Abstract: This invention relates to measurements of characteristics of a comminuted material by an ultrasonic method. The method of monitoring parameters of a solid phase of suspension comprises the steps of producing a Lamb wave and gamma-radiation and passing them respectively through a test medium (2) along the wall of a measuring vessel (1) and through the test medium (2) placed therein, measuring the amplitude of the Lamb wave and the intensity of gamma-radiation, while using, as the test medium, separately a standard liquid and the analyzed suspension to find the parameters of the solid phase of suspension by way of the ratio of the measured values.

Abstract: A liquid level sensor comprises an elongated tubular member with two open ends contained in an elongated cylindrical container vessel in an arrangement wherein the two extremities of the elongated tubular member extending through the wall of the elongated cylindrical container vessel are respectively open to a liquid medium that rises through the elongated tubular member to the same level as the free surface thereof and to an ambient air above the free surface of the liquid medium; wherein the level of the liquid medium is determined from a natural frequency of flexural vibration of a section of the elongated tubular member partially filled with the liquid medium; which combination may further include another section of the elongated tubular member completely filled with the liquid medium, wherein the density of the liquid medium is determined from a natural frequency of flexural vibration of the section completely filled with the liquid medium and the level of the liquid medium is determined from a combinati

Abstract: A viscosity measuring transducer especially useful for process control of fluids. The transducer oscillates an immersed blade sensor in the direction of the plane of the blade in order to maximize generation of shear waves and to minimize generation of compression waves. The transducer includes a bar which penetrates and is secured and peripheral sealed to an isolation plate which serves to protect the oscillation driver and pickup adjacent one end of the bar from the sensor blade to be immersed in a fluid adjacent the other end of the bar. Either the bar is relatively rigid and the isolation plate is relatively compliant, or vice versa. In the former case the isolation plate acts as an intrinsic flexible member of the oscillating system of the transducer; and in both cases the isolation plate constitutes a strong impermeable seal between the fluid and the driver/pickup mechanism.

Abstract: A gas flow correction sensor for producing an output signal proportional to the ratio between line pressure and line temperature for gas flowing in a line, for use in correcting the output of a volumetric flow meter connected in the line, comprises a sealed chamber containing a fixed mass of a reference gas. The sealed chamber includes a bellows portion subjected to line pressure, thus maintaining the reference gas at line pressure. Additionally, the sealed chamber is thermally insulated and includes at least a portion disposed in a thermowell immersed in the line, so as to maintain the reference gas at line temperature. A vibrating quartz density sensor is also mounted in the thermowell, so as to produce an output signal whose frequency is proportional to the density of the reference gas, which can be shown also to be proportional to the desired line pressure to line temperature ratio.

Abstract: A densitometer (10) provides a chamber (24) within which a ferromagnetic bob (27) is shuttled back and forth by alternate driving of two coils (32 and 34). Measurement circuitry (FIG. 2) determines the density of the fluid inside the chamber (24) by comparing the stroke times in opposite directions.

Abstract: An apparatus for measuring density of media moving through a conduit included therein comprises one or two vibrating sections under two different flexural vibrations vibrating at two different natural frequencies which are functions of the stiffness of the vibrating sections of the conduit, density of the media moving therethrough and viscosity of the media as well as the viscosity of the ambient air surrounding the vibrating sections of the conduit. A mathematical combination of the two different natural frequencies of the vibrating section or sections of the conduit eliminates the dependence thereof on the viscosities and determines the density of media accurately independent of the viscosity.

Abstract: A fluid mass flow sensor uses the effect of aerodynamic drag on a vibrating object. The drag damps the resonance oscillations of the vibrator in an amount proportional to the mass flow. An electronic feedback circuit associated with the mass flow sensor has the effect of allowing for fast response time despite the use of a high Q vibrator and allows for electronic calibration of the device.

