Abstract: A therapeutic hyperthermia system generates a line-focus beam of ultrasound which can be mechanically scanned across a treatment volume of tissue. The ultilization of a line-focus advantageously reduces the peak intensity of the ultrasonic beam. The system includes methods of scanning the line-focus beam to provide optimal treatment protocols for deep tumors and other pathological conditions while minimizing damage in overlying body tissues. The utilization of mechanical scanning reduces the number of transducers, amplifiers and associated electronics required.

Abstract: A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

Abstract: The vapor pressure of a multi-component liquid composition is measured by providing an eductor through which the liquid composition is caused to flow at selected inlet pressures to provide incrementally changing pressure differentials across the eductor. The pressure differential is read for each incremental change across the eductor and the suction port pressure is read at each incremental pressure differential until the suction port pressure as a function of the pressure differential indicates a change in slope or point of inflection along the so-called dead fluid curve indicating the bubble point or true vapor pressure of the liquid composition. A motorized pressure regulator valve may be interposed in the liquid composition flow conduit upstream of the eductor for incrementally changing the pressure differential.

Abstract: Method for measuring vapor pressure of liquids in which liquid to be measured is placed in a previously-evacuated measuring cell, and influence of the gas dissolved in the liquid on the measuring results is eliminated. The liquid to be measured is added in at least two separate portions, with total pressure present in the measuring cell being measured after the addition of each portion and after saturation vapor pressure equilibrium has become established, to obtain a thus-measured value. Gas pressure present in the measuring cell which is due to the gas dissolved in the liquid is derived from at least two thus-measured values which had been obtained at the same measuring temperature in which pressure components due to vapor pressure of the liquid are equal, taking into account the liquid quantity contained in the particular liquid portions and the measuring cell volume with the relation po=RT.

Abstract: Apparatus and methods for determining the Reid Vapor Pressure of a bottoms product stream of a fractionating column used for fractionating a multi-component hydrocarbon feed stream into an overhead product stream and a bottoms product stream are provided. The Reid Vapor Pressure of the bottoms product stream is determined in response to the temperature of the bottoms product stream, the vapor pressure of the bottoms product stream, the rate of flow of the bottoms product stream and the rate of flow of the overhead product stream, without an analysis of the particular product stream. The Reid Vapor Pressure indication is used to maintain the actual Reid Vapor Pressure of the bottoms product system substantially equal to the desired Reid Vapor Pressure of the bottoms product stream and to thereby control the quality of the bottoms and other product streams.

Abstract: An ultrasonic probe having a vibrator which generates and receives ultrasonic waves is disclosed. The probe includes a first acoustic lens layer provided on the emergent/incident surface of the probe and a second acoustic lens layer provided on the first acoustic lens layer, the second acoustic lens layer having an attenuation constant which is different from that of the first acoustic lens layer. Accordingly, it is possible to make uniform the ultrasonic attenuation factor at various points of the acoustic lens while minimizing the attenuation factor at each of the points. Thus, it is possible to focus acoustic beams and hence obtain a clear ultrasonic image.

Abstract: An ultrasonic probe 1 for non-destructive material testing of slotted or hollowed pieces of material 2 and comprising a carrier 3 and a probe part 4 connected to said carrier, which probe part is formed with one or several piezo-electric crystals 5 provided at or adjacent the tip thereof and mounted at an angle to the longitudinal plane of the probe of between 45.degree. and 50.degree. and rotated around its own axis over an angle of about 45.degree.-47.degree.. The probe can be formed with two or several symmetrically arranged piezo-electric crystals for allowing a complete testing of the piece of material by one single docking operation in that the different crystals are connected in turn after each other. Further the probe may also be formed with one or several straight scanning piezo-electric crystals 6 mounted in the carrier 3.

Abstract: Ultrasonic flow meter of the clamp-on type for the measurement of the flow rate of a liquid in a pipeline, provided with two piezoelectric transmitting-receiving transducers, each accommodated in a housing, which are clamped at both sides of the pipeline axially offset with respect to each other thereon and which alternately transmit ultrasonic pulses into the pipeline and receive them therefrom in order to determine the flow rate from the transit time of the source pulses in the upstream and downstream direction. The transducers each consist of a row of adjacent subtransducers, the pulse emission face of which row is coupled over its entire length in the axial direction to the pipe wall.

