reverberating vibration of the ultrasonic vibrator relative to a predetermined time period following an ultrasonic wave transmission, and determines accumulation of snow when the calculated ratio exceeds a predetermined time ratio. The system notifies an abnormality of the ultrasonic vibrator arising from the accumulation of snow.

Abstract: The invention relates to a method and apparatus for measuring a speed of an ultrasonic: wave propagated in a sample, even if there are bubbles in a sample. And it presupposes an ultrasonic speed measuring method for seeking a sonic speed in a sample in accordance with the propagation time of an ultrasonic wave propagated between an ultrasonic transmitter and an ultrasonic receiver by transmitting the ultrasonic wave from the ultrasonic transmitter. The apparatus of this invention is arranged that continuous oscillating waves are oscillated synchronizing the phase only with the receipt timing of at least one of receiving waves received by the ultrasonic receiver at every transmitting waves, and according to the continuous oscillating waves it is possible to measure the period of pulses oscillated by the local oscillator for determining the transmit timing.

Abstract: An ultrasonic imaging system including an aberration correction system uses a harmonic component of the fundamental transmitted frequency for imaging, or for aberration correction, or both. By properly selecting the frequency pass bands of filters used in the image signal path and in the aberration correction signal path operating advantages are provided. The aberration correction values may be calculated concurrently with image formation.

Abstract: An obstacle detecting system for vehicles has an ultrasonic vibrator having a vibration plate and mounted on a vehicle to transmit and receive an ultrasonic wave. An obstacle is detected in response to an output signal of the ultrasonic vibrator. When the temperature around the ultrasonic vibrator is below a predetermined temperature corresponding to snowfall, the system calculates a ratio of a period of reverberating vibration of the ultrasonic vibrator relative to a predetermined time period following an ultrasonic wave transmission, and determines accumulation of snow when the calculated ratio exceeds a predetermined time ratio. The system notifies an abnormality of the ultrasonic vibrator arising from the accumulation of snow.

Abstract: The invention relates to an ultrasonic measuring instrument comprising a housing which contains a transducer for transmitting and receiving ultra-sound waves, and a rotatable mirror placed inside the housing for directing ultra-sound waves coming from the transducer through a tapering window comprised in the housing to an object of measuring outside the housing, and for directing ultra-sound waves which are reflected by the object of measuring and which enter the housing through the window to the transducer. Around, and rotating with the mirror a tube is provided, comprising a recess for the passage of ultra-sound waves.

Abstract: A digital bond tester operating at frequencies in the kHz range and relying upon vibrational modes which can excite all or substantial portions of the test object.

Abstract: A configuration flexible computer-controlled ultrasonic diagnostic test equipment arrangement for examining large turbine rotors incorporates improved ultrasonic signal "pulser-receiver" circuitry that is used to drive one or more an ultrasonic transducers and to receive and amplify ultrasonic returns from a specimen under test. The improved pulser-receiver circuitry comprises both an ultrasonic pulse generating circuit and an associated ultrasonic return signal linear amplification circuit. The pulse generating circuitry and the ultrasonic return signal amplification circuitry are modular and functionally independent of each other and, consequently, may be used together in the testing system or as stand-alone instrumentation. Overall ultrasonic diagnostic system flexibility is significantly enhanced by providing improved pulser-receiver circuitry with digitally driveable computer control inputs in addition to manual controls to enable selecting initial parameters and transducer position settings.

Abstract: A two-dimensional ultrasonic transducer for forming images. The transducer has a plurality of transducer elements for producing ultrasonic bursts in a predetermined manner, and receiving reflected ultrasound from the subject under examination due to the ultrasonic bursts. The plurality of transducer elements are arranged in an array into columns and rows, the columns of the transducer elements arranged in a scanning plane for scanning the subject under examination in order to form a two-dimensional profile of the subject, and the rows of the transducer elements having groups of symmetrically arranged transducer elements being oriented in a elevational plane. Each of the groups of symmetrically arranged transducer elements are mechanically arranged to have a focus at specified locations distant from the transducer which is within the subject under examination.

Abstract: In a method for storing vibration waveform data sequentially detected by a vibration sensor. The vibration storing method includes detection of a reference level terminal point (P.sub.3) between a preestablished reference level and a vibration waveform. The detected reference level terminal point serves as a trigger. Also, vibration waveform data from a predetermined point (P.sub.0) before a reference level starting point (P.sub.1) to a predetermined point (P.sub.4) after the reference level terminal point (P.sub.3) are stored in a memory. A first preliminary memory and a second preliminary memory are utilized so that the vibration waveform data from those two memories are alternately transferred and stored.