Abstract: Apparatus and accompanying methods for use therein for a Coriolis mass flow rate meter which is substantially immune to noise, and more particularly, to such a meter that is substantially unaffected by noise that occurs at substantially any frequency different from a fundamental frequency at which the flow tube(s) in the meter vibrate. Specifically, the meter relies on measuring mass flow rate by determining the phase difference that occurs between real and imaginary components of the discrete fourier transform (DFT) of both the left and right velocity sensor waveforms evaluated at the fundamental frequency at which the flow tubes vibrate. The fundamental frequency is located, during an initialization operation, by providing a power spectrum, determined through use of the DFT of one of the sensor signals and then selecting that frequency at which the magnitude of the power spectrum reaches a maximum value.

Abstract: A fluid density measuring device or densitometer computes, electronically, the density of a fluid by measuring the resonant frequency of an excitation signal provided to a density transducer (11) immersed in the fluid. The frequency at which resonance occurs in the circuit (13, 15, 17, 21, 23, 25, 29, 31, 37, 41) will vary according to the density of the fluid, and this information is used by measuring electronics (31, 37, 41, 43), including a programmed microprocessor (43), to calculate the density of the fluid. The output of the microprocessor (43) may be a display of fluid density information or may be transmitted to a fuel gauge.

Abstract: A method and system determines the density of a liquid, such as aircraft fuel, by measuring the amplitude of the reflections of ultrasonic pulses from the faces of the walls of a reference material. A transducer is used to transmit an ultrasonic interrogation pulse through a liquid to the reference material. The density of the reference material is known, and its boundaries are well defined. The interrogation pulse is reflected from the faces of the reference material boundaries to provide first, second and third return pulses that can be used to determine the density of the liquid. The density determination is accomplished by determining characteristic impedances, reflection coefficients and transmission coefficients as a function of the returned pulse amplitudes.

Abstract: A single vibrating tube transducer comprises a tube (4) held between two nodal masses (6) which are attached to the tube (2) close to their respective centers of gravity (16). Each nodel mass (6) has an extended portion (14) which is attached at its free end to the opposing nodal mass by an arrangement of metal ligaments (18). Vibrating means (19) and sensing means (20) drive and detect the tube motion respectively. The tube has discontinuities (28) adjacent to the vibrating means (19) and the sensing means (20), to ensure the desired mode of resonance is achieved. Acoustic baffles (30) prevent inaccuracies due to internal acoustic resonance in the transducer.

Abstract: The apparatus of the present invention detects the resonant frequency of a vibratory member in contact with the fluid in order to determine the density or pressure of the fluid. The vibratory member is disposed in a housing to form a cavity with no flow communication between the side of the vibratory member facing into the cavity and the other side of the vibratory member. The vibratory member is vibrated by an annular piezoelectric device which may be attached to one or both sides of the vibratory member. An amplifier and feedback circuit regulate the frequency of oscillation of the piezoelectric device to that of the resonant frequency. The piezoelectric device may be comprised of several separate sections or several sections with partial interruptions in the piezoelectric material. Instead of the vibratory member and the piezoelectric transducer combination, the vibratory member may be constructed from a single fixed piezoelectric device with another piezoelectric disc mounted thereon.

Abstract: A method of determining the specific gravity of a fermentable liquor during fermentation is disclosed. Specific gravity is determined from measurements of original gravity, velocity of sound, and temperature.

Abstract: A damping device for damping mechanical vibrations in a small diameter elongated member, such as a waveguide carrying torsional strain waves, includes a damping material contained inside a housing on the waveguide, the damping material is a viscous liquid that does not evaporate or change viscosity over a wide temperature range and which has additives for providing adequate mass density for damping vibrations in such elongated member. The use of a viscous liquid and additives for changing the mass density permits varying the mass density to match impedances and reduce the amplitudes of any reflective waves. The viscous liquid preferably comprises a silicone base oil partially filled with zinc oxide and metal particles to give the characteristic of stable viscosity across a wide range of temperature and provide the necessary attenuation while obtaining good coupling of the damping material to the elongated member.

