Abstract: Apparatus for detecting failure of a surface tension screen disposed between a holding chamber and a main chamber of a tank includes a fixture for supporting the tank in desired test orientations, a drive mechanism on the fixture for rotating the tank and an ultrasonic transducer used in making a measurement with respect to the position of an interface between liquid and gas contained in the holding chamber of the tank. The holding and main chambers are tandemly arranged along a longitudinal axis of the tank and are each substantially filled by a liquid propellant with respective volumes of gas contained in each chamber. The fixture supports the tank in a first orientation with a nose of the tank pointing downwardly and tank longitudinal axis extending approximately 60.degree. above horizontal and to the right of vertical and in a second orientation with the tank nose pointing upwardly and tank longitudinal axis extending approximately 60.degree. above horizontal and to the left of vertical.

Abstract: An ultrasonic method and apparatus are described for determining the depth of cracks 12 in a pipe or conduit 14. The apparatus 10 includes a transmitting transducer 30 and a receiving transducer 40 that are placed on the outside surface of the pipe to one side of the pipe. The transmit transducer 30 is energized to direct a shear wave beam 34 of ultrasonic energy at the crack to generate a complex reflected wave front from the crack 12 which contains information as to the size of the crack in relation to the wall thickness. The recovery transducer 40 is moved relative to the transmit transducer until a peak or maximum amplitude reading is found. When the maximum amplitude is found, the distance between the transducers is measured. The measured distance is then correlated with information obtained from specimens 80 of the same material and wall thickness as the on-site pipe to determine the depth of the crack 12.

Abstract: According to the process signals adapted to the medium and to the kind of discontinuity to be analyzed are transmitted towards the discontinuity from a number of transmitting points located on at lease one base line, these signals are received at a number of reception points located on at least one base line placed on the opposite side of the discontinuity as far as the transmission paths are concerned; the received signals are then analyzed to obtain the position and shape of the discontinuity. In certain cases the echos and backscatter are also analyzed. At least one of the base lines F.sub.1 carrying the transmission points does not intersect with at least one of the other base lines carrying the reception points. This system and method may be used to determine the position and shape of underground discontinuities, to analyze the internal structure of human or animal bodies, or any other inanimate object in any medium.

Abstract: Herein disclosed is a method for ultrasonic flaw detection of T-welded portion of steel product. The method comprises: maintaining the flange portion horizontally, making convergent ultrasonic beams incident on the flange portion vertically to the top face of the flange portion through a medium, scanning the incident beams transversely of the welded portion, detecting ultrasonic echo from a depth corresponding to the bottom face thickness of the flange portion, and comparing the level of said ultrasonic echo with a predetermined threshold value. Disclosed also is an apparatus for carry out the above method. These method and apparatus are suited particularly to the on-line flaw detection of the welded shape steel.

Abstract: In ultrasonic flaw inspection for determining the size of a flaw by emitting an ultrasonic wave to a subject via a probe and receiving an ultrasonic echo from said flaw existing inside said subject, changes in the propagation distances of the ultrasonic echoes before and after movement of said probe through a micro-small distance are compared with each other and the ultrasonic echoes are determined to result from the same flaw if the change width falls within a predetermined value determined by the angle of incidence of the ultrasonic wave and the directional angle.

Abstract: A method of testing the integrity of the internal lining of a hollow body, especially a pipeline, by transmitting an ultrasonic wave from the exterior of the body through the adjacent wall of the body and monitoring the wave, if any, reflected from the opposite wall. In many cases, especially concrete linings, an intact or partially intact lining on the adjacent wall will absorb the ultrasonic wave and there is no reflected wave. A reflected wave frequently indicates loss of the lining on the adjacent wall although in some cases depending on, for example, the thickness of the lining or the material of which it is made, a reflected wave may be obtained even when the lining is intact. In such cases comparison of the reflected wave with predetermined standards provides an indication of whether or not the lining is intact.

Abstract: Method and apparatus for measuring an attenuation characteristic in a region of interest using ultrasound wherein two statistically independent set of values are accumulated as a difference between logarithms of pairs of each signal set, and the attenuation characteristic calculated as a central tendency parameter of each set of values.

Abstract: A machine for grinding toothed cutting tools comprises an emitter capable of emitting a light or an ultrasound ray and an optoelectronic or an ultrasound receiver respectively. The receiver is associated with a circuit for controlling the movement of a table of the machine on which a tool to be ground is supported. The positioning of the table is effected by the interception of the light or sound ray by the teeth of the tool, which causes the receiver to act to stop movement of the table.