Abstract: A measuring apparatus uses a variable and fixed frequency pulsed phase locked loop to measure the phase shift caused by a delay path to a high degree of accuracy. This accurate measurement of total phase change through greater than 360 degrees allows the apparatus to measure strain in bolts or other materials. The apparatus is able to identify features on a waveform through pattern recognition, and measure untracked phase differences with better reliability than simple thresholding techniques permit.

Abstract: A sensing apparatus includes a sensor package for generating an output signal responsive to a sensed quantity. The sensor package includes a surface acoustic wave (SAW) sensor and driver driver circuit mounted within a common package to facilitate connection to the associated processing apparatus. More particularly, the SAW sensor has a delay related to a sensed quantity, but generates undesirable reflections responsive to pulses propagating therethrough. The driver is controllable for delivering a series of pulses to the SAW sensor with each pulse having a random phase to thereby reduce effects of the undesired reflections of the SAW sensor. The sensor package also preferably includes connectors carried by the package for facilitating connection of the sensor package to the associated processing apparatus to permit susbstitution or replacement, for example.

Abstract: A sensing apparatus includes a pulse recirculating circuit operatively connected to at least one ultrasonic delay sensor or other device for recirculating pulses therethrough, and a measurement difference output circuit for generating an output signal based upon a difference between first and second measurements of the at least one ultrasonic delay sensor. The pulse recirculating circuit preferably comprises a pulse generator for generating a series of input pulses to the ultrasonic delay sensor, and a pulse detector for detecting a series of output pulses after propagation through the ultrasonic delay sensor. Moreover, the measurement difference output circuit preferably includes an up-down counter for counting pulses during the first measurement in one direction and for counting pulses during the second measurement in an opposite direction. Accordingly, the remaining counter contents represent a difference in delay between the first and second measurements.

Abstract: A beam forming and focusing processing circuit for use in an ultrasound imaging system. The system incorporates a plurality of the processing circuits which differentially delay imaging signals in order to generate an output in which the imaging signals from each circuit implement the desired differential delay. Each of the processing circuits include a first delay line having a plurality of delay units operable for receiving the imaging signals and converting same into sampled data. A selection control circuit is operable for reading the sampled data from a selected first delay unit of the first delay line so as to correspond to a selected first time delay to accommodate fine delay resolution of the imaging signals. A second delay line having a plurality of delay units is operable for sensing the sampled data from the selected first delay unit.

Abstract: An apparatus includes an ultrasonic delay sensor or device having a delay related to the sensed quantity; a pulse recirculating circuit for recirculating pulses through the ultrasonic delay sensor for generating a pulse repetition signal having a frequency related to delay of the ultrasonic delay sensor; and an output circuit for generating an output signal related to delay in the ultrasonic delay sensor based upon a difference in phase velocity between the pulse repetition signal and a time base signal. The output circuit preferably includes a first multiplier for multiplying the pulse repetition signal by a first number, and a second multiplier for multiplying the time base signal by a second number to have a frequency substantially the same as the multiplied pulse repetition signal. The effects of undesired reflections in the ultrasonic delay device may also be reduced or suppressed. Method aspects of the invention are also disclosed.

Abstract: In an ultrasonic inspection apparatus for detecting a flaw present in a target object (2) on the basis of an echo signal (b) from the target object (2), a high-frequency echo signal (b) output from an ultrasonic transmit-receive unit (1) is A/D-converted at a high sampling frequency (f.sub.S) in only a predetermined measurement time interval (T.sub.M) in a repetitive period (T.sub.O) of an ultrasonic pulse (a) and is temporarily stored in a storage unit (12). Thereafter, the sampling data is read out at a read frequency (f.sub.R) lower than the sampling frequency (f.sub.S). A digital signal process for noise reduction using a first digital filter (18) or a synchronous adding/averaging circuit (27) is performed to only data in the measurement time interval (T.sub.M). As a result, noise included in the echo signal (b) is considerably reduced while on-line inspection is kept performed.

Abstract: A method and apparatus for discriminating a valid return pulse from noise in a return signal received by an ultrasonic transducer in response to an interrogating pulse transmitted into a wall of a gas pipe by an ultrasonic transducer of a scan assembly. A discriminator is provided to compare the return signal with adjustable reference voltage thresholds which are continually adjusted by a discriminator computer in accordance with the noise characteristics of the return signal.

