System for detecting a position of a fume hood sash
First Claim
1. A method for determining a height of a sash opening formed by a movable sash relative to an edge defining one end of a cutout in a fume hood, wherein the hood is connected to an exhaust fan and a damper for providing a ventilating air flow having a face velocity corresponding to an area of the sash opening within a predetermined range, comprising:
- providing a laser device on the hood;
providing a reflector on the sash relative to a light emitting axis of the laser device;
positioning the sash in an open position to form the sash opening;
measuring a first distance between the laser device and the reflector when the sash is in the open position;
positioning the sash in a closed position;
measuring a second distance between the laser device and the reflector when the sash is in the closed position;
determining the sash height when the sash is in the open position based on a difference between the first and second distances;
adjusting a speed of the exhaust fan or a damper opening based on the determined sash height to maintain the face velocity within the predetermined range.
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Accused Products
Abstract
A method for determining a height of a sash opening formed by a movable sash in a fume hood. The method includes providing a laser device on the hood and providing a reflector on the sash. In addition, the method includes positioning the sash in an open position to form the sash opening and measuring a first distance between the laser device and the reflector when the sash is in the open position. The method also includes calculating the sash height based on the first distance.
4 Citations
13 Claims
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1. A method for determining a height of a sash opening formed by a movable sash relative to an edge defining one end of a cutout in a fume hood, wherein the hood is connected to an exhaust fan and a damper for providing a ventilating air flow having a face velocity corresponding to an area of the sash opening within a predetermined range, comprising:
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providing a laser device on the hood; providing a reflector on the sash relative to a light emitting axis of the laser device; positioning the sash in an open position to form the sash opening; measuring a first distance between the laser device and the reflector when the sash is in the open position; positioning the sash in a closed position; measuring a second distance between the laser device and the reflector when the sash is in the closed position; determining the sash height when the sash is in the open position based on a difference between the first and second distances; adjusting a speed of the exhaust fan or a damper opening based on the determined sash height to maintain the face velocity within the predetermined range. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system for determining a height of a sash opening formed by a movable sash relative to an edge defining one end of a cutout in a fume hood, comprising:
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a laser device attached to the hood; a reflector attached to the sash, wherein the sash is movable to an open position relative to the cutout in the hood to form the sash opening, wherein the laser device measures a first distance defined by the laser device and the reflector when the sash is in the open position, wherein the sash is movable to a closed position relative to the cutout in the hood, wherein the laser device measures a second distance defined by the laser device and the reflector when the sash is in the closed position, and wherein the laser device determines a difference between the first and second distances to determine the height of the sash opening. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification