Measuring and testing – Liquid analysis or analysis of the suspension of solids in a... – Viscosity
Patent
1995-07-20
1997-09-23
Williams, Hezron E.
Measuring and testing
Liquid analysis or analysis of the suspension of solids in a...
Viscosity
73 32A, G01N 1110
Patent
active
056707096
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to transducers for the measurement of attributes of flowable media, for example the density, viscosity, mass flow or the level of a fluid or a flowable solid.
RELATED ART
It is known for example from GB-B-2202944 to provide a transducer which essentially comprises a resonator in the general form of a tuning fork for the measurement of attributes of flowable media. The fork is usually constructed from two parallel beam elements of which the longitudinal axes are laterally spaced apart. These beam elements may be tubes which contain the fluid or tines which are immersed in the medium. When tubes are used there is usually a limitation in the size of the bore, limiting the flowrate, and it is usually necessary to provide some means for directing the medium through the tubes, for example a pump. If the device is adapted for insertion into the flowable medium, there is no need for ancillary equipment such as pipe fittings and the transducer can usually be made smaller and easier to install. However, devices employing a pair of tines are susceptible to error or inconvenience arising from the entrapment of debris between the tines, such debris affecting the desired vibration and accordingly the accuracy of measurement.
SUMMARY OF THE INVENTION
The invention is generally concerned with the provision of improved and versatile transducers and more particularly an improved transducer which reduces some of the disadvantages associated with a device comprising a pair of spaced apart tines.
The present invention is based on a structure which in preferred forms can be described as a coaxial resonator, for example a resonator composed of two vibratile beam elements having a common base or root, a first of the beam elements being disposed at least partially within the other. In the manner of a tuning fork, when one beam element, for example the outer beam element, is displaced at its distal end, it creates at its base or root a torque moment, which is equalized by the sympathetic movement of the other beam element, there being practically no net displacement at the common base or root. The structure provides a highly efficient vibrating system, having a natural frequency dependent on the physical characteristics, such as the mass and stiffness of the beam elements.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other features and aspects of the invention are more conveniently described with the aid of the accompanying drawings:
FIG. 1 illustrates in simplified form one embodiment of a transducer according to the invention; and
FIG. 2 illustrates a second embodiment of a transducer according to the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 illustrates by way of example one embodiment of a transducer according to the invention. This transducer 10 is in the form of a coaxial resonator and comprises two vibratile beam elements, one located inside the other. The outer beam element 11 in this example comprises a tube and the inner element 12 is in the form of a substantially solid tine. Both elements 11 and 12 are either integral with or secured to a base or root 13.
Like a tuning fork, when one beam element, for example the element 11, is displaced or vibrated, it vibrates in the manner of a cantilever beam and accordingly creates at its base or root a torque moment, which is equalized by the sympathetic movement of the other beam element to create practically no resulting displacement at the base or root. The result is an efficient vibrating system with a natural frequency dependent on the mass and stiffness of the elements 11 and 12.
In the present embodiment, the base 13 has a rearwardly extending flange 14 defining a well or partial enclosure wherein an appropriate means for inducing vibration in the resonant structure and for sensing either displacement, strain or other characteristic of the resonant structure may be disposed. This is not the only possible location of such drive means and sensing means but the location specified here is
REFERENCES:
patent: 2142854 (1939-01-01), La Pierre
patent: 3062040 (1962-11-01), McKennell et al.
patent: 3282084 (1966-11-01), Banks
patent: 3349604 (1967-10-01), Banks
patent: 3525252 (1970-08-01), Kocatas
patent: 3625058 (1971-12-01), Endress et al.
patent: 4547691 (1985-10-01), Valdois et al.
patent: 4740726 (1988-04-01), Umezawa
patent: 4920787 (1990-05-01), Dual et al.
patent: 5317908 (1994-06-01), Fitzgerald et al.
patent: 5323638 (1994-06-01), Langdon
Politzer Jay L.
Williams Hezron E.
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