Abstract: Apparatus (10) for performing ultrasonic flaw testing of a material (M) or assembly. A pulser (28) generates an electrical pulse having defined characteristics. A transducer (12) converts the signal to an ultrasonic pulse, propagates the pulse through the material or assembly, receives an echo the characteristics of which include reflections off flaws or discontinuities in the material or assembly, and converts the echo into an electrical reply signal. The transducer is selectable from among a number of transducers. A processor (32) processes the reply signal to produce a visual display representing the amplitude of the reply signal for a range of propagation times (distances) into the material. A visual display (16) displays the processed electrical signal. A correlation module (42) generates a gate signal which is visually displayed (at 38) with the processed electrical signal. The gate signal corresponds to a maximum amplitude value which represents the maximum flaw size allowable for the test.

Abstract: A preamplification and impedance matching circuit for an electromagnetic acoustic transducer includes an impedance matching section of the circuit having input terminals for receiving radio frequency power from a radio frequency power source. A matching transformer, which is a step-down transformer, is operatively connected to the input terminals. Diode networks are operatively connected to the matching transformer and output terminals which lead to the coil of the transducer. Signal responses emitted by the transducer coil are transmitted to a preamplifier section of the circuit. Choke coils or resistors are used to limit radio frequency power entry into the preamplifier section of the circuit.

Abstract: The rolling element bearing condition testing method uses acceleration signals at frequencies over 1000 Hertz and employs band-pass and digital filtering and envelope detecting techniques. The testing method measures the vibration signals generated by the rolling element bearing in the frequency range containing the majority of the rolling bearing energy, typically from 2,000 Hertz to 15,000 Hertz, next optionally de-modulates those signals, and then uses digital filter techniques to remove the interference, either from the de-modulated acceleration signal or from the raw acceleration signal.

Abstract: A method and apparatus for the ultrasonic inspection of acoustically "noisy" specimens, such as those having intrinsically coarse grain structure (e.g., turbine rotor parts made of superalloy compositions) employs several types of ultrasonic diagnostic measurement techniques, including at least: "Pitch-Catch" analysis and "Pulse-Echo Axial Long-Wave" analysis. When a Pitch-Catch technique is utilized, a "through-transmitted" sound wave is acquired for each specimen tested and used as a calibration standard to normalize ultrasonic inspection test data for that specimen prior to any automated defect/flaw detection and sizing processing. The through transmitted sound wave is also used to equate the amplitude of "indications" (i.e., significant detected ultrasonic reflections) to that of a standardized theoretical reflector of known size (e.g.

Abstract: An ultrasonic diagnostic apparatus has a probe having a plurality of channels, a receiving circuit for dividing receiving signals from the probe to deliver them in the form of "K" (K being an integer which is 2 or more) blocks each having a predetermined number of channels, a selector circuit for selecting signals corresponding to respective ones of the blocks from output signals of the receiving circuit and delivering the selected signals, a signal distributor for selecting the output signals of the receiving circuit in the mode of single beam reception and selecting the output signals of the selector circuit in the mode of simultaneous parallel beam reception, "K" delay circuits connected to outputs of the signal distributor and each having the predetermined channels, and a switch for switching the "K" delay circuits to series connection in the mode of single beam reception and switching the "K" delay circuits to parallel connection in the mode of simultaneous parallel beam reception.

Abstract: A measuring apparatus using an ultrasonic wave according to the invention transmits an ultrasonic wave pulse into a specimen, receives the echo reflected by the specimen and converts it into an electric signal. The components of the electric signal that represent the wave reflected by the specimen and contain data on the state of the specimen are extracted by a gate circuit. The components obtained by the gate circuit are converted into a power spectrum by a circuit for performing a Fourier transformation. The thickness of the specimen and/or the flaking state of the specimen can be determined from this power spectrum.

Abstract: An ultrasonic system for determining the quality of concrete under water hout inaccuracies caused by electromagnetic interference from the ultrasonic generator. An ultrasonic generator applies pulses to the concrete. An ultrasonic detector detects the ultrasonic pulses and produces corresponding signals that are indicative of ultrasonic pulses that have passed through the material. Signal processing circuitry processes the signals to determine the transit time of the ultrasonic pulses through the material. The signal processing circuitry is disabled for a predetermined time after application of each ultrasonic pulse to the material to prevent noise produced by the means for applying ultrasonic pulses to the material from entering the signal processing circuitry and causing spurious measurements.

