Abstract: An ultrasonic microscope is provided wherein a sample placed in a medium is irradiated with a focused ultrasonic wave from a focusing ultrasonic transmitting element and the focused ultrasonic wave is detected by a focusing ultrasonic receiving element. The sample (or the focusing transmitting element and the focusing ultrasonic receiving element) is moved within the X-Y plane, and either the focusing transmitting element or the focusing ultrasonic receiving element is vibrated toward the sample along the beam axis.

Abstract: The invention relates to a method of ultrasonic measurement of the ratio of the volume of gas present in an enclosure containing a diphase liquid-gas mixture to the volume of the enclosure, or void coefficient. Waves at different frequencies are propagated through the fluid filling the enclosure (1). The propagation times of the waves are measured and the difference between these propagation times is calculated. If the propagation times are identical, it is deduced that all the gas is in the form of a layer surmounting the liquid. The void coefficient is determined from the propagation velocities of the ultrasounds in the gas and the liquid and from the measured propagation time. If the propagation times are different, a part of the gas is in the form of bubbles in the liquid, the void coefficient due to the gas surmounting the liquid and the void coefficient due to the gas bubbles in the liquid are determined separately. The total void coefficient is determined by adding the two values obtained.

Abstract: Materials and structural components having irregular shapes may be tested two ultrasonic testing heads which are movable in unison in the direction in which the cross-section of the material or component being tested changes. The synchroneously moving testing heads are spaced from each other in a direction extending across the moving direction. The testing heads are ultrasonic receivers connected with their outputs to a comparing device which provides an error signal when the amplitude ratio of the received signal changes. The amplitude ratio is formed between the amplitudes of the ultrasonic signals received by both testing heads. Preferably, the comparing device comprises an amplifier which amplifies the amplitude of the received second signal by an amplification factor which is proportional to a deviation of the amplitude of the received first signal from a reference value. The error signal is recorded, for example, by a coordinate plotter.

Abstract: Methods and apparatus for determining density of gases and vapors. The primary sensing device is a fluidic oscillator through which a sample of gas is passed.

Abstract: Methods for determining the amount of a gas adsorbed or desorbed from a solid sample wherein a gas is introduced or withdrawn from a sample containing chamber at a substantially constant mass flow rate while measuring the pressure change within said chamber as a function of time is disclosed. An apparatus for conducting said method which uses a mass flow controller is also disclosed.

Abstract: A computerized audiometer is provided with at least one head set, a control switch, a tone generator for providing a plurality of sequential tones of different frequencies and amplifications to at least one head set, and a central processing unit for receiving data representative of the response to the test of the person being tested as reflected by the operation of the control switch. The central processing unit is adapted to analyze the test data and produce a program representative of the correction required by the person being tested. The audiometer is provided with a programming output adapted for coupling to a hearing aid for programming a hearing aid by applying the program developed by the central processing unit to the hearing aid.

Abstract: An ultrasonic system for non-destructive testing in industry and for visualizing soft tissue structure in medical diagnosis using a coaxial transducer array formed of a plurality of annular transducer elements each having the same predetermined area. The area of each of the transducer elements and the radiating aperture of the array is chosen to provide a well-resolved narrow beam in accordance with the focal length along the axis of the array.

Abstract: A method for projecting the landfill gas collection rate of a surface collector, including removing some of the cover material from the landfill to expose a test area of the refuse in the landfill and measuring the venting rate of the landfill gas through the test area under essentially steady state pressure conditions in the landfill. Additional cover material is then removed to enlarge the test area and the measuring step is repeated. The measured venting rates are used for projecting the approximate collection rate for a surface collector.

Abstract: Apparatus for detecting acoustic emissions from metal matrix wire allows on-line measurement of the transverse strength of the wire as it is moving through its manufacturing process. A series of end and middle rollers guide the wire and form a bend in it. The location of the bend in the wire is maintained in contact with a liquid bath which, in turn, is contacted by the sensing surface of an acoustic transducer. Acoustic emissions from breaking of the fiber-matrix interface of the wire are transmitted by the bath and detected by the transducer.

Abstract: A portable gas analyzer uses a pump to take a gas sample and pump it through a carbon monoxide sensing cell, an oxygen-sensing cell and a methane-sensing pellister. Concentrations of these gases are displayed continuously on LCD displays. The gas analyzer is particularly useful in underground coal mines and offers the possibility of replacing many different gas analyzers with a simple convenient apparatus which gives continuous readings of all the critical gas concentrations.

