Abstract: A measuring apparatus, including a measuring device; a measuring element secured at one of its ends to the measuring device; a measuring body secured on the free end of the measuring element; a pendulum capable of oscillating the measuring element; a positioning motor for actuating the measuring device; and a logic control unit actuating the pendulum.

Abstract: A density meter includes a main body having a vertically elongated chamber to contain a test fluid. A passageway in the main body connects to the chamber near its bottom end. The passageway spans at least a bottom portion of the chamber and leads to the exterior of the main body. The chamber has in its lower end a liquid which is immiscible with and denser than the test fluid, the liquid also occupying at least part of the passageway. Access means are provided for admitting the test fluid to the chamber and evacuating it therefrom. Measuring means are provided for determining the location of the top surface of the liquid. The measuring means to determine the location of the liquid top is preferably ultrasonic.

Abstract: Fluid density measuring apparatus and method for directly measuring fluid density or indirectly measuring pressure, temperature, acceleration, flow velocity, differential pressure and other parameters affecting the apparatus. The apparatus includes a generally rigid hollow housing having openings through which fluid may flow to the interior of the housing, and a vibratory single-ended tuning fork mounted in the housing. The apparatus also includes circuitry for causing the tines of the tuning fork to resonate, for example, 180 degrees out of phase in a transverse direction, with the frequency of the tines varying with variation in the density of the fluid surrounding the tines. Circuitry is also included for determining the frequency at which the tuning fork tines resonate. When the density of the fluid into which the housing is placed changes, the frequency of vibration of the tines of the tuning fork is caused to change to provide a measure of the density change.

Abstract: Apparatuses and processes are described for the automatic determinations of fat contents of foods, such as dairy products, e.g., milk, wherein automatic density and solids content determining apparatuses are employed, together with a computer, to determine the fat contents of food samples being tested. The density determining apparatus is preferably one which is electromagnetically excited to vibrate at its natural resonant frequency, so that from the change in such frequency, compared to a control, the mass of the sample may be determined. The means for measuring the solids content is preferably an automatic volatility computer in which electromagnetic radiation (microwave energy) is employed to drive off the volatile material (usually mostly water) in the sample, which is automatically weighed before and after such volatilization.

Abstract: A vibration densitometer including a synchronous detector, a threshold detector, an integrator, an electromagnetic bridge driver, a piezoelectric crystal pick-off, a voltage controlled oscillator (VCO), a phase detector responsive to the crystal output and that of the VCO to control the VCO frequency and/or phase to provide an output signal of a frequency to energize the driver.

Abstract: Fluid density measuring apparatus and method for directly measuring fluid density or indirectly measuring pressure, temperature, acceleration, flow velocity, differential pressure and other parameters affecting the apparatus. The apparatus includes a generally rigid hollow housing having openings through which fluid may flow to the interior of the housing, and a vibratory single-ended tuning fork mounted in the housing. The apparatus also includes circuitry for causing the tines of the tuning fork to resonate, for example, 180 degrees out of phase in a transverse direction, with the frequency of the tines varying with variation in the density of the fluid surrounding the tines. Circuitry is also included for determining the frequency at which the tuning fork tines resonate. When the density of the fluid into which the housing is placed changes, the frequency of vibration of the tines of the tuning fork is caused to change to provide a measure of the density change.

Abstract: A rotational vibratory viscometer-densitometer for in-line process control and similar applications, having an elastic hollow metal tube extending between two clamps, and a relatively rigid transverse yoke secured to the tube at a point midway between the clamps. The yoke has magnetically permeable ends and a magnetically permeable center portion. Electromagnets adjacent one end of the yoke and the center portion thereof interact with the yoke to cause the tube to oscillate simultaneously in torsion and in flexure at the natural frequency of the tube in combination with the fluid within it. The amplitude of torsional oscillation is maintained constant by a torsional detector and control circuit, and the power required to maintain said amplitude is determined, said power being a measure of the viscosity of the fluid flowing through the tube.

