Abstract: The flow rate of a high temperature fluid flowing through a conduit is measured by passing ultrasonic waves through the fluid. The ultrasonic waves are emitted from an emitter located at one side of the conduit and are received by a receiver located at an opposite site thereof. A first spacer is disposed between the receiver and the conduit, and a second spacer is disposed between the emitter and the conduit. The spacers isolate the receiver and emitter from the high temperatures and conduct the ultrasonic waves without changing the frequency thereof. A quick-release clamp clamps the emitter, receiver and spacers together against the conduit.

Abstract: An apparatus for measuring a thickness of plate material includes a plate material whose thickness is to be measured, a vibration pen to generate a plate wave by applying a vibration to the plate material, a vibration sensor which is disposed at an arbitrary position on the plate material and detects the plate wave which has propagated on the plate material, an extracting circuit to extract different frequency components of the plate wave detected by the vibration sensor, a timer to measure arrival times to the vibration sensor of the signals of the different frequency components extracted by the extracting circuit, and a controller to obtain a thickness of the plate material on the basis of the arrival times measured by the timer and the frequency components corresponding thereto. The extracting circuit is a band pass filter.

Abstract: An ultrasonic transducer for measuring a property of a material within a defined space has a function of a velocity at which ultrasonic signals travel through the defined space includes a controller. The controller is adapted for coupling to a plurality of ultrasonic transducers. The controller include a multiplexer for selecting one of the plurality of ultrasonic transducers, signal processing means for processing an output of the selected ultrasonic transducer and controller means for providing parameters to the signal processing means based upon the selected ultrasonic transducer. The controller couples to a two wire 4-20 mA communication loop. The controller periodically excites the ultrasonic transducer to obtain a measurement. The controller stores power received from the two wire communication loop and excites the transducer using stored power. The controller is capable of providing power which exceeds that available directly from the two wire communication loop for a brief period of time.

Abstract: A transducer testing system for low frequency vibrations incorporates an electric motor/gearbox assembly 16 with an output shaft 18 and mechanical means for converting low frequency shaft rotation of the output shaft 18 to uniform low frequency sinusoidal excitation of an accelerometer 10. Simultaneously, a data processing unit 14 measures the response of the accelerometer 10 to the uniform low frequency excitation within predetermined frequency ranges. The data processing unit 14 then compares the measured response with predetermined accelerometer response limits to ascertain whether the accelerometer 10 is functional. The transducer testing system overcomes the limitations of electrodynamic testers to provide a means for accurately testing the low frequency response of the accelerometer 10.

Abstract: Apparatus and method for detecting the presence of ultrasonic wave energy at a selected location within a volume of material provides a visual display indicative of the ultrasonic wave energy at the selected location, and certain characteristics of the detected ultrasonic wave energy, by coupling with the volume of material, at the selected location, a column of ultrasonic wave energy responsive fluid medium with ultrasonic wave energy responsive visible particles suspended therein so as to induce corresponding ultrasonic wave energy in the column whereby the particles are suspended in the column and are arranged in a visible pattern to establish the visual display indicative of the ultrasonic wave energy at the selected location.

Abstract: A scanning tunneling microscope, in which the gap between a tip having a keenly sharpened end and a sample is narrowed to let flow a tunneling current between them and thereby allow observation of the surface of the sample, a strain wave detecting device is disposed on the sample or in the vicinity of the sample to detect strain waves generated within the sample. By modulating the value of the above described tunneling current, strain waves are generated within the sample. The strain waves are detected by the above described strain wave detecting device. On the basis of the amplitude information and phase information of detected strain waves, physical information regarding the inside of the sample is obtained.

Abstract: An ultrasonic flaw detection device including a transmitting ultrasonic transducer for producing multiple shear wave skips between inner and outer surfaces of a test object, a plurality of receiving transducers positioned ahead of and parallel to at generally the same incident angle as the transmitting ultrasonic transducer, and a processor electrically connected to the receiving transducers so as to produce a humanly perceivable indication of the reflected energy. The receiving transducers serve to receive energy of the shear wave as reflected from discontinuities in the object. Each of the receiving transducers is electronically isolated from the other receiving transducers. The receiving transducers are connected to a single channel of the processor. A fixture is provided having a first opening for detachably receiving the transmitting ultrasonic transducer and a plurality of receiving openers receiving the receiving transducers therein.

Abstract: Arrival of a pressure wave front is detected at a plurality of monitoring stations spaced along a protected section of a fluid-carrying pipeline. Arrival times obtained at the monitoring stations are qualified as to whether they correspond to a pressure transient event (critical event) which originated in the protected section. If so, the location, amplitude and time of occurrence of the critical event are determined. An uncertainty zone is derived at the extremes of the protected section having a length dependent on the precision of a time standard to which the monitoring stations are referenced and on the exactness of fluid velocity in the pipeline. An operator is so informed if the location of the critical event is determined to fall in the uncertainty zone. It is also possible to determine whether wave fronts correspond to an event occurring outside the protected section. Information from the resulting pass-through wave is used to update needed parameters useful for the critical event determinations.