Abstract: An acoustic transducer array includes a number of transparent continuous aperture transducer elements which are aimed at various angular sectors in a field of view and are embedded in an acoustically transparent material such as casting resin. Each transducer provides a beamformed output, and the transparency of the elements ensures that each element observes an acoustic field that is unperturbed by the other elements. A high resolution and a wide field of view are obtained by overlapping the transducer elements so that each element captures an increased area of acoustic signal. Preferably, the transducer elements are cut from thin, flexible metalized sheets of voided piezeoelectric polymer such as polyvinylidene fluoride or polyvinyl fluoride co-polymer. The polymer transducers are broad band in nature, and permit multiple frequency, multiple beam sonar configurations.

Abstract: A transmitter- receiver of an ultrasonic distance measuring device comprising a cylindrical piezoelectric element made of a polymer in place of a piezoelectric vibrator of a ceramic material or the like which has heretofore been used. The cylindrical piezoelectric element is secured to a columnar supporter in such a manner as to define a chamber in cooperation with a recess which is provided in the peripheral surface of the supporter. The supporter is provided with a pressure equalizing bore which provides communication between the chamber and the outside. In addition, a conical reflector is provided so as to impart directivity to the ultasonic wave transmitted from the piezoelectric element.

Abstract: An ultrasonic transducer assembly comprising an injection-molded body member, a pair of piezoelectric ceramic members and a multi-pin connector is described. The piezoelectric ceramic members are electrically connected to the multi-pin connector by means of thin metallic ribbons. When assembled, the transducer assembly is detachably inserted in recesses provided therefor in the end of a hand-held probe.

Abstract: The invention is a backing material for an ultrasonic transducer. The backing material comprises a composite of tungsten powder, cerium oxide powder in an amount of 1.0 to 4.5% by weight tungsten, and an epoxy in a weight proportion to powder of from 4:1 to 50:1.

Abstract: Vapor pressure of liquid compositions is measured by a system having a cylinder member in which a reciprocal piston is disposed for movement to contain a sample of liquid and expand the chamber while measuring the pressure in the chamber until a substantially constant pressure is reached with increasing chamber volume. Liquid is circulated from a source such as a petroleum pipeline to the apparatus and continually through the expansible chamber in a retracted position of the piston. When a sample vapor pressure measurement is to be taken, the piston closes off a passage leading to the chamber and displaces liquid out of the chamber until a minimum volume is reached. The movement of the piston is then reversed to increase chamber volume while monitoring pressure and temperature to detect the onset of cavitation.

Abstract: The invention concerns an ultrasonic transducer for the determination of the acoustic power of an ultrasonic field (1) focused at a point (F). According to the invention, an ultrasonic transducer 2 contains a support structure (4) which has the shape of a spherical cup and whose center coincides with the focus (F) of the focused ultrasonic field (1), and a piezoelectric polymer foil (6) equipped on its respective surfaces (62, 64) with a conductive layer (8) is attached to said support structure. These measures ensure that the acoustic charge vibrations within the area formed by the piezoelectric polymer foil (6) are at least approximately in phase and that the respective surface charge vibrations can be measured with the aid of a single, continuous electrode without partial mutual cancellation.

Abstract: A dark field ultrasonic transducer is constructed with an outer annular spherical or conical transducer element and an inner spherical element. The outer annular element is excited and insonifies a small portion of a part surface near a discontinuity or crack with longitudinal waves or with surface waves. The inner dark field element is not focused to be sensitive to either reflected sound or waves reradiated from the surface waves, but detects sound scattered from surface discontinuities such as a crack edge. When surface waves strike a crack edge and restrike it after reflection from the bottom of the crack, two pulses are received and the time delay between them is a measure of crack depth. The crack shape and crack depth profile are determined as the part is scanned.

Abstract: The bubble point pressure, vapor pressure and liquid composition of hydrocarbon liquid flow streams is determined by causing the liquid flow stream to flow through a system having a plurality of eductors at selected various total pressure differentials across the eductors and measuring the pressure at the minimum pressure point or suction port of the eductors to obtain a reading of the vapor pressure. The system may comprise an array of three or more eductors arranged in parallel having flow regulating valves for controlling the flow rate and pressure drop across the eductors, respectively. The system may also comprise one eductor connected to a plurality of flow lines, each having flow control and/or shutoff valves arranged to provide for selective control of the flow rate and the resultant total pressure drop.

Abstract: The invention concerns a method for surveying the focal point (F, F') of a focussed ultrasonic field (8, 14) and an apparatus for carrying out the method. According to the invention an ultrasonic field (4, 12) produced by an ultrasonic transmitter (2) is measured at several sites in a plane in the path of the waves at the site of the imaging device (6). The values determined at these sites are compared with given reference values for which the position of the focus is known. In an advantageous device, one surface of the imaging device (6) is equipped with several piezoelectric transducers.