Abstract: Apparatus employing ultrasonic pulse production at a transmit transducer at a known frequency is received at a receive transducer for sampling a liquid slurry of known composition, but unknown ratio, makeup of liquid, gas and fine, suspended particles. The transmission time is converted to digital form and an adjustable velocity-density slope factor is applied from empirical data to result in a readout voltage that directly relates to the density of the liquid slurry.

Abstract: A turbine engine fuel measuring and control system which incorporates a fluidic density sensor which is unaffected by variations in the physical characteristics of the fuel supplied to the engine.

Abstract: A pressure gauge for determining the pressure applied to a cylindrical vibrator by measuring the resonance frequency of the vibrator. The vibrator comprises a thin-wall cylindrical portion, a thick wall cylindrical portion extending from one end of the thin wall cylindrical portion and a thick wall end portion joined to the end of the thin wall cylindrical portion. The thin wall cylindrical portion is installed within a cover, to which the thick wall end portion is securely attached. The inventive vibrator type pressure gauge produces greater accuracy and reliability while also being resistant to external vibrations and pressures.

Abstract: An electromagnetically excited vibrator with arms carrying baffle members at their ends that are immersed in the flow to be measured is mounted at one or more vibration nodes to reduce loss of vibratory energy to the casing of the flow meter. A flat magnetically conducting cross shape can be mounted at a node in the middle, provided each cross beam of the cross is vibrated in flexure, and the two cross beams vibrate in phase opposition (counter stroke). Such a vibrator is excited by a similarly crossed pair of E-shaped cores with exciter and secondary windings on the middle legs of the cores, or by a coaxial re-entrant core with permanent magnet wafers set in the rim at respective locations separated by an air gap from the arms of the cross. In each case the vibrator can be firmly affixed to the central leg or legs of the core.

Abstract: A method and electronic circuit for measuring the density of substances flowing through an oscillating container densimeter that measures the temperature of the oscillating container to determine the temperature coefficient of the spring constant about the axis of oscillation.

Abstract: Apparatus for producing an output signal or indication directly proportional to the density of one or more gases or liquids. A probe holds a vibrating vane immersed in a fluid. The probe is suspended from a pipeline flange by a boss that has upper and lower portions connected together by a thin annular cantilever-like disc in a plane transverse to the probe axis. The boss supports telescoped inner and outer cylinders along an axis normal to the probe axis. The cylinders have an interference fit. The outer cylinder has a uniform outside diameter but an unstressed inside diameter that increases in direct proportion to its length. The same is true of the outside diameter of the inner cylinder. The inner cylinder supports the vane. A seismic mass which vibrates the boss is unsupported except at one end.

Abstract: This invention relates to a new method and new apparatus for determining fluid mass flowrate and density. In one aspect of the invention, the fluid is passed through a straight cantilevered tube in which transient oscillation has been induced, thus generating Coriolis damping forces on the tube. The decay rate and frequency of the resulting damped oscillation are measured, and the fluid mass flowrate and density are determined therefrom. In another aspect of the invention, the fluid is passed through the cantilevered tube while an electrically powered device imparts steady-state harmonic excitation to the tube. This generates Coriolis tube-damping forces which are dependent on the mass flowrate of the fluid. Means are provided to respond to incipient flow-induced changes in the amplitude of vibration by changing the power input to the excitation device as required to sustain the original amplitude of vibration. The fluid mass flowrate and density are determined from the required change in power input.

Abstract: A fluid density transducer with a vibrating tube 16 coupled to excitation pick-up transducers 32 utilizes an elliptical tube 16, having a small degree of ellipticity, to compensate for the variation in the natural frequency of vibration, resulting from a variation in the fluid pressure, i.e. a rise in fluid pressure tending to lower the frequency produces a more circular and hence stiffer tube cross-section tending to increase the frequency. A sealed evacuated chamber 36, formed by connecting together cylindrical nodal masses 24 and 26 using a flexible coupling 28, is used to enclose the vibrating tube 16, thus avoiding the risk of contaminating, and thereby also affecting the calibration of, the tube 16. The tube is supported at each end by a spring plate 12 fixed around its outer periphery to a collar 10 and around its inner periphery to an end-plate 25 of the nodal mass 24 or 26.