Abstract: Solute concentration measurement apparatus comprises a container (1) for a solution together with an ultrasonic transmitter (2) and receiver (3). A signal from the transmitter (2) passes through the solution to be detected by the receiver (3). A clock (5) and microprocessor (6) determine the speed of sound in the solution and hence the concentration of solute present.

Abstract: A transducer for measuring a parameter of a fluid, such as density or viscosity, comprises two generally parallel tines extending from a common yoke, forming a tuning fork adapted to be immersed in the fluid. The tines are excited to vibrate resonantly and in anti-phase by one or more piezo-electric exciting elements, which are housed in one or more cavities within the tines or the yoke. The vibrations are sensed by one or more similarly-housed piezo-electric sensing elements. The tines are shaped to enhance their sensitivity to the parameter to be measured: for example they are provided with re-entrant surfaces to enhance density sensitivity, or elongated in the direction in which they vibrate to enhance viscosity sensitivity.

Abstract: An oscillation period of an oscillating tube of an oscillatory densimeter is detected while the oscillation of the oscillating tube is maintained by applying an external force in the form of a pulse signal to the oscillating tube in one direction each time the tube passes the original place in that direction so that a stable oscillation free from any influential distortion can be obtained.

Abstract: A device for detecting the viscosity or specific gravity of liquid has a vibrator, a vibration transmission shaft provided thereon with the vibrator and adapted to transmit the vibration of the vibrator, and a detection terminal connected to one end of the vibration transmission shaft so that the detection terminal immersed in liquid can be vibrated by the vibration of the vibrator. A mass is disposed in a hook-shaped relationship with the vibration transmission shaft at the other end of the vibration transmission shaft. A housing encloses the mass and serves as a grip. A spacer is interposed between the housing and the mass so that the housing is spaced apart from the mass at the peripheral surface thereof, and a vibration absorbing member is mounted on the mass so that the mass is supported by the housing through the vibration absorbing member.

Abstract: A device for detecting the viscosity or specific gravity of liquid includes a vibrator made of piezoelectric ceramics and capable of vibrating about its axis, a vibration transmission member, a detection terminal to be immersed in liquid, the viscosity or specific gravity of which is to be measured, and a vibration sensor provided on the vibration transmission member. The vibrator and detection terminal are connected to each other through the vibration transmission member. The detection terminal is vibrated within the liquid by the vibration of the vibrator transmitted through the vibration transmission member. The vibration sensor detects the vibration of the detection terminal immersed in the liquid.

Abstract: A guided torsional wave sensor has a cross-section with a strong interaction of torsional wave energy and the surrounding fluid, such that a wave propagates in the sensor with a functional dependence on a single fluid characteristic. In one embodiment, the sensor body is optimized for fluid density. Diamond, polyhedral and curved-sided embodiments are described. In another embodiment, the sensor body responds to fluid viscosity. This embodiment is preferably hollow, and may include threaded, fractal or roughened surface features to enhance viscous coupling. Different systems include further sensors, sensors with portions of differing profile, and special mounting or activation structures.

Abstract: A device for measuring fluid density, the device comprising a silicon substrate having a micro-engineered cantilevered beam fabricated on it for use as a density sensor. The beam is at the end of a tube and has a contact manufactured on its end and a contact manufactured on the substrate below the contact. Means for causing said structure to vibrate and for detecting a characteristic of the vibration are provided, the characteristic being dependent on the density of the fluid to be measured.

Abstract: Apparatus and accompanying methods for implementing both an accurate densimeter and a net oil computer utilizing a common Coriolis meter assembly is described. This apparatus measures density of an unknown fluid by first determining the period at which both flow tubes contained within a dual tube Coriolis meter oscillate while the unknown fluid passes therethrough. The apparatus then squares the result. Thereafter, the density of the unknown fluid is determined as a linear function that relates the squared tube period measurement for the unknown fluid, and squared tube period measurements and known density values for two known fluids, such as air and water, that have previously and successively passed through the meter during calibration.