Abstract: An enclosure (17) contains two ovens (18, 19) each containing a semiconductor metal oxide (SnO.sub.2 or NiO) sensor (13) previously activated using H.sub.2 S or SO.sub.2. The sensors (13) are heated to different temperatures the lower of which corresponds to a peak on the sensor conductivity curve characteristic of the gas. The signals produced are applied to a comparator (30). For many toxic gases this peak occurs at concentrations below their toxicity threshold in air.

Abstract: A probe (P) capable of sensing acoustic and hydrodynamic pressures in a heated flow field and an associated apparatus for acoustically exciting the heat flow (35), for positioning the probe (P) within the flow field and fro acquiring data. The probe (P) consists of a miniature microphone (10) mounted in an assembly which provides direct water cooling to the microphone body and which, by means of a bullet nosed extension (23, 24) with lateral ports (25), protects the microphone element (10) from direct impingement of the flow (35). Acoustic excitation of the flow (35) is introduced upstream of the nozzle (34) through a tube (37) from an externally mounted acoustic driver (36) which responds to the amplified output of a signal generator (38); the signal generator (38) and the amplifier (39) are adjusted to control the frequency and amplitude of the excitation. A traversing mechanism (32), capable of movement in three orthogonal directions is used to position the probe (P) within the flow (35).

Abstract: A system for measuring from the outside of a living body the pressure within the heart or the pressure of any portion which does not allow a measurement by the direct insertion of a pressure measuring sensor.This system provides a method of measuring the pressure of the object by generating fine bubbles through cavitation, applying a low frequency ultrasonic wave to the medium, and then detecting the bubbles which are generated with a system for detecting the high or low frequency harmonics due to the bubbles or a higher frequency ultrasonic wave applied to the medium.

Abstract: A process for monitoring the presence of cracks, formation of cracks and growth of cracks in constructions, for example off-shore oil and gas platforms, by recording and analysis of acoustic emissions from the construction, the sensors being mounted in the medium which surrounds the construction instead of on or in the construction itself.

Abstract: Calibration of sensors of the type used for the cutaneous determination of blood oxygen and carbon dioxide levels is facilitated by providing separate sensor units, alternatively and removably connectable to a calibration device and to the measuring devices with which they are used for such determinations. The sensor units contain, in addition to a sensor electrode, a data memory in which is stored calibration data generated when the sensor unit is connected to the calibration device. The calibration device can provide a plurality of calibration stations, each capable of supplying a standard gas to a connected sensor and, in response to signals from the sensor exposed to the standard gas, generating data signals representing the calibration of the sensor, which signals are transmitted to the data memory of the sensor unit. Upon connection of the sensor unit to the measuring device, the calibration data from the data memory of the sensor unit are used as a calibration base for measurements by the sensor.

Abstract: There is disclosed an acoustic inspection method for determining whether the actual fluid flow path through a manufactured fluid flow system such as an evaporator core is of a prescribed length and thereby free of such manufacturing errors as cause a shortened or lengthened fluid flow path. The method comprises the steps of passing a test sound wave of predetermined frequency along the actual fluid flow path through the manufactured fluid flow system and comparing the phase angle of the test sound wave at the exit of the actual fluid flow path being inspected with that of a reference sound wave of the same frequency passing along the exactly prescribed fluid flow path length and on the basis that a difference in phase angle indicates that the fluid flow path being inspected is not of the prescribed length.

Abstract: Apparatus for and method of open-tube supercritical fluid chromatography.

Abstract: A gas composition sensor includes a gas sensor element having an electric resistance value which varies in accordance with the composition of exhaust gases to be sensed, and a pair of electrodes attached to the gas sensor element for detecting the electric resistance value, whereby the resistance value of the gas sensor element is detected to sense the composition of the exhaust gases. A layer of material substantially impervious to the gases is formed on the gas sensor element to extend between the electrodes and surround the electrodes and the layer is also formed on other portions of the electrodes exposed to the exhaust gases.

Abstract: An ultrasound tomography device for scanning an object under examination from a plurality of directions. Coronal slice images of the plane areas near or at the female breast wall are obtained. Ultrasound lobes from ultrasound transducers are electronically directed or mechanically positioned to obliquely strike the coronal slice located at or near the breast wall. A full image of the coronal slice plane is reconstructed through section by section combination of the images obtained from the several ultrasound lobes.

Abstract: An ultrasound tomography device for scanning an object under examination from a plurality of directions. Coronal slice images of the plane or planes near or at the female breast wall are obtained. A sagittal scanner is used to obtain numerous small sectional oblique views of the slice to be viewed. A full image of the coronal slice plane is reconstructed through section by section combination of the images obtained from the several small sagittal sections. By providing the sagittal scanner with a scanning motion as well as with translational mobility a full composite view is provided.