Abstract: Apparatus for measuring mass flow or density of fluid has a turbine mounted resiliently by torque rods within the fluid-flow line. The turbine has a number of vanes that extend radially to define passages parallel to the flow of fluid in the fluid-flow line. A torque driver causes oscillatory rotation of the turbine so as to give fluid in the passages a component of displacement at right angles to the passages. The turbine is driven simultaneously at two frequencies, displacement being sensed by a pick-off. The first frequency f.sub.90 is adjusted so that a 90.degree. phase difference is produced between the drive signal and the turbine displacement--the density of fluid being derived from this frequency. The second frequency f.sub.D is a fixed fraction F of the first frequency, the phase difference between the second frequency and turbine displacement being used to derive an indication of mass flow.

Abstract: The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time "t" between the initial and returning impulses. Considering the distance "d" between the spaced sonic surfaces and the measured time "t", the sonic velocity "V" is calculated with the equation "V=2d/t". The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0.degree. and 40.degree. C. and for specific gravity values between 1.05 and 1.30.

Abstract: A vibration type density meter includes a mechanical oscillator or resonator having a resonance frequency variable with the density of a specimen fluid around the oscillator. The resonator is of a cylindrical configuration with flanges at the ends thereof, at least one of the ends being open for introducing specimen fluid into the resonator. The meter also includes means for exciting the resonator, means for detecting oscillations of the cylindrical resonator, a cover coupled to the flanges of the resonator in surrounding relation to the latter, and circuit means for processing a frequency signal from the oscillation detecting means, and by arithmetic operations derive and display the density of the specimen fluid being measured.

Abstract: A device for measuring the mass flow of a fluid consists of a body which is arranged to resonate under the influence of a travelling flexure wave. Various embodiments of the invention are described. In certain embodiments in which the resonating body is in the form of a cylinder, the frequency of resonance is related to the mass of fluid flowing over the surface of the cylinder. In other embodiments, the wave velocity of the flexure wave is modified by a fluid flowing over the surface of the cylinder and amplitude modulation is introduced into the resonating flexure wave. The amplitude modulation is related to the mass of fluid flowing and an output indicative of the mass flow is produced. In further embodiments the body is in the form of a flat vane. The wave velocity of the flexure wave is modified by the fluid over the surface of the vane, and the wave velocity is monitored by comparing the relative phases of the flexure wave at different points along the vane.

Abstract: A quartz tuning fork in a chamber adjacent a gas pipeline carrying a turbine flowmeter. The chamber is connected across the flowmeter turbine to receive a gas at a flow rate high enough to cause the tuning fork to vibrate. A main output frequency is developed which is directly proportional to the product of a function of the tuning fork period of vibration and the turbine meter output signal frequency. The main output frequency is then counted and is displayed on an indicator, the constants of the circuit being so selected that the indicator displays total flow in units of mass. The density sensor measures the gas density at the turbine flowmeter rotor location. This obviates the requirement for expansion factor corrections.

Abstract: Apparatus for use in the measurement of a variable comprises a housing; a first transducer which is mounted within the housing and which is arranged to produce an electrical transducer output signal which depends both on the value of the variable and on the value of at least one calibration constant of the transducer; an encoder which is mounted within said housing and which is programmed with information relating to the value of said at least one calibration constant, said encoder being arranged to produce an electrical encoder output signal representative of the value of the said at least one calibration constant, and connector means carried by said housing and electrically connected to the first transducer and to the encoder to receive signals functionally related to the transducer and encoder output signals, the connector means being connectible to a second transducer for the transmission of the said functionally related signals thereto.

Abstract: A method of and apparatus for sampling granular material where a substantially vertical sampling tube is subjected to axial, and/or rotational oscillations to reduce the vertical vector component of the friction force between the granular material and the tube to be substantially equal to the weight of an elemental disc of the material in the sampling tube. The acceleration force on the disc is substantially zero and the material has no pressure gradient or bulk density gradient.