Abstract: Sheet or plate stock is used as to defects by a row of ultrasonic transmitting transducers on one side and receiving transducers on the other. The transmitting transducers receive frequency-modulated signals via individual buffers, and the receiving transducers feed individual, digital amplitude envelope minima to detection circuits whose outputs are fed to a computer which also feeds operating parameters to the source for the modulated signals. Different types (autonomy) of the receiver channels are described as well as diagnostic and setup procedures.

Abstract: For testing wooden poles, a transmitter unit including a piezo electric transducer, energized to produce repetitive pulses of ultrasonic frequency, is held against the pole. The transmitter unit produces an audible sound synchronously with each ultrasonic pulse. A portable receiver unit having a probe coupled to a piezo electric transducer is held against the pole. This receiver unit includes a signal level comparator which causes a lamp to flash on for each received ultrasonic pulse above a predetermined amplitude. The receiver is held in a plurality of positions and readings are noted where the lamp flashes synchronously with the audible signal. From these readings the strength remaining in the pole to resist bending forces is calculated.

Abstract: An ultrasonic, non-destructive inspection system for detecting separations and/or holes in vehicle tires. The system employs a through transmission method at ultrasonic inspection in which the ultrasonic transmitter array and the ultrasonic receiver array are both mounted in air and in a non-contacting, non-critical relationship with the tire undergoing inspection. The inspection is performed in one revolution of the tire.The ultrasonic transmitters are pulsed and the receivers are sampled during predetermined time intervals which are related to the transmitter/receiver/tire geometry. This eliminates the problems of talk-around and standing waves. The problem of transmitter--transmitter interference is eliminated by transmitter frequency separation and transmitter array pointing geometry. The problem wherein tread pattern fluctuations in the received signal interfere with flaw detection is eliminated by the use of a finite sampled data filter whose period is adjusted to the period of the tread pattern.

Abstract: A pulsed through-transmission ultrasonic non-destructive inspection of the internal structure in a tire wall is effected. The ultrasonic inspection is preferably carried out through the walls of a rotating inflated tire with the ultrasonic transducers being automatically moved toward the inner and outer tire wall surfaces to optimum relative distances of separation during an inspection cycle. The transducers disposed inside the inflated tire are preferably mounted for automatic retraction into a protected space during tire mounting and demounting operations. Such ultrasonic inspection techniques may be combined with conventional tire buffing methods and apparatus as practiced in tire retreading operations.

Abstract: A pulsed through-transmission ultrasonic non-destructive inspection of the internal structure in a tire wall is effected. The transmitted acoustic signals preferably have a frequency of least 40 Khz, are transduced to electrical form, amplified with a relatively long time constant AGC, rectified and integrated during only the initial or leading edge portions of each pulse or burst. The resulting integrated analog signal values thus provided have relative magnitudes which may be displayed or otherwise processed to detect structural anomalies within the tire wall. If plural acoustic transmitters are utilized, they are preferably multiplexed such that only a single transducer is activated at a given time.The ultrasonic inspection is preferably carried out through the walls of a rotating inflated tire with the ultrasonic transducers being automatically moved toward the inner and outer tire wall surfaces to optimum relative distances of separation during an inspection cycle.

Abstract: A pulsed through-transmission ultrasonic non-destructive inspection of the internal structure in a tire wall is effected. The transmitted acoustic signals preferably have a frequency of least 40 Khz, are transduced to electrical form, amplified with a relatively long time constant AGC, rectified and integrated during only the initial or leading edge portions of each pulse or burst. The resulting integrated analog signal values thus provided have relative magnitudes which may be displayed or otherwise processed to detect structural anomalies within the tire wall. If plural acoustic transmitters are utilized, they are preferably multiplexed such that only a single transducer is activated at a given time.

Abstract: Disclosed is a nondestructive test method for inspecting an object, including the steps of generating a surface acoustic wave at a first location on the object, detecting a harmonic of the generated wave at a second location on the object, and relating the characteristics of the detected wave to the remaining useful life of the object. The amplitude of the detected harmonic may be compared to standard amplitude values to predict the percentage of fatigue life remaining in the object, or the amplitude may be used to estimate the size and density of cracks in the object. Additionally, the harmonic wave may be detected for a range of stress values, the amplitude differential between the maximum harmonic amplitude and the minimum amplitude under compression calculated, and the differential related to the remaining useful life of the object.

Abstract: Disclosed is a method for evaluating a discontinuity in an object. As used to measure the depth of a surface discontinuity in a plate type of object, the method includes the steps of generating a horizontally polarized shear wave in the object directed substantially along the axis of the discontinuity, passing the generated wave through an aperture to diffract the wave prior to its arrival at the discontinuity, detecting the wave after it has propagated through the discontinuity, and calculating the depth of the discontinuity by correlating the phase and amplitude of the detected wave to the phase and amplitude of a similar wave propagated in a region of the object which is free of discontinuities.