Abstract: A vibrating transducer for detecting the resonant frequency of a vibrating diaphragm and using that frequency to determine the pressure or density of a fluid contacting the diaphragm. The device includes a container having a diaphragm separating the cavity in the container into two chambers with the diaphragm preventing flow communication between the two chambers. A first fluid inlet in flow communication with the first chamber introduces fluid to the first chamber with that first chamber having an acoustic compliance less than the mechanical compliance of the diaphragm. The second fluid input is in flow communication with the second chamber and introduces fluid into the second chamber. By controlling the acoustic compliance of the chamber with respect to the diaphragm accurate measurements of the density or pressure of the fluid can be obtained.

Abstract: Method and apparatus for evaluating the density profile of a wood-derived specimen. A sample of the material is mounted on a lathe and rotated at high speed. An acoustic emission transducer is coupled to a cutting tool, brought into contact with the specimen to produce an AE signal, as the tool is moved across the thickness of the rotating sample. The acoustic emission signal is then transformed into an electrical signal and the resultant electrical signal is amplified and transmitted to a second amplifier for further amplification and analysis of the signal.

Abstract: Apparatus for determining the amount of biological material in a fluid medium, typically the concentration of bacteria in a fermentation chamber, has a test cell through which a medium can be passed with bacteria or after bacteria have been removed by filtration. In the test cell a vibratory element is excited to a resonant frequency indicative of density and a comparison of medium density and medium plus bacteria density reveals the bacteria concentration.

Abstract: A density measurement instrument measures the density of a fluid by determining the frequency of oscillation of a vibrating tube filled with the fluid. An electronic excilation system vibrates the tube and the frequency of oscillation is representative of the density and the temperature. The frequency is accurately measured. A temperature control system controls the temperature of the fluid during oscillation by comparing a single temperature set point with the measured temperature of the sample. Based on this comparison, current in a first direction or in a second direction is applied to a Peltier element for heating or cooling the sample. Substantially continuous temperature readings and adjustments of the current are thus provided. The temperature information may be applied to an external data link or to a display.

Abstract: An oscillation period of an oscillating tube of an oscillatory densimeter is detected while liquids of which densities are to be measured are introduced into the oscillating tube. When the oscillation period exceeds a predetermined threshold, a time for which the introduction of liquids should be further continued is determined by multiplying the time from the start of the introduction to occurrence of the exceeding by a predetermined ratio.

Abstract: A method of measuring aircraft fuel quantity and density in a fuel container using an ultrasonic transducer; a stillwell liquid fuel; a computer control, an indicator and an altitude sensor. The computer control includes a central processing unit connected to each of the ultrasonic transducers. The altitude sensor is connected to the central processing unit. The indicator means is connected to the central processing unit. The stillwell is supported by the container. Each ultrasonic transducer is supported within the stillwell by the container. The liquid fuel is supported within the container. An ultrasonic signal is transmitted from the transducer within the stillwell. The reflected ulrasonic signal is received by the transducer within the stillwell. The round-trip time period from sending to reciving the signal is measured. The quantity of fuel in the container is determined from the round-trip time period and stored data on the container volume in the central processing unit.

Abstract: A specific gravity detector includes an electromechanical vibrator having a central axis and capable of vibrating about the central axis, a transmission shaft having one end thereof connected coaxially to the vibrator, and a detector member connected coaxially to the other end of the transmission shaft. The detector member is immersed in liquid, the specific gravity of which is to be measured and vibrated about the central axis of the vibrator within the liquid by the vibration of the vibrator transmitted through the transmission shaft to measure the specific gravity of the liquid based on a variation in the resonance frequency of the vibrator corresponding to the moment of inertia of the liquid.

