Browse Prior Art Database

Air Flow Characterization in Vertical Laminar Flow Clean Rooms

IP.com Disclosure Number: IPCOM000039569D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Mueller, RP: AUTHOR [+2]

Abstract

A tool for measuring the air flow in a vertical laminar flow clean room is disclosed. The tool incorporates a Schlieren system for observing a volume of air, along with measurements from a hot wire anemometer placed on top of the Schlieren field. Referring to the figure, the Schlieren system 10 is schematically diagrammed. The heart of the system is a pair of parabolic mirrors 12 and 14. Light from source 16 passes through lens 18 and filter 20 and is then reflected by mirror 22 onto parabolic mirror 12. Parabolic mirror 12 then directs a parallel beam of light across the field of view 24 which is of interest. Then the parallel beam of light is again reflected by the second parabolic mirror 14 onto mirror 26 where it is in turn reflected through filter 28 and lens 30 before being recorded by optical detector 32.

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Air Flow Characterization in Vertical Laminar Flow Clean Rooms

A tool for measuring the air flow in a vertical laminar flow clean room is disclosed. The tool incorporates a Schlieren system for observing a volume of air, along with measurements from a hot wire anemometer placed on top of the Schlieren field. Referring to the figure, the Schlieren system 10 is schematically diagrammed. The heart of the system is a pair of parabolic mirrors 12 and 14. Light from source 16 passes through lens 18 and filter 20 and is then reflected by mirror 22 onto parabolic mirror 12. Parabolic mirror 12 then directs a parallel beam of light across the field of view 24 which is of interest. Then the parallel beam of light is again reflected by the second parabolic mirror 14 onto mirror 26 where it is in turn reflected through filter 28 and lens 30 before being recorded by optical detector 32. Optical detector 32 can be a video camera which is in turn connected to a monitor and/or a video tape recorder. In practice, a hot wire anemometer (not shown) is placed above the interested field of view. The hot wire anemometer generates a thermal disturbance which is picked up by the Schlieren optical system. The air flow speed is measured directly by the anemometer. The direction of air flow is indicated by the thermal plume which crosses the Schlieren field creating areas of different density that are visualized by the optical system. Flow direction can be directly observed on a monitor. B...