Abstract: The presence of pipeline connections can be checked by the transmitting of acoustic signals from a transmitter to an acoustic sensor within the pipe. This method is used in particular in the manufacture of cigarettes.

Abstract: The present invention relates to a hydrophone specifically designed for use in high pressure shock wave fields, comprising a thin piezoelectric polymer film secured to a rigid hoop structure, having a centrally located active element and two conducting leads extending from the active element on each side of the film. Under the action of high pressure shock waves, the conductive material which makes up the active area electrode and the conductive leads is slowly removed, altering the hydrophone's sensitivity and eventually rendering it unusable. The present invention provides an improved design for a hydrophone which monitors the loss of electrode and lead integrity due to shock wave action so that the hydrophone may be replaced before it produces invalid readings. The leads on each side of the centrally located active element are electrically switched to measure the resistance between the leads and the central portion.

Abstract: A method and apparatus is reported for detecting inhomogeneities in semi-plastic substances such as toilet bars containing soap. An ultrasound probe is utilized to test the substance at an exit orifice of an extruder. Best results are obtained by utilizing a ceramic ultrasonic probe, rectangular in shape including a transducer having a concave curvature on a lower surface thereof. The probe includes a theromplastic delay material. Ultrasonic waves directed through the probe preferably have a frequency between 1 and 2.25 MHz. Wedging of the extruded substance is also useful to improve contact with the probe as it passes through the extruder exit orifice.

Abstract: A coextruded zirconium tube and tube liner are monitored along their lengths by well known ultrasonic measurement techniques that are modified by the blocking out of extraneous signals at opposite sides of a timing gate that varies in width according to variations in the width and shape characteristics of successive points along the length of such coextruded tube and liner. The blocking of such extraneous signals enables a normally very weak signal representing the interface between tube and tube liner to be identified and used, together with a group of stronger signals representing the inner surface of the tube liner, in monitoring tube liner thickness and characteristics by a sonic wave traversing the distance across the timing gate.

Abstract: The intensity profile of an ultrasound beam in an ultrasound imaging system is adjusted by driving the individual piezoelectric crystals with drive signals having adjustable pulse durations. The duration of the drive pulse determines the frequency spectrum of the pulse and therefore determines the amplitude of the emitted ultrasound wave. The pulse durations may be selected such as to compose a desired profile of the ultrasound beam.

Abstract: An ultrasonic imaging system which is used to provide contact imaging of a component. A transducer is scanned across a workpiece to collect image data from a scan area comprising a plurality of pixels. Means for resiliently carrying the transducer with two separate degrees of freedom maintain a tight acoustic coupling between the workpiece surface and the transducer. The image data relating to each position in the scanned area describe the amplitude of a reflection and its depth from a reference. Means are provided for easily varying the size of the image area while the number of pixels remains constant. The system provides a real-time visual display of the scanned area while the transducer is moving over the area in contrast as either a grey scale or a color scale for each pixel. An automatic calibration mode for the sytem is provided as another feature to remove acoustic delay, caused by transducer coupling, from the image data.

Abstract: The initial contact of a rotating milling tool to a workpiece is detected in the presence of spurious noise spikes by digitally processing samples of a preprocessed vibration signal concurrently through basic tool touch detection logic and milling tool touch detection enhancement logic, and generating a touch indication if either logic set is satisfied. The basic logic detects a continuously increasing signal level higher than a threshold set above background noise. The milling logic detects an above-threshold signal sample and sets up an acceptance window about the expected time of contact of the next cutter. Tool touch is declared when an above-threshold signal occurs during the window; the milling logic is reset by a noise spike in the interval before the window starts. The basic logic detects tool touch in a dense spiky noise situation.

Abstract: In order to replace acoustic lenses, frequency units corresponding to frequencies used by the acoustic lenses and housing transmitted pulse generating means, circulators and receiving means can be selected and the signal of a gate opening at a timing at which ultrasonic waves of a sample return can be selected.

Abstract: A Machine Tool Monitor detects the sudden increase in vibration signal level when a slowly advancing cutting tool first touches the workpiece. The delay to a tool touch decision is reduced while still avoiding false alarms on high amplitude single-peaked and multi-peaked noise spikes. Samples of the preprocessed analog vibration signal that are above a low threshold level are analyzed by digital tool touch detection logic. The signal slope polarity is determined by comparison of a new sample to the tracking mean, or by sample-to-sample amplitude comparisons, and presented to an up/down counter. A tool touch alarm is generated when the positive slope counts exceed the negative slope counts by a preset number slightly greater than occur in a time period from the start of a noise spike until its peak amplitude is passed.