Abstract: An ultrasonic inspection device having an array of opposing transducers that longitudinally, transversely, and obliquely transmit sonic beams through tubular members having a range of diameters such that refracted beams meet on the inner surface of the members. Alternate halves of the array of transducers transmit and receive sonic beams reflected from defects in the tubular members using both the pulse-echo and pitch-catch methods.

Abstract: An ultrasonic transducer for generating an apodized beam of ultrasonic energy. A piezoelectric crystal element mounted in a housing generates on ultrasonic signal when electrically energized. A tungsten-epoxy layer mounted on the outer surface of the piezoelectric crystal element has a greater thickness at the periphery of the element than at the center, thus yielding an outwardly concave surface. The tungsten-epoxy layer provides a more uniform beam pattern.

Abstract: A material is disclosed for use as an adaptation layer in ultrasonic transducer units of the type which have a piezo-ceramic transducer. The material is porous, and the acoustic impedance of the material can be adjusted (in one embodiment, to 12.times.10.sup.6 kg/cm.sup.2 s) by adjusting the porosity of the material. In preferred embodiments, the material is piezo-electric and may have a porosity gradient.

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: 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 Reid Vapor Pressure of a hydrocarbon mixture consisting essentially of hydrocarbons selected from the same series is determined based on the actual temperature and vapor pressure of the hydrocarbons mixture. The thus determined Reid Vapor Pressure may be compared to a set point for the Reid Vapor Pressure with the results of the comparison being utilized to maintain the actual Reid Vapor Pressure substantially equal to the desired Reid Vapor Pressure.

Abstract: The disclosed scanning acoustic microscope comprises a solid lens body consisting of two sections of materials having different sound propagation characteristics but matching acoustic impedances. A lens is formed by the interface of said two sections and has a focal point coinciding with the apex of a sharply pointed tip formed at the free surface of one of said sections. The tip and the specimen to be investigated are immersed in a coupling medium having a relatively high acoustic absorption coefficient. The lens body carries an acoustic transducer on its surface remote from the tip for sending plane sound waves through the lens and tip onto the specimen. Acoustic waves reflected from the specimen are also received by this transducer. Acoustic waves transmitted through the specimen optionally may be received by a transducer arranged on the opposite side of the specimen. By appropriate processing of the received signals, high-resolution (10 nm) images of the specimen can be obtained.

Abstract: An ultrasonic inspection apparatus is shown for locating multiple defects in eccentric wall tubing or goods. A plurality of transducers are arranged in mated pairs, each of the pairs including a sender element for transmitting an ultrasonic shear wave and a receiver element for receiving a reflected ultrasonic wave component from the tubular goods being inspected. Each sender element is a point focus transducer having sufficiently high resolution to maintained detectability of defects in the tubular goods. Each receiver element is a wide focal width transducer having a large effective beam width area to compensate for eccentricity in the wall of the tubular goods.

Abstract: An acoustic microscope for analyzing an object in depth has aspherical lenses. It comprises two identical bars arranged in the extension of one another and provided on their facing ends with a cavity, said cavities defining a pseudo-hyperbolic focussing lens and objective lens, whereby the foci of said two lenses coincide and the lenses are linked by a mercury or gallium drop in which can be immersed the object to be analyzed. The bars are provided at their other ends with a piezoelectric transducer. These transducers are able to produce ultrasonics focussed within the object by the focussing lens and are able to detect the ultrasonics reflected or transmitted by the object via the objective lens. These are also means for analyzing ultrasonics reflected or transmitted by the object and means for displacing the object in the focal plane of the two lenses.

Abstract: A fuel monitoring system comprises a centrifugal air separation chamber having input and output Venturi devices. The system is arranged so that fuel from the fuel tank of the aircraft is pumped to the input Venturi device which due to the pressure drop therein, serves to release air from the fuel before it passes into the centrifugal air separation chamber where the air released from the fuel is separated out and exhausted from the chamber, whereas the substantially de-aerated fuel passes from the separation chamber into the output Venturi device, which produces a pressure drop enabling the vapor pressure of the de-aerated fuel to be determined therefrom.

Abstract: An ultrasonic detection apparatus having a transducer, a lens, and a damping ring, the damping ring being made of a material which is impedance-matched to the lens but which has a lower speed of sound so that stray noise in the lens travels into the damping ring and dissipates rather than remaining in the lens and reflecting back to the transducer as noise.

