Abstract: An engine timing apparatus includes a piezoelectric transducer and a device for mechanically coupling it to a fuel injector body of the engine. A 6-inch clamping-type pliers is clamped to the injector body. A metal housing is fastened to the pliers at the jaw pivot, the housing having a cylindrical side wall and a circular bottom wall in positive contact with the pliers. The transducer is supported in a recess in a rubber sleeve in the housing and cooperates with the housing to define a resonant chamber at substantially 40 Khz. The dimensions of the pliers are such that the ultrasonic acoustic emissions of the injector body induce in the pliers a standing wave at substantially 40 Khz or a harmonic thereof, the jaw pivot being disposed substantially at an antinode, or point of maximum displacement, of the standing wave. The housing above the transducer is filled with an acoustically insulating foam and covered with a plastic cap.

Abstract: A method and device for detecting a narrow acoustic spectral feature in a sample as described. The method uses an electrical frequency modulated (FM) signal that is obtained from a voltage controlled oscillator. The Fourier spectrum of this wave is a main frequency f.sub.c with two small sidebands at frequencies f.sub.c .+-.f.sub.s. This whole triplet is slowly swept in frequency by a slow sawtooth generator. The electrical signal is fed into a flat acoustic transducer; the acoustic wave is then transmitted through an acoustically active medium, i.e. the sample, and detected by another flat acoustic transducer which produces an FM signal with a superposed amplitude modulated (AM) signal if one of the sidebands overlaps an acoustic feature. This electrical signal is then demodulated to give a pure AM signal which can be phase sensitive detected by using a lock-in amplifier.

Abstract: The present invention utilizes a wire wool slug packed inside a helical coil of an aircraft engine sensor in order to reduce vibration damage to the coil.

Abstract: The properties of the surface layer of a material are measured by a technique which employs the transmission of ultrasonic waves from varying angles of incidence into a specimen, from a transducer at a point spaced from the specimen. The backscattered waves are detected and evaluated from the varying angles to detect the local maximum intensity, from which the corresponding properties of the material are determined.

Abstract: An apparatus for detecting damage to the cutting tool fitted in a machine tool controlled by automatic machining control circuit means such as a microprocessor, which acts to sense the level of acoustic emission generated by the machine tool during machining, compares that level with one of a plurality of different predetermined data values which are stored in a memory circuit, and generates a warning signal if the noise level exceeds the predetermined level. The different data values stored in the memory circuit are respectively utilized for different machining conditions, i.e. different combinations of cutting tool, machining material, feed rate, etc.

Abstract: There is described a system for producing noise particularly for sonic testing of an article, such as a satellite, in a reverberation chamber. In one of its aspects the system comprises a low frequency high-level broad-band noise source; a tube means including a section formed as an acoustic horn connected at its small end to the low frequency source and at its large end to the chamber. A Hartmann-type air acoustic high level noise generator, or generators are located inside the tube at a predetermined position. In operation the generator is excited by the generated low frequency noise to provide an output of non-linearly modulated noise. Also described is a Hartmann-type noise generator which comprises a nozzle and an aligned acoustic tube spaced therefrom by an air gap. A reverberation cup is formed in the mouth of the tube facing the nozzle and a bridge member extends between the nozzle and tube and spans the air gap.

Abstract: An ultrasonic echo sounding device permits observation of the web formation and/or the pulp suspension flow on the wire part and in the head box of a paper machine. The device includes a series of ultrasonic detectors connected to the wall of the flow channel in the head box and/or to the forming wire. The detectors direct an ultrasonic field at the pulp suspension layer, and the echo signals received from the pulp suspension layer are detected. The detectors operate as acoustic lenses so that the focal points thereof are located in the transverse direction of the pulp suspension flow and in the direction of thickness of the pulp suspension layer in a manner whereby information concerning fibre bundles, air bubbles, variations in consistency, corresponding parameters and their variations in the transverse direction of the pulp suspension flow and in the direction of thickness of the pulp suspension layer are indicated by the device.

Abstract: A zero crossing detection circuit for estimating the ultrasonic attenuation in a region of interest in the body from an A-line signal which is representative of pulses of ultrasound energy reflected from said region. The ultrasound attenuation is estimated from the center frequency f.sub.Z of the returned energy which is calculated from the formula: ##EQU1## as measured at various depths in the body.

Abstract: A plurality of sensors are disposed equally about a blade row in a turbine with each sensor being operable to provide an output signal in response to a passing blade. A blade is selected for monitoring purposes by designating its degree location relative to a reference position .+-. some angular distance constituting a small window. As the selected blade passes a sensor, its output signal, properly conditioned to form a pulse, is gated during the time period corresponding to the window. The sequential pulses of the sensors form a pulse train which is modulated by any blade vibration. An FM detector is provided for demodulating the pulse train to derive vibration information.

Abstract: For use with a cement supply, cement pump and a cement delivery system for cementing a well, an indicator including a real time display system is set forth in the preferred and illustrated embodiment. By means of surface measurements obtained at the manifold connecting to the wellhead, a display of the flow of various fluids pumped down hole is obtained. In addition, the device provides real time plotting of bottom hole pressure, hydraulic horsepower and actual hydrostatic gradients. This and other data are displayed along with a mock-up of the piping system at the wellhead, the tubing string in the well and the annular flow path.

