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 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 a 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.
5 Citations
13 Claims
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1. A method for determining a height of a sash opening formed by a movable sash 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 a 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 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 moved to an open position to form the sash opening and wherein the laser device measures a first distance between the laser device and the reflector when the sash is in the open position and wherein the sash is moved to a closed position and the laser device measures a second distance between 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