Abstract: An ultrasonic scanning apparatus includes a transducer array made up of a plurality of ultrasonic transducer elements and delay lines connected through individual switch elements to the transducer elements. The transducer array, the switch elements and the delay lines are each divided into two blocks. The ultrasonic echo signals derived from these blocks are summed through the corresponding delay lines. One of the summed signals of both the blocks is applied through a fixed delay line to an adder. The other of the signals is directly applied to the adder. The adder adds together these echo signals.

Abstract: A phased array of transducer elements in an ultrasound imaging system is selectively directed by grouping transducer elements in the array to form a plurality of groups of adjacent transducer elements. Electrical signals in each group are mixed with a modulation signal of a fixed frequency, the modulation signal being selectively phased delayed for each electrical signal in the group depending on the angle of direction of a reflection point in an imaged volume. The mixed electrical signals for each group are then summed and selectively timed delayed, and then all time delayed and summed electrical signals are then summed to form an image beam.

Abstract: The present invention is a multiline beamformer for use in a medical ultrasound scanner using a phased array transducer. Lines of ultrasound energy are generated having a pressure at the array aperture corresponding to sin (.pi.x)/.pi.x, where x is the normalized distance of the array element measured from the center of the array. This transmitted energy creates a flat field in space which can then be received in multiple receive lines, using bundled, parallel time delays.

Abstract: A system and method for monitoring vibrations of a machine tool metal-cutting tool insert and interpreting them to promptly detect the initial touch to the workpiece and signal the tool to stop advancing before marring the surface. The signal generated by a sensor such as an accelerometer is preprocessed to eliminate lower frequency machine noise and detect the energy in a higher frequency band, then sampled and analyzed by digital circuitry. In order to avoid false alarms on high amplitude spiky noise pulses generated by traverse operation of the machine tool, the tool touch alarm is delayed longer than the maximum duration of the noise pulses. Two techniques are given to ignore the noise spikes while still detecting the tool touch signal.

Abstract: Continuous wave (CW) Doppler imaging employs a linear array of transducer elements with a first plurality of elements functioning as an ultrasonic wave transmitter and a second plurality of elements functioning as a receiver of the reflected ultrasonic wave. Time delay circuitry connected to the transmitter and receiver elements define the beam focus and beam steering of the ultrasonic wave.

Abstract: An ultrasonic flaw detecting technique in which reflection echoes of ultrasonic waves transmitted from a plurality of vibrator elements are received, and a composite signal obtained by composing the reception signals is supplied to a composite signal reception processing circuit. A method and an apparatus in which the existence of the composite signal is detected at a first time point at which the composite signal based on the reflection echoes from an inspection target in a main lobe can be detected and at a second and a third time point which are in advance of and later than the first time point respectively and at which the composite signal based on the reflection echoes from an inspection target in the main lobe can not be detected, so that when the existence of the composite signal is detected only at the first time point, it is determined that the composite signal is that based on the reflection echoes from the inspection target.

Abstract: An ultrasound tranceiver providing enhanced imaging by selective filtering of the received signal to provide a variable frequency, constant bandwidth filtering of the received echo signals. The resulting signals are then detected to produce a signal, which when displayed, has a reduced number of false multiple images and enhanced signal quality from the deeper tissue discontinuities. Additionally, the received signal is detected in quadrature by reference to a simulated carrier pilot tone having a nonconstant frequency relationship to the transmitted signal. The resulting signal is post-processed to provide information which is used to display structural features, and in addition, the velocity profile of blood flow. The structure and velocity image information is superimposed to provide a composite signal wherein the static and dynamic characteristic of a patient is completely reported to the observer.

Abstract: An ultrasonic defect detection assembly (A) and an elongated workpiece (B) are mounted for relative movement. A mechanical assembly (C) provides relative movement between the workpiece and the examination assembly. An electronic circuit and display (D) produces a visual display indicating the relative position of the workpiece and the examination assembly, particularly the relative positions at which the examination assembly detects defects. A transmitting ultrasonic transducer (30) and a receiving ultrasonic transducer (38) are acoustically coupled with the workpiece, one being mounted at a preselected position on the workpiece and the other being mounted for relative movement with the examination assembly. The relative position of the workpiece and examination assembly is determined by measuring changes in a characteristic of the acoustic wave traveling between the transmitting and receiving transducers.