Abstract: Method and apparatus are provided for determining the formation pressure. The magnitude of formation pressure may be derived as a function of changes in bottomhole pressure following swabbing the borehole to draw formation fluids into the borehole, monitoring the borehole for influx of formation fluids, determining the reduced pressure due to swabbing, repeating the swabbing and monitoring steps until an influx of formation fluids is detected thereby determining the pressure of the formation.

Abstract: An ultrasonic thickness gauge circuit includes a dual transducer probe and a logic circuit for providing square wave signals whose duration is equal to the time interval between the ultrasonic signal entering a workpiece to be measured and the reception of the ultrasonic signal reflected at the rear surface of the workpiece. When measuring thin wall thicknesses a measuring error arises due to the "V"-shaped transit path of the ultrasonic signals being greater than twice the wall thickness of the workpiece. A low-pass filter and a comparator are provided for modifying the square wave signals to effect correction. The modified signal is then used for providing clock pulses, the quantity of which is a measure of the wall thickness of the workpiece.

Abstract: A system for the examination of a test object for internal flaws (or acoustic discontinuities such as solid-to-gas or solid-to-liquid interfaces) by means of ultrasonic waves. The ultrasonic waves 18 are induced in the object 16 by projecting at least one intense, pulsed laser beam 13 on the object 16 and scanning the beam 18 along the object 16. Another laser beam 23 is projected on the object 16, either opposite the first beam 14 or on the same side adjacent to the first beam 14, so that is reacts with and is frequency-modulated by the ultrasonic wave. The reflected, frequency-modulated beam 24 is fed to an optical heterodyning means 26 which passes through only an optical beam 28 modulated with the ultrasonic frequency to a photodetector 30.

Abstract: A transducer rendered operative by a battery voltage source is mounted on and closely spaced from a sonic radiating surface by a sonic coupling body to which a housing is secured in enclosing relation to both the transducer and the battery source. Openings in the housing expose a volume control knob and an output signal jack through which a signal cable connects the transducer to a remotely located amplifier.

Abstract: A non-destructive method and apparatus for inspecting materials in excess of 500.degree. C. includes a dual transducer disposed upon a delay line suitable for operation at the elevated temperatures. The delay line is divided into two parts acoustically isolated and is cooled by a fluid to maintain the surface upon which the transducers are mounted at a safe operating temperature.

Abstract: A distance-determining detector and method. A piezoelectric ultrasonic transceiver sends out pulses and receives their reflection and produces an analog output and a trigger output. The analog output is given effect only when it exceeds a threshold level, as shown by a comparator. The trigger output is used for disabling detection during transmission of the transmitter pulse and for producing a time interval during which the analog output is valid, when enabled. An AND gate is connected to the comparator and to the enabled trigger output. Clock pulses are counted, and a flip-flop circuit is connected to the counter and to the output from the AND gate. A multiplying digital-to-analog converter is connected to the flip-flop circuit for determining the distance. There may also be temperature compensation and scaling for the converter for validating the output thereof over a wide range of temperatures.

Abstract: An improved system for containment and detection of leakage of petroleum products from subterranean tanks or lines is disclosed wherein the tanks or lines are provided with a leak sensing means positioned adjacent the tank, and the tank or line together with the leak sensor is enclosed in an impervious enclosure which is sealed about the tank or line to prevent actuation of the leak sensor except due to leakage from the tank. In a preferred form the leak sensor is housed in a perforated duct which extends through and is sealed within the enclosure permitting access to the leak sensor and the interior of the bag in the event that a leak is detected. A preferred material for use in making the enclosure is welded high density polyethylene (HDPE).

Abstract: A method and apparatus for detecting disbond in laminar workpieces. Energy is transmitted to a workpiece (8) by repetitive impacts. A transducer (12) converts energy emitted from the workpiece (8) to an electrical signal. The energy emitted in response to each of the repetitive impacts is analyzed. After filtering out the DC component (20) and amplifying the signal (30) the maximum amplitude of the energy from each impact is selected (50) and passed to a sample and hold circuit (60). The piecewise linear output of the sample and hold circuit (60) is passed through a low pass active filter (70) prior to recording on a strip chart recorder. The strip chart record is analyzed to ascertain areas of the workpiece (8) having defective clad bonding (7).

Abstract: A wheel probe for ultrasonically inspecting a component, such as the wall of a pipeline, is of hollow form to define a chamber in which an ultrasonic transducer is located. The transducer is supported by a mounting which occupies a major proportion of the chamber and comprises material for attenuating background noise in the wheel probe. The chamber is closed by an end member which also comprises material for attenuating background noise, while an elastomeric tire on the rim of the wheel probe extends over a portion of reduced diameter of the rim to attenuate unwanted ultrasound.

Abstract: A focusing ultrasonic transducer element comprising an ultrasonic propagating medium and an ultrasonic transmitting and receiving transducer. The ultrasonic propagating medium is provided with a convex spherical or cylindrical portion in one end and a concave spherical or cylindrical portion in the other end.