Abstract: An infant hearing test apparatus, primarily intended for use in the early detection of hearing problems of human infants in the birth to eighteen month age group, subjects an infant under test to two low intensity test sounds of an electronically filtered human voice in the frequency range of about 2000 to 4000 Hz. Of particular utility are the higher frequency sounds that are associated with the voice of a human female, for example a mother speaking a language dependent endearing term such as "Hi Baby", and a language independent sound to which the infant is sensitive, such as the sound of an infant crying. Both of these sounds are used to test the infant for body movement, for example head movement, with both sounds being reproduced at a relatively low intensity of about 46 dB and at a distance of about 12 inches from the infant.

Abstract: Apparatus for determining, through an interposed medium, the mechanical properties of a solid comprised of more than one material, the solid having a surface.

Abstract: A vibrating sensor comprises an elongated element arranged to vibrate at a frequency dependent upon an external stress applied to the sensor, and an optical fiber for coupling light into an end of the element to excite it into vibration. A light-absorbing layer is provided on a longitudinal surface of the element such that the element will change its configuration, e.g. by bending, as the layer absorbs light and heats that side of the element, this alteration in configuration causing a reduction of radiation which is absorbed so that the element restores. The element may define a Fabry-Perot interferometer between its opposite ends.

Abstract: An ultrasonic measurement method for distinguishing between unflawed and flawed parts comprises the steps of detecting at least two prominent resonant response frequencies, measuring the frequency difference between the two frequencies, determining the ratio of the frequency difference to one of said frequencies, and comparing the ratio to a predetermined part criterion. Resonant response frequencies dependant upon physical characteristics such as dimensions and weight are compared to other resonances which are at frequencies dependant upon stiffness of the part.

Abstract: An ultrasonic probe is housed in a probe housing filled with fluid under controlled pressure. The probe provides ultrasonic sound through the fluid to a bladder which presses against the interior of a rotor wall. Located along the periphery of the bladder, a fluid wiper/soaker conduit provides droplets of fluid to the wall of the rotor bore to minimize friction between the bladder and the rotor bore wall and provide an ultrasonic path between the bladder and the rotor wall.

Abstract: A signal enhancement system for separating a composite diagnostic signal detected in a rotating machine into component signals representative of the contributions to the composite signal of a number of independent sources. The signal enhancement system includes at least one signal subtraction loop having a transducer which produces a reference signal based on the rotational speed of a rotating shaft in the machine and an adaptive filter connected to the transducer. The adaptive filter processes the reference signal to produce a component signal which closely approximates the contribution of the rotating shaft to the composite signal. A summer is also included which subtracts the component signal from the composite diagnostic signal to produce a second component signal. Both the first and second component signals are provided as outputs of the system.

Abstract: A monitoring diagnostic apparatus for detecting an abnormality occurring in an object being monitored such as electrical equipment and determining the cause of the abnormality is disclosed. First of all, vibration or partial discharge occurring in the monitored object is detected by using a sensor installed in close proximity to the monitored object. A detection signal output by the sensor then undergoes predetermined signal processing such as the Fourier transform and normalization. After the predetermined signal processing is completed, a neural network identifies the abnormality occurring in the monitored object and determining the cause of the abnormality. The neural network carries out a learning process based on causes of abnormalities occurring in the monitored object, outputting signals corresponding to the causes of the abnormalities.

Abstract: An ultrasonic detecting apparatus which includes a sequence generating means and a transmission signal generating means for generating a transmission signal corresponding to the sequence. The detecting apparatus also includes a transmitting means to transmit waves, which may be ultrasonic waves, to an object and a receiving means for receiving an echo corresponding to the transmission signal. A correlation operation means performs a correlation operation with respect to the echo. In another general aspect, the sequence generating means may generate more than one sequence, some of whose auto-correlation functions produce substantially zero sidelobe in the summed result. In a further general aspect, the sequence generating means generates two or more sequences, with each of the sequences being different from the others and having substantially the same auto-correlation function as the others.

Abstract: Two geophones located above an underground pipeline are spaced from each other and adjacent to both sides of a benchmark location. As a pig travels through the pipeline sound waves are generated. As a pig approaches a benchmark location, sound waves are received first by the geophone which is closest to the source of the sound waves, that is, the upstream geophone and then by the downstream geophone. The geophones generate electrical signals that are fed to a comparator circuit which is connected to upstream and downstream indicators, one of which is activated when a pig passes the benchmark depending on whether the sound was first received by the upstream or downstream geophone. An alternate embodiment adds a magnetometer at the benchmark location capable of sensing changes in the ambient magnetic field caused by the passage of a pig.

Abstract: An ultrasonic detecting apparatus which includes a generator which generates more than three transmission signals. The detecting apparatus also includes a transmitter/receiver which transmits waves, which may be ultrasonic waves, to an object and receives echoes corresponding to the transmission signal. A correlator performs correlation operations with respect to the echoes. The results of the correlation operations are processed to obtain a signal with substantially zero side lobes.

Abstract: A method and apparatus for determining the setting time of a cement slurry. An acoustic shear wave signal is generated and introduced at a first location in the slurry. The signal is monitored at a second location for direct transmission of the shear wave signal. The time of first detection is determined at the second location which is taken as the setting time of the slurry.

Abstract: A shaker table (10) for testing and quality control of devices attached to the table is shown. The mounting table has pneumatic exciters (50) attached thereto. The mounting table (20) provides uniform distribution of forces applied by the pneumatic exciters (50). The forces are evenly distributed in all directions from the impact of the exciters on the mounting table. The mounting table (20) is supported on a foundation (2) by adjustable supports (4). The exciters are supplied with pressurized air from a source (12) through an airline (14).