This project is a passive device that can, on command, sense and measure the amount of dust and other contamination accumulated on its sensitive surface. The principle used is to illuminate the surface at grading incidence with light from a diode laser. The surface consists of a glass plate exposed to the environment of interest. Discrete particles collected on the plate scatter some of the light, and a portion of