Patent ID: 9527119
Filing Date: 2016-12-27
CPC Classification: B08B,G01B,G05G,G06T

Claim Text:
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 air flowing through the sash opening has a face velocity, comprising: providing a laser device located on the hood to provide unobstructed access to a work area that forms the sash opening; providing a target element on the sash in line with a light emitting axis of the laser device; positioning the sash in a closed position wherein when the sash is in the closed position the target element is moved to a corresponding position indicating that the sash is closed; measuring a first distance between the laser device and the target element when the sash is in the closed position; positioning the sash in an open position to form the sash opening wherein when the sash is in the open position the target element is moved to a corresponding position indicating that the sash is opened; measuring a second distance between the laser device and the target element when the sash is in the open position; and determining the sash height based on a difference between the first and second distances wherein the determined sash height is used to adjust air flow to maintain the face velocity within a desired range.