Abstract: A method and apparatus for monitoring cracks of a rotatable body by detecting cracks by measuring accoustic emission signals and evaluating the depth of cracks from the result of the comparison of assumed vibrations of the rotatable body and its measured vibrations. By this method and apparatus not only the beginning of cracking of the rotatable body, but also the progress of cracking on an online basis can be detected and monitored.

Abstract: An ultrasonic probe for measuring the velocity of sound in a liquid consists of a tube (12), closed at its lower end, and arranged to extend into the liquid, a reflector (20) alongside the tube but spaced away from it, and a source (30) of ultrasonic waves in the tube. The source is arranged so as to cause an ultrasonic beam to propagate through the tube wall (16), to traverse the liquid occupying the space between the tube (12) and the reflector (20), and to be reflected back. The source (30) can be scanned along the length of the tube to ascertain the variation of liquid properties, the position of the liquid surface, and the presence of emulsion layers and precipitates. The wall of the tube through which the ultrasonic beam emerges may be plano-concave in cross-section to enhance the ultrasonic beam intensity in the liquid.

Abstract: In an ultrasonic microscope, if a plane to be observed of a sample is not parallel with a scanned plane formed by an ultrasonic wave beam, an interference with a reflected wave will be produced and no clear picture image will be obtained. Therefore, it is indispensable to adjust the inclination of the sample stand as an initial adjustment before the observation.

Abstract: An apparatus for examining objects by ultrasonic echography comprising an ultrasonic transmitting transducer (10) and an ultrasonic receiving transducer (20), with which are associated a transmitter stage (30), a receiver stage (40) constituted by a channel (100) for processing the echo signals reflected to the receiving transducer by the obstacles they meet in the said region and a storage and/or visualization stage (60), characterized in that the transmitting transducer (10) is at the same time a receiver and in that the receiver stage (40) also comprises a channel (200) for processing the output signals of the said transmitting/receiving transducer (10) thus formed and a subtraction device (500), whose output is connected to a first input (560) of the storage and/or visualization stage and whose two inputs receive the output signals of the said channels (100) and (200) representative of the real and theoretical travelling times, respectively, between the transducers.

Abstract: There is disclosed herein an apparatus and method for producing a substantially uniform acoustic field for use with a liquid crystal cell to produce a substantially artifact-free image of an object. The apparatus and method include moving an ultrasonic transducer toward and away from an object, a distance effective to cause adjacent constructive and destructive zone patterns to in effect overlie each other. The period of reciprocation is less than the time for onset of image decay, but greater than the image rise time so as to assure image formation. In addition, the frequency and/or phase of the acoustic energy can be varied so as to further enhance the image.Electro-mechanical and piston driven embodiments are disclosed for reciprocating the transducer.

Abstract: A method of reliably detecting flaws in a thick wall steel pipe with an ultrasonic beam in which flaws of the internal surface of the pipe are detected using a shear wave mode. The transmitting probe is disposed slantingly relative to both the longitudinal and transverse directions of the pipe so that the shear wave emitted therefrom is incident onto the pipe at a refraction angle of 35 to 70 degrees, whereby the beam inside the walls of the pipe is made to impinge on surface flaws of the inner surface of the pipe at an angle in the same range.

Abstract: A new structure of vibration sensor mainly comprising two metal conducting plates on its body, one of which is installed with an adjusting screw and the other with a fixing screw connecting to a vibrating spring which is connected to a hopper conductor at the other end. The adjusting screw is located in such a manner that its tip is in the middle of the hopper conductor, so that when the vibrating spring detects shock signals it causes contact between the hopper conductor and the adjusting screw.

Abstract: A device for estimating the number and the mass of particles borne in a fluid stream comprises a novel target on which the particles impact at a constant angle thereby generating acoustic signals proportional to the kinetic energy of the particles. The acoustic signals are converted by means of a transducer to corresponding electric signals which are processed by art computer means. Compensating probes are disclosed for subtracting extraneous noise.

Abstract: An image signal processing apparatus has a CCD for reading an image, a peak detector circuit for detecting a peak value of changes in an analog image signal received from the CCD, a slice level memory circuit for storing a fixed slice level, a comparator, and a slice level change circuit for setting a proper slice level for the image signal. Thickening of a character image or the like is prevented, allowing satisfactory readout of a microfilm image.