Abstract: A fluid meter, such as a density meter or a Coriolis-type mass flow meter is disclosed in which the fluid tube is mounted to allow for expansion and contraction relative to a base to which opposite ends of the tube are mounted. In the preferred embodiments, a single, rectilinear flow tube measuring section is bounded at each end by a thermally insulating wall having a linear bearing which allows longitudinal axial movement while restraining transverse movement. Disposed distally of the linear bearing relative to the flow tube measuring section is means for accommodating the expansion and contraction of the measuring section. In one embodiment this is in the form of a laterally coiled tube portion. In a serial double-tube flow sensor, three serial rectilinear and parallel sections of the flow tube pass through linear bearings similar to that of the single tube, with arcuate sections joining adjacent rectilinear sections.

Abstract: Apparatus for use with a densitometer having a probe with an output and a probe driver for driving the probe includes a loop circuit coupled between the probe output and the probe driver. An amplifying circuit is coupled in the loop circuit to amplify the signal provided by the probe. A phase/gain control device is also coupled in the loop circuit between the amplifying device and the probe driver. The phase/gain control device controls the loop circuit to provide a loop gain of at least one and a substantially zero degree phase shift between the probe driver and the probe output signal. The amplifying device includes an op-amp which is preferably coupled to a shielded cable carrying the probe output signal. The shield conductor and one input of the op-amp are held at ground potential, and the op-amp acts to hold the center conductor at ground potential also. With the center conductor held at ground potential, the output signal from the probe varies with current, not voltage.

Abstract: Apparatus for use in measuring fluid density comprises a fluid carrying helical sample tube 50 made of a conductive material for passing current therethrough. A cylindrical coil fixing sleeve 58 form surrounds the helical sample tube and engages the tube to prevent relative movement of the turns. A high flux permanent magnet 60 is carried on one post 54 and is aligned along the axis of the tube. The magnetic field established by magnet 60 and the pole extension 64 will subject each current-carrying length element of the sample tube to an axial force, the sum of these forces resulting in a bodily axial movement of the sample tube. The sample tube is excited to spring resonance by passing current through the sample tube. The resonant frequency is measured and is indicative of the mass of the fluid contained in the coil and thereby of the fluid density.

Abstract: There is disclosed Q-loss compensation apparatus for a piezoelectric sensor such as a quartz crystal microbalance or other resonant vibratory device wherein the vibration amplitude of the device is controlled by negative feedback in a manner to obviate the effect of energy loss associated with viscous damping of a large liquid drop on the quartz crystal face serving as an environment for an experiment to measure mass deposited on the crystal face. The specific apparatus includes an oscillator circuit for the vibratory device in which two generally similar variable gain amplifiers provide the regenerative feedback for maintaining oscillation. The negative feedback amplitude control circuit serves to maintain constant the output from the variable gain amplifier following the quartz crystal in the oscillator loop, and it thus maintains at a near constant value the product of the crystal vibration amplitude and the square root of the total gain in the oscillator loop.

Abstract: The disclosed system includes a piezoelectric crystal exposed to an energy-absorptive medium of interest. A crystal oscillation circuit is included for sustaining oscillation of the crystal in contact with the fluid. To accomplish this, the circuit includes feedback elements for providing automatic gain control of the amplifier portion of the oscillator. In this manner, the conditions required for crystal oscillation are maintained independent of variations in the medium the crystal is exposed to. Information regarding the gain adjustment and oscillation frequency of the crystal are applied to a microprocessor-based system for determining fluid characteristics such as viscosity, density, and dielectric constant. Alternatively, this information is used to correct for the influence of such parameters on the resonant behavior of piezoelectric crystals undergoing mass change, in the analysis of, for example, corrosion, adsorption and electroplating.

Abstract: Suspensions, liquid emulsions and the like are monitored with ultrasonic waves from bottom to top of a column of such to determine if there has been alteration in the original compositions thereof, the method being particularly adapted for determining the stability of coal-aqueous slurries.

