1
J Vincent Fitzgerald, Frank J Matusik, Donald W Nelson: National Metal and Refining Company, Arthur L Lessler, June 25, 1985: US04524610 (74 worldwide citation)

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 ...


2
Philip D Anderson, Michael J Rybicki: Resonator sensors employing piezoelectric benders for fluid property sensing. Videojet Systems International, Piper Marbury Rudnick & Wolfe, April 4, 2000: US06044694 (63 worldwide citation)

Resonator sensors namely piezoelectric benders are used for sensing fluid viscosity and density. The benders are inserted into a liquid to be monitored. An input voltage is applied to the bender causing it to vibrate in the liquid at a resonant frequency. Output voltage amplitude or frequency are mo ...


3
Mark J Rudkin, David I H Atkinson: Fluid transducer. Sanford J Asman, May 8, 1990: US04922745 (57 worldwide citation)

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 ...


4
Harold E Hager, J D Sheldon Danielson: System for sustaining and monitoring the oscillation of piezoelectric elements exposed to energy-absorptive media. The Board of Regents of the University of Washington, Christensen O Connor Johnson & Kindness, November 15, 1988: US04783987 (47 worldwide citation)

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 ...


5
Rudkin Mark Jonathan, Atkinson David Ian Heaton: Fluid transducer.. Schlumberger Electronics, September 14, 1988: EP0282251-A2 (45 worldwide citation)

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 ...


6
Robert H Hammerle: Method and apparatus for measuring viscosity in a liquid utilizing a piezoelectric sensor. Ford Motor Company, Paul K Godwin Jr, Clifford L Sadler, May 3, 1988: US04741200 (45 worldwide citation)

A piezoelectric element energized to exhibit thickness-shear mode vibration is utilized to measure the viscosity of liquids. Electrodes, of an inert material are bonded to the major faces of the disc shaped crystal and are of a lesser diameter than the crystal surfaces so as to provide a concentric ...


7
Rork Gerald D, Simon Frank N: Viscosimeter and densitometer apparatus. Honeywell, Dahle Omund R, September 9, 1975: US3903732 (37 worldwide citation)

A viscosimeter and a densitometer are provided through use of a transducer or transducers to provide energy transductions and for providing vibratory energy. In this way, either shear wave energy or longitudinal wave energy or both can be imparted to the surrounding fluid. Indications from the trans ...


8
Frederick M Discenzo, Chung Chiun Liu, Donald L Feke, Laurie Ann Dudik: Micro-viscosity sensor and lubrication analysis system employing the same. Reliance Electric Industrial Company, Himanshu S Amin, John M Miller, John J Horn, February 15, 2000: US06023961 (36 worldwide citation)

A micro-viscosity sensor for measuring the viscosity of a lubricant. The micro-viscosity sensor including at least one finger-like element or an array of finger-like elements vertically extending from the surface of a semiconductor base, the at least one finger-like element being oscillated at a des ...


9
Virgilio dos Reis Cardoso Igreja: Molten glass viscosity and/or level meter. Tilton Fallon Lungmus & Chestnut, June 26, 2001: US06250136 (35 worldwide citation)

A device for the on-line measurement of viscosity and/or level of molten glass, converting the values of these variables into proportional electrical signals. The device comprises one sensor head connected to an electronic control unit and to a data processing unit. The sensor head comprises a fixed ...


10
Joseph B Seale: Conversion of liquid volume, density, and viscosity to frequency signals. Chris A Caseiro, Thomas L Bohan, July 9, 1996: US05533381 (35 worldwide citation)

Volume of a working liquid in a sensing chamber is measured via a first mechanical resonance frequency. A second resonance may be measured to discriminate interacting volume and density effects, yielding corrected volume, density, and liquid mass. A probability of bubbles present in the liquid is in ...