Abstract: A fluid density transducer with a vibrating tube 16 coupled to excitation pick-up transducers 32 utilizes an elliptical tube 16, having a small degree of ellipticity, to compensate for the variation in the natural frequency of vibration, resulting from a variation in the fluid pressure, i.e. a rise in fluid pressure tending to lower the frequency produces a more circular and hence stiffer tube cross-section tending to increase the frequency. A sealed evacuated chamber 36, formed by connecting together cylindrical nodal masses 24 and 26 using a flexible coupling 28, is used to enclose the vibrating tube 16, thus avoiding the risk of contaminating, and thereby also affecting the calibration of, the tube 16. The tube is supported at each end by a spring plate 12 fixed around its outer periphery to a collar 10 and around its inner periphery to an end-plate 25 of the nodal mass 24 or 26.

Abstract: A quartz tuning fork is provided which may be employed in several instruments for measuring the properties of fluids. The tuning fork may be employed, for example, in a gravitometer, a barometer, an altimeter or a temperature sensor.

Abstract: A vibration densitometer probe including an internal piezoelectric crystal, a canted vane, and an isotropic ring to support the vane.

Abstract: A vibration type transducer is provided in which various physical quantities, for example, the pressure, density, force and temperature are measured from the natural frequencies of the mechanically vibrated vibrator.The vibrating element is vibrated in a plurality of vibration modes and a plurality of resultant frequency signals are processed to obtain signals associated with the various physical quantities. The system is not influenced by physical quantity other than the physical quantity to be measured.

Abstract: The invention relates to a measuring probe for the acoustic determination of the specific gravity of a liquid. The probe includes a holder to which is attached at opposite ends thereof a ceramic piezoelectric transducer disc and a reflector disk. A reference element having a known acoustical impedance has one end thereof abutting the transducer disc and the other end thereof spaced from the reflector disc to form a sampling space therebetween.

Abstract: A vibration densitometer probe assembly including a web partly covering a bore in an annular support, the web having a central hole therethrough, a probe shaft sealed through the hole, and a compressed packing in the bore bearing upon the probe shaft.

Abstract: A vibration densitometer having a permanent magnet biased magnetostrictive drive unit, a maximum efficiency, and an automatic search for a resonant frequency signal.

Abstract: A densitometer of the vibrator type is disclosed wherein a spring mass system is immersed in a liquid whose density is to be determined. The system includes a pair of coaxial cylindrical masses in the form of fluid couplers having spaces which are open to the liquid. A torsion spring connects both cylindrical masses through mechanically stiff coupling means. The coupling means include a pair of high impedance transducers positioned at the shear interfaces normal to the common axis of the system, so as to take substantially the full torsional shear load between the spring and the cylindrical fluid couplers without contributing to the spring effect. The compliance of the torsion spring allows oscillatory motion of the spring mass system around its axis. An output signal having a high signal-to-noise ratio is provided at the natural resonant system frequency.

Abstract: A flowmeter determines the density of a fluid stream by periodically shifting a carrier sonic signal at a carrier modulation frequency and detecting the peak received energy after the carrier sonic signal traverses the stream. The flowmeter may additionally determine the temperature, volumetric flow, and mass flow of the fluid stream.

Abstract: A vibrating fluid density transducer 10 provides a gas density measurement D, used in conjunction with a flowmeter signal f.sub.B to meter the mass of gas fed through a pipeline. D is subject to errors dependent upon the velocity of sound C in the gas. The errors are corrected to yield Da by application of a correcting formula (block 18) in which C is introduced by calculation (block 17) from a measurement of gas pressure P by a transducer P. The value of C may alternatively be measured directly, computed from a measurement of specific gravity or in the case of a liquid, be inferred from D or be preset.

Abstract: A device for measuring the density of a liquid relies on the generation of resonant modes in a torsional vibration set up in a paddle which is immersed in the liquid. The frequency at which a resonance mode, usually a fundamental, is produced is a function of the density of the liquid. A feedback circuit is described which varies the frequency of an oscillator producing the vibrations so as to enable the frequency at which the resonance mode exists to be automatically found. Transducers for generating and detecting the torsional vibration are located at one end of a rod above the surface of the liquid, and the paddle is mounted on the other end of the rod.