Abstract: An ultrasonic sector-scan probe comprises at least an array having a plurality of ultrasonic transducer segments, a window for transmitting and receiving ultrasonic waves and an ultrasonic wave propagation medium filled in a front space between the array and the window. A group of the ultrasonic transducer segments are selectively driven as an aperture and ultrasonic waves emitted therefrom are converged into a beam for transmission and reception. By partly or entirely changing the segments in the group with the ones outside the group the scan line is shifted to a new angle, and a member under test contacted with the window on the outside thereof is sector-scanned by the ultrasonic beam. The array is arranged so that scanning lines of the groups intersect at one point in the window or in its vicinity for sector scan.

Abstract: The Reid Vapor Pressure of a hydrocarbon mixture consisting essentially of hydrocarbons selected from the same series is determined based on the actual temperature and vapor pressure of the hydrocarbon mixture. The thus determined Reid Vapor Pressure may be compared to a set point for the Reid Vapor Pressure with the results of the comparison being utilized to maintain the actual Reid Vapor Pressure substantially equal to the desired Reid Vapor Pressure.

Abstract: The disclosure is directed to a method and apparatus for non-destructive inspection of a solid workpiece, such as a steel workpiece. In accordance with the method of the invention, ultrasound is generated at an annular ring or portion thereof and focused into a hollow substantially cone-shaped beam, or sector thereof. The beam is directed at the surface of the workpiece so as to establish shear mode ultrasound energy in the workpiece. Ultrasound energy is then received from the workpiece (e.g. by reflection or transmission) and characteristics of the internal structure of the workpiece can be determined from the received ultrasound energy. In the preferred embodiment of the invention, the beam is configured such that the ultrasound energy impinging on the surface of the workpiece is at a sufficiently large angle with respect to the normal to the surface such that primarily shear mode of ultrasonic energy will be established within the workpiece.

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 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.

Abstract: Dual focus ultrasonic transducers are provided for a diagnostic imaging effective aspheric radiating surface. The transducers are formed of disc-shaped piezoelectric material. An annular groove separates the piezoelectric material into an inner disc region and an outer annular region for simultaneous activation or activation of the inner disc alone. The focus is changed by a reed switch connection to the two transducer regions, which permits proximity switch control of the transducer operation in a shielded environment for good noise performance.

Abstract: An acoustic sensor and method of using same for determining the position of a tool from a workpiece are disclosed in which a piezoelectric transducer having a curved surface emits a sound wave which strikes the workpiece and is reflected back to the sensor. The sensor and tool are positioned relative to one another so that the workpiece will be near the focal point of the curved surface when the tool is operating. This positioning substantially overcomes the attenuation problems of high frequency sound waves transmitted through air.

Abstract: A device for focussing or collimating a beam of acoustic radiation comprises a body of acoustically transmissive material having first endface (12) coupled to a source of acoustic radiation (16, 18). The radiation is internally reflected by the side surface 20 of the body, this surface being of a shape such that it brings the radiation to a focus F after transmission through a second surface (14).

Abstract: The vapor-liquid ratio temperature of a liquid is determined for a specified vapor-liquid ratio and pressure by filling a chamber with a unit volume of the liquid. The capacity of the chamber is then expanded to generate a number of unit volumes of vapor equal to the specified ratio. Alternatively, a unit volume of the liquid can be discharged into an evacuated chamber having a fixed capacity equal to the number of unit volumes. The temperature of the liquid and vapor is maintained constant, and their pressure is measured when equilibrium is established. Deviations of the measured pressure from the specified pressure are translated into the vapor-liquid ratio temperature. In a gasoline blending environment, this temperature can be used to control the proportion of butane in the blended product.

Abstract: The invention is an apparatus useful in ultrasonic imaging to provide a highly focussed wave with a large depth of field. The apparatus comprises two or more coaxial, curved transducers, each producing adjacent, coaxial fields.

Abstract: An ultrasonic diagnostic imaging system is described in which a multi-element transducer array transmits a focused beam of energy from the transducer elements. As the depth of focus is varied between near and far field focusing under operator control, the nominal frequency of the transmitted ultrasound energy is varied correspondingly by the system, from relatively high frequency transmission in the near field to relatively low frequency transmission in the far field.

Abstract: Side-by-side transmitting and receiving transducers of a medical Doppler ultrasound device are covered by a converging lens of synthetic rubber material through which the speed of ultrasound waves is slower than the speed of the waves in soft body tissue. The lens has a planar inner face butted against the planar transmitting and receiving faces of the transducers and a convexly curved outer face including two portions each extending over both transducers, one of such portions being smaller and more sharply curved than the other. The composite lens focuses the transmitted ultrasound waves in two zones overlapping in range so that the same transducer arrangement can be used in obtaining velocity information from deep or shallow blood vessels.

