Light modulation sensor in a vortex shedding flowmeter
First Claim
1. A sensor for a vortex shedding flowmeter, the sensor comprising:
- a light source;
a light detector;
a sensor housing which includes a vortex shedding body for inducing vortices in a fluid on first and second opposite sides of the body which are representative of flow of the fluid, the sensor housing having a cavity which extends therethrough from the first to the second side;
first and second diaphragms supported on the first and second sides of the sensor housing in generally parallel relationship, the diaphragms covering the cavity and being positioned with respect to the vortex shedding body to respond to pressure differentials caused by the vortices induced in the fluid by the vortex shedding body;
reflector means positioned within the cavity for reflecting light;
waveguide means extending through the sensor housing to the cavity for transmitting light from the light source toward the reflector means and for transmitting light received after reflection from the reflector means to the light detector;
lens means positioned between the waveguide means and the reflector means for directing light from the waveguide means to the reflector means and for focusing the light reflected by the reflector means to a position proximate the waveguide means, the light received by the waveguide means after reflection by the reflector means being a function of relative positions of the waveguide means, the reflector means, and the lens means; and
coupling means connected between the first and second diaphragms for coupling movement of the diaphragms to at least one of the reflector means, the waveguide means, and the lens means so that light received by the waveguide means after reflection by the reflector means is a function of pressure differentials which cause deflection of the first and second diaphragms.
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Accused Products
Abstract
A sensor which provides an output signal representative of a parameter such as pressure, includes a reflector, a lens and a waveguide which are relatively movable as a function of the parameter. Light from a light source is transmitted by the waveguide toward the reflector. The lens, which is positioned between the waveguide and the reflector directs the light from the waveguide to the reflector and focuses the reflected light proximate a receiving surface of the waveguide. A sensor housing supports the waveguide, lens and reflector so that a relative physical displacement between the waveguide, lens and reflector occurs which is responsive to the parameter. The light received by the waveguide at its receiving surface is a function of the relative physical displacement, and thus a function of the parameter. The waveguide transmits the received light to a light detector which produces an electrical output signal which is a function of the received light and therefore of the parameter.
35 Citations
11 Claims
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1. A sensor for a vortex shedding flowmeter, the sensor comprising:
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a light source; a light detector; a sensor housing which includes a vortex shedding body for inducing vortices in a fluid on first and second opposite sides of the body which are representative of flow of the fluid, the sensor housing having a cavity which extends therethrough from the first to the second side; first and second diaphragms supported on the first and second sides of the sensor housing in generally parallel relationship, the diaphragms covering the cavity and being positioned with respect to the vortex shedding body to respond to pressure differentials caused by the vortices induced in the fluid by the vortex shedding body; reflector means positioned within the cavity for reflecting light; waveguide means extending through the sensor housing to the cavity for transmitting light from the light source toward the reflector means and for transmitting light received after reflection from the reflector means to the light detector; lens means positioned between the waveguide means and the reflector means for directing light from the waveguide means to the reflector means and for focusing the light reflected by the reflector means to a position proximate the waveguide means, the light received by the waveguide means after reflection by the reflector means being a function of relative positions of the waveguide means, the reflector means, and the lens means; and coupling means connected between the first and second diaphragms for coupling movement of the diaphragms to at least one of the reflector means, the waveguide means, and the lens means so that light received by the waveguide means after reflection by the reflector means is a function of pressure differentials which cause deflection of the first and second diaphragms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification