Particle fallout/activity sensor

US5412221A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Ihlefeld M. Curtis · Orlando, US
• Robert C. Youngquist · Cocoa, US
• John S. Moerk · Titusville, US
• Kenneth Rose · Goleta, US

Key dates

• Filing date: Apr 26, 1994
• Grant date: May 2, 1995
• Expiry date: Apr 26, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N15/06
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A particle fallout/activity sensor measures relative amounts of dust or other particles which collect on a mirror in an area to be monitored. The sensor includes a sensor module and a data acquisition module, both of which can be operated independently of one another or in combination with one another. The sensor module includes a housing containing the mirror, an LED assembly for illuminating the mirror and an optical detector assembly for detecting light scattered off of the mirror by dust or other particles collected thereon. A microprocessor controls operation of the sensor module's components and displays results of a measurement on an LCD display mounted on the housing. A push button switch is also mounted on the housing which permits manual initiation of a measurement. The housing is constructed of light absorbing material, such as black delrin, which minimizes detection of light by the optical detector assembly other than that scattered by dust or particles on the mirror. The data acquisition module can be connected to the sensor module and includes its own microprocessor, a timekeeper and other digital circuitry for causing the sensor module to make a measurement periodica…