Abstract: A method and apparatus for measuring Reid Vapor Pressure, as defined in the ASTM D-323 procedure, of liquid hydrocarbon materials wherein a sample of material is drawn from a sample can into a sample chamber containing a bellows and then to a measuring chamber. An expansion chamber, containing a bellows, connects with a measuring chamber for adjusting the amount of air within the measuring chamber and for setting the pressure within the measuring chamber before introduction of the sample so that RVP measurement occurs at the appropriate pressure.

Abstract: A method and an apparatus for generating short ultrasonic echo pulses by means of an ultrasonic transducer (2) utilizes a shift register (6) for storing a signal for excitation of said ultrasonic transducer. The stored signal is a weighted least squares filter signal to the transducer proper and is supplied to said transducer via a digital-to-analogue converter (7). Repeated adjustment of the stored signal can be effected by supplying, via an analogue-to-digital converter (11), the echo pulse signals from the ultrasonic transducer to a logic unit (12) for analysis.

Abstract: An ultrasound transducer having an annular acoustic aperture is utilized in combination with an echo-ultrasound imaging system having an FM detector. The off-axis transfer function characteristics of the annular transducer substantially improve the lateral resolution of the imaging system as compared with prior art systems which utilized round or rectangular transducer apertures.

Abstract: An ultrasonic microscope displays an ultrasonic wave image of a sample relatively and two-dimensionally scanned with respect to an ultrasonic wave beam transmitted from and focused by a transducer including a piezoelectric element and an acoustic lens. The F number of the acoustic lens is variably changeable while the scan in one direction of the two-dimensional scan is substituted by a time axis scan of the received echo.

Abstract: A multielement acoustic transducer comprising a metal plating which is formed by plating the convex surface of a low-melting metal having a plurality of convex semispherical holes and then fusing and removing the low-melting metal, the metal plating being used as a base electrode, a piezoelectric material which is formed on the base electrode, and a top electrode which is formed on the piezoelectric material, the piezoelectric material functioning as concave transducer elements.

Abstract: An apparatus and method for measuring particle agglomeration or dispersion in fluid mixtures, such as polymer melts, resides in a piezoelectric transducer, a spherical fused quartz lens, and a fluid housing. A repetitive, broadband, ultrasonic wave is produced by the transducer and is sent into the lens, which also serves to isolate the transducer from the mixture. The ultrasonic wave meets a spherical dimple at the end of the lens which focuses a portion of it into a diffraction limited spot or "interrogation zone". Since the intensity of the wave is large in the interrogation zone, small changes in the impedance of the fluid in this zone, caused by passing agglomerates, will cause large fluctuations in the intensity of the back scattered wave, which is monitored by the transducer between pulses and displayed by associated electronic elements.

Abstract: A doppler transducer which is particularly well adapted for use in fetal heartbeat measurements is comprised of a piston type transducer with a pair of lenses, which together provide both a divergent acoustic pattern and a flat surface for good acoustic coupling between the transducer and the mother's abdomen.

Abstract: An ultrasonic imaging device includes a transducer assembly for transmitting ultrasound pulses into a portion of a structure to be imaged and receiving ultrasound scattered by said structure portion and generating signals in response thereto, means to energize said transducer assembly to transmit said pulses, scanning means for progressively relating said transducer assembly to successive portions of said structure according to a scanning pattern, and receiver and signal processing means for assembling an image from said generated signals, the transducer assembly comprising separate transmitting and receiving transducers, one of said transducers being a simulated conical transducer having a line focus, and the other of said transducers having its axis in parallel alignment with said line focus, the scanning means being operative to move said line focus in relation to a structure to be imaged in accordance with said scanning pattern.

Abstract: A sensor utilizes the opposition of a fluid to physical displacement to provide information about the fluid itself, such as its quality as measured by its density or viscosity, or about the state of a fluid system which contains it, such as the fluid pressure existing at some point in the system. The sensor includes a fluid displacement device or element physically adapted to displace the fluid and repetitively urged into displacement by the application of a known impetus or urging force. The resulting motion of the element is then analyzed to obtain the information desired. The fluid displacement element may additionally perform a pumping function, or it may operate in a fluid stream externally powered. When employed as a pump, the sensor may provide information on the fluid pumped or on the state of the fluid system.

Abstract: The invention provides a highly focussed ultrasonic wave throughout a large depth of field without any mechanical motion. One embodiment of the invention providing two focussed fields includes a front to back arrangement of a converging lens, a transducer without any backing material to dissipate ultrasound, a converging lens, and a transducer. To focus in the far field, the front transducer transmits and receives via the front lens. To focus in the near field, the rear transducer transmits and receives via both lenses which collectively focus in the near field.