Abstract: Ultrasonic waves are applied to a test liquid of an unknown density, and the acoustic parameters of the liquid are measured. The difference is then detected between the acoustic parameters of the test liquid and those of a standard liquid of the same temperature. The difference thus detected is added to the known density of the standard liquid, thereby obtaining the density of the test liquid.

Abstract: A transducer for sensing density, pressure or pressure difference in fluids comprises a resonantly vibratable cylinder as its sensing element. The cylinder has a mounting ring at one end, the mounting ring being clamped against a base member by means of a spring arranged to exert a substantially constant clamping force on the mounting ring. An outer cover fits over the cylinder, the cover having a flange which is directly bolted to an upstanding annular rim of the base member and a depending skirt portion in which the spring is integrally formed by machining.

Abstract: Apparatus for measuring the value of a fluid variable comprises a vibrator tube through which the fluid may be passed and which is mounted for clamped-clamped flexural vibration in a holding structure whose stiffness is at least 40% greater than that of the vibratory tube. A driving coil is carried by the holding structure and is arranged in operation to produce the clamped-clamped flexural vibration of the vibratory tube. A pick-up coil is arranged in operation to respond to vibration of the vibratory tube. A support supports the holding structure and the vibratory tube by way of an isolator which substantially prevent transmission of vibration between the support on the one hand and the holding structure and vibratory tube on the other hand.

Abstract: A vibration densitometer having a magnetostrictive drive with a coil and a crystal pickup. A loop circuit including a driver amplifier provides the coil with a voltage twice that ordinarily provided. Further, the driver amplifier is unusually small, inexpensive and accurate.

Abstract: A method of calibrating a densitometer to meter two gases of different molecular structures by empirically deriving a hole size function of the indicated error for one gas in the density equation of the other and performing tailored reboring of the hole in a production unit in accordance with the hole size derived from the function by determining the full scale error thereof.

Abstract: An ultrasonic densitometer for measuring the density or a density related parameter of a fluid has at least one transducer assembly that transmits and receives torsional waves guided in an axially extending sensor that is at least partially immersed in the fluid. The sensor has a noncircular cross section, typically rectangular, with dimensions, aspect ratio, frequency and bandwidth selected to limit dispersion. This non-circularity creates an inverse and substantially linear relation between the density of the fluid and the velocity of the torsional wave in the sensor. To meet special requirements, the sensor can take a variety of forms including axially curved, axially profiled, segmented or longitudinally composite. This densitometer, alone or in combination with conventional auxiliary ultrasonic measuring systems, can measure fluid density, density profiles, liquid level, viscosity, mass flow rate, gas pressure, and boiling or condensation, including measurements of flowing fluids in small conduits.

Abstract: Disclosed is a mass flow rate meter having two U-shaped flow loops, means for vibrating the flow loops like the tines of a tuning fork, timing means on the loops for sensing the difference in times between the passing of the sides of the loop through the static plane of the loops, and sensing means for determining which side of the U-shaped tubes went through the static plane first. The time between the passing of the sides of the loops during one half cycle of the vibrations of the loops is combined with the time of another half cycle of the vibrations dependent upon which side of the loops pass through the static plane first. An embodiment is further disclosed having a microprocessor for combining the times, and for comparing these times with a selectable variance from the time of a predetermined set of vibrations before the present time measurement is accepted. Electronic circuitry is also disclosed which improves the time measurement of the timing means.

Abstract: The device includes an oscillation body and an electronic circuitry component connected to an oscillation detector and to plural oscillation generators, and including a period of frequency meter, phase shifters supplying the generators with an excitation signal shifted in phase relative to the detector signal, and a modulator. The phase angle between the detector and excitation signals, and the oscillating frequency, are varied substantially periodically within a given interval at a frequency which is lower than the oscillation frequency. Control elements control the phase and frequency position of the interval as a function of the variation of the ratio of the detector signal to the excitation signal, and of the relation between the variations, within the interval, of the detector and excitation signals and the phase angle therebetween.