Abstract: A test manipulator externally applicable to a pipe, preferably for ultrasonically testing welded seams, the manipulator having a divided race for surrounding a pipe which is to be tested, a guide segment guiding the race at the periphery thereof, a test system carrier drivable in peripheral direction around the pipe, a driving and positioning device for the test system carrier and at least one test head holder fastenable to the test system carrier includes clamping means for fastening the race directly to the pipe in centered relationship to an adjustment mark located on the pipe; a guide segment mounted so as to be movable along the periphery of the race; an outrigger unit flangeable, together with the test system carrier and the test head holder, to the guide segment; and a saddle fastenable to the pipe in centered relationship to the adjustment mark; alternatively, during testing of a so-called pipe connection seam, the guide segment being movable on the saddle in axial direction of the pipe, and the race,

Abstract: A semiconductor vibration detecting structure formed on a semiconductor substrate and a method of manufacturing the same in which the curvature of the cantilever of the vibration detecting structure in the direction gradually deviating from the surface of the semiconductor substrate can be determined by the thickness of the upper nitride layer for regulating the curvature of the cantilever, with the thicknesses of the other layers constituting the cantilever and the length thereof being constant. In the semiconductor vibration detecting structure according to the present invention, even if vibrations having relatively large vibration levels are applied to the detecting structure, the cantilever of the vibration detecting structure vibrates well but never hits the surface of the semiconductor substrate, thus enabling a wide rage of mechanical vibrations to be detected with a high sensitivity.

Abstract: This seal is characterized in that the delay line is extended by a frustum-shaped part terminated by a spherical cap, which is able to receive a marking participating in the acoustic identity of the seal. The sealing capsule of the seal is perforated with an opening adapted to the dimensions of the frustum-shaped part of the identity module. The sealing cable is fixed between the module and the sealing capsule.Application to the monitoring of containers containing dangerous or precious products and the like.

Abstract: An electronic scanning apparatus ultrasonic imaging adapted to converge or deflect an ultrasonic beam by controlling the amplitude and phase of the vibration of each transducer in a transducer array consisting of a plurality of regularly-arranged transducers, and adapted to move the ultrasonic beam by selecting from all of the transducers constituting the transducer array at least one transducer forming a transmitting and receiving aperture.

Abstract: A process for modifying structural profiles produced by polymerization or depolymerization in resist layers. As a function of the acoustic impedance of the substrate carrying the resist layer, the structures are irradiated with an ultrasonic beam. An ultrasonic beam for which the substrate represents a high impedance is used in order to enhance the contrast of the structures. An ultrasonic beam for which the substrate represents a low impedance is used to weaken the contrast. An acoustic microscope is especially suitable for carrying out the process.

Abstract: Polar structures in microscopic object areas, such as, for example, electric or magnetic dipoles, can be locally selectively detected with high resolution if either resonant ultrasonic waves are induced in the object area by a locally effective high-frequency field and are detected by means of a focused acoustic lens arrangement, or electric or magnetic high-frequency oscillations are induced in the object area by focused ultrasonic waves and are detected by an appropriate receiver. By comparing the phases and/or amplitudes of the induced and of the detected waves, these provide information on the existence and the direction of the dipoles. Existing dipole alignments can be made energetically unstable by a critical direct-current electric or magnetic field and locally selectively reversed by the focused ultrasonic beam.

Abstract: The object of the invention is a method for the non-destructive testing of workpieces (14) or components with ultrasonics and a device for applying the method. The workpieces (14) are subjected in accordance with the through-transmission principle at the same locations (38) in succession with ultrasonic waves that differ by their opposing directions under conditions that are otherwise the same. The ultrasonic signals received in the two different sound directions are, provided they have different signal amplitudes, compared with given values obtained from a similar workpiece with defects in previously known depth in order to determine the depth of defect in the workpiece (14). If the sound absorption is complete, the ultrasonic waves continue to be applied in opposite directions to neighboring positions until ultrasonic signals are received whose differences are evaluated in order to determine the depth of the defect concerned.

Abstract: A method and an apparatus for inspecting a photomask pattern utilizing a vector comparing method. A pair of optical images intended to be compared are taken from the photomask pattern and converted to digital data by optical systems and an amplitude distributor. The digital data have values of black (B), gray (G), or white (W) corresponding to high, middle, and low signal amplitudes. Separated data corresponding to a portion of each of the optical images are sequentially separated from the digital data by data separators. The separated data are shifted by several matrix elements of the separated data by data shifters to provide shifted data. The shifted data of each optical image and separated data are respectively synthesized by data synthesizers to provide two groups of synthesized data. Vectors are generated from the matrices of the groups of synthesized data by vector generators.

Abstract: For selective detection of microscopic defects in a workpiece to be checked presenting at least one macroscopic discontinuity of known nature, upon relative motion in respect to such workpiece according to a given check line, detecting the times when such check line meets a discontinuity, and searching for any possible defects in the workpiece intermittently for time intervals defined in reference to said times. This applies in particular to inspection of weld seams of welded tubes.

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.