Abstract: Suspensions, emulsions and the like are monitored with apparatus which pulses ultrasonic waves through a suspension at elevations from bottom to top along a column of such suspension to determine if there has been alteration in the original composition thereof, the apparatus being particularly adapted for determining the stability of coal-aqueous slurries.

Abstract: A fluid sampling chamber assembly for noninvasive sensing of a fluid having a chamber with a sensor wall for acoustic coupling therewith, an apparatus for coupling a transducer of a transducer assembly with the sensor wall, a preapplied acoustic coupling agent and a relatively rigid connector member mounted to the chamber around the sensor wall with a portion around a probe access opening in retentive overlying relationship with the acoustic coupling agent to prevent run off of the coupling agent before use. A cover is releasibly attached to the connector for protectively covering the access opening and sensor location. The cover permits gaseous sterilization of the sensor wall because ribs carried by the releasible attaching means block the releasible attaching means from making a gaseous tight seal with the connector.

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: A method and apparatus for measuring steam quality of wet or two-phase flowing steam includes a flow-through densitometer comprised of two parallel tubes connected to two common nodes, a vibrator for causing the tubes to vibrate, and a transducer for detecting the frequency and amplitude of the vibrations. A temperature probe detects the temperature of the steam, and a computer is used to monitor the vibrations and temperature and to calculate steam quality. The computer can also be used to control the vibrator. An intake sampler is positioned in a flowing steam line to divert a representative sample of the wet steam into the densitometer. The bulk density of the steam is determined as a function of the fundamental frequency of the densitometer with the steam flowing therethrough, and the steam quality is determined as a function of the bulk density and vapor density, which is a function of temperature.

Abstract: The density of polyethylene is determined by measuring the velocity of ultrasound through the material. The determination of density is based on the correlation between the velocity of ultrasound in semi-crystalline materials and their density, and involves the measurement of time delays of a transmitted ultrasonic pulse from each of the front surface of the material the rear surface of the material and a reflector which are immersed in a liquid. Operating within a selected frequency range provides measurements of density while eliminating viscoelastic effects.

Abstract: An enclosure 1 has a measurably variable volume chamber 2, a control for controlling the temperature of the fluid contained therein and apparatus for measuring the pressure of the fluid. The chamber is selectively connectable, on the one hand, to a filling device 6, for introducing the sample, and on the other hand to a fluid extraction apparatus 7, 8. The enclosure 1 is selectively connectable to a tubular loop 9 having a circulation pump 10 and apparatus 11 for measuring the density of the sample of circulating fluid. By varying the volume of chamber 2, the thermodynamic characteristics of monophase and diphase fluids can be accurately determined. The apparatus is especially useful for the study of fluid of hydrocarbon deposits.

Abstract: A method and apparatus are disclosed which relate to measuring the quantity and thermal insulating value of fibrous material as it is delivered from a source to another location. A feeder mechanism is provided for delivering the material such as insulation to housing from which it is dispensed ultimately to some cavity such as wall space or surface. The housing includes rotary vanes which divide the housing into a number of separate chambers. A measuring system provided with electronic circuitry and acoustical apparatus delivers a controlled acoustical signal to the chamber containing the fibrous material. A sensor senses acoustical signal generated by a source but altered by the fibrous material within the chamber. Signals corresponding to the source signal and the sensed signal are both fed to a comparator which in turn emits a signal proportional to the volume and density, or thermal insulating value of material contained in the chamber.

Abstract: A vibrating tube densimeter characterized by separate electrical conductors attached to and moving with the tube. By interaction with a constant magnetic field in which they move, and in cooperation with an electronic circuit outside the invention, one of the conductors vibrates the tube and the other senses the vibration. The novel design is simple and permits operation at high temperatures.