Abstract: An apparatus for measurement of density, particularly of liquids and gases, by determination of the characteristic frequency of a tube-shaped bending-type oscillator which is filled with the measuring substance, which oscillator is connected with a tensioned body, the tension of which is dependent upon the temperature and/or the pressure of the measuring substance. The tensioned body is bending-slack (a string). A member is provided which guarantees that the deflection of the bending oscillator is transmitted to the string and the restoring force of the string is transmitted to the oscillator.

Abstract: An apparatus for measuring the physical properties of material in which the sensing means is a tubular sensing member having a longitudial slot extending from one end to the other end. A support connected to the tubular member approximately midway between the ends of the tubular member and diametrically opposed to the slot. Electrical coil means extend longitudinally through the inside of and around the outside perimeter of the tubular member one or more times. An electrical driving circuit is connected to the coil means for vibrating the sensing member and an electrical sensing circuit is connected to the coil means for measuring the vibration of the sensing member.

Abstract: A vibration densitometer having a magnetostrictive drive with a coil, and a crystal pick-up. A loop circuit including a driver amplifier provides the coil with current which leads the crystal voltage by 90 degrees for maximum efficiency.

Abstract: A welded vibration densitometer probe to obviate frequency shifts due to temperature changes.

Abstract: A vibration type liquid density meter comprising a base, a connector having a mass substantially smaller than said base, two hollow cylindrical elongated pipes each having two ends, one end of each pipe connected to the base, and the other end of each pipe connected to the connector with the pipes disposed substantially parallel to each other and a piezoelectric element attached to the connector for driving the pipes into self excited oscillation at their natural frequency. The liquid to be measured is supplied through the base, pipes and connector and the density of the liquid is measured by the frequency of oscillation with corrections for temperature.

Abstract: An immersible liquid densitometer is disclosed employing an immersible vibrator. The vibrator includes one or two masses which are resiliently supported and which contain perforations which fill when the vibrator is immersed in the liquid. When the vibrator is immersed, the frequency of vibration is affected in proportion to the density of the liquid filling the perforations. Thus, measurement of the frequency of vibration may be used to determine the density of the immersing liquid. For maximum accuracy, the configuration and vibratory mode of the masses are selected for minimum energy coupling to the liquid. Typically, a cylindrical configuration is selected vibrating in a rotational mode. Under these conditions, the drag during vibration is due primarily to skin friction and a high Q, high accuracy measurement is achieved.

Abstract: A flow meter for measuring mass flow is disclosed having two vibrating U-shaped tubes, a means for vibrating the tubes, and sensors for detecting the coriolis force couple which results from the vibration and the flow of the material to be measured through the meter. The U-shaped tubes include spaced apart inlet and outlet sections connected to a fixed member at one end, and having the sensors at the other end thereof. The fixed ends are more closely spaced together than are the other ends having the sensors for increasing the moment arms acted on by the coriolis force couple for more easily detecting twist of said U-shaped tubes. The U-shaped tubes also are arranged to have the same natural of frequency for longitudinal oscillations and for torsional oscillations.

Abstract: A densitometer and sonic velocimeter are provided through use of a transducer to provide energy transductions and for providing vibratory energy. In this way, longitudinal wave energy can be imparted to the surrounding fluid. Indications from the transducer provide a representation of the fluid density.

Abstract: The device comprises a thin vibratable plate to be introduced into the substances whose density is to be measured, and the plate is held by a holder at a holding point and is vibrated by at least one vibration exciter in operative engagement with the plate. The vibrations of the plate are detected by at least one vibration detector operatively associated with the plate at a point spaced from the point or points at which vibrations are imparted to the plate. An electronic unit is connected to the vibration exciters and the vibration detector and forms therewith an oscillator having an input from the vibration detector and an output supplied to the vibration exciters. The vibration exciters are so positioned with respect to the plate, and so energized by the electronic unit, that the plate vibrates in a manner such that two nodal lines intersect in the range of each holding point at which the plate is supported by a holder.