Abstract: Apparatus for correctly aligning a pair of sensor probes relative to a sample chamber location in a biological fluid sensor apparatus for sensing fluid in a sample chamber. The sensor probes are carried at the end of a pair of arms mounted for pivotal movement toward one another and the sample chamber location. The distance between these sensor probes when sensing with different sample chamber assemblies of possibly different dimensions established by a blocking member which blocks the arms from movement toward one another beyond a preselected limit. The sensor probe assembly includes a transducer assembly with a transducer housing having a tip and a transducer mounted in a sensing position at the tip together with a guide assembly having a guide housing and structure for mounting the transducer assembly protectively therewithin for relative movement between an inoperative position and an operative position.

Abstract: A piezoelectric device for measuring the pressure of a gas like medium comprises two oscillators disposed opposite to each other in a substantially closed system by intermediate introduction of the gas to be measured. The measuring is performed by defining a transfer factor from the first piezoelectric oscillator to the second piezoelectric oscillator, whereby the first piezoelectric oscillator is definitely excited and the measuring signal is picked up by the second piezoelectric oscillator.

Abstract: A device for installation on the auger filler cone of dry product dispensing equipment which comprises one or more ultrasonic resonators arranged so as to measure the acoustic impedance of the product within the auger filler cone without interfering with the flow of the augered product. The acoustic impedance can be calibrated to give a density measurement. The device is particularly well-suited for measuring the density of a dry product in the dispensing equipment used in the packaging industry, where a specified amount by weight must be dispensed into containers. Since an auger-type filling machine dispenses a precise volume for each degree of rotational movement of the auger, constant monitoring of the density of the product within the auger cone allows the weight of the dispensed product to be rapidly and accurately determined during the filling process.

Abstract: Ultrasonic process and apparatus for monitoring and measuring the evolution with time of physico-chemical and biological phenomena. There is plunged into the medium or media (4) to be monitored a bar (3) into which ultrasound (2) is injected in order to collect secondary echoes (F2, F3) due to numerous reflections from the lateral surface of the bar (3) brought into contact with the medium (4), one of the secondary echoes (F2) is selected and the evolution with time of the amplitude of this echo is recorded, this representing the evolution of the medium being monitored, in particular the setting of concrete or the polymerization of a resin.

Abstract: In order to identify the density of a particle, an acoustic wave is focused on the particle and the reflected wave is detected by the focusing transducer. The ratio of the Fourier transform of the transmitted wave to the received wave is an indication of density. A particle to be examined may be suspended in a low boiling point medium and a transducer may be located within the medium by melting a localized region of medium by means of temperature control liquid flowing through the transducer assembly.

Abstract: There is provided a pressurized flow densitometer for the determination of he PVT properties of fluids. The densitometer comprises a tube flown through by the fluid to be tested, an exciter and sensor means for causing said fluid-filled tube to vibrate and for sensing the frequency and amplitude of vibrations thus induced, a frequency meter for processing the output of the sensor means, a thermostat for maintaining the tube and the fluid at a selectable, constant temperature, a pump connected to, and arranged upstream of, the tube for moving the fluid through the tube at controllable rates of delivery. The densitometer further comprises a flow resistance connectable to, and arranged downstream of, the tube to pressurize the fluid in dependence on the rates of delivery, at least one fluid-containing bottle attachable to the suction line of the pump, and a bypass valve arranged between the tube and the flow resistance, whereby flushing of the tube is accomplishable by opening the bypass valve to the atmosphere.

Abstract: This invention relates to a method for assessment of the condition, and cge of condition, of the liquid fill for chemical projectiles by analyzing the vibrational characteristics of the projectile and fill. It is a method by which the condition of the liquid fill in a projectile can be assessed without requiring cutting, drilling, and/or altering the structure of the shell or payload. This non-destructive technique can be used with projectiles filled with toxic or hazardous materials and can occur within the confines of storage buildings. The system for incorporating the method of the invention includes a projectile which is freely suspended and then struck with a device causing the projectile and the fill to vibrate. The natural vibrational characteristics of the projectile and fill are measured and recorded and can be compared to model data to ascertain any changes in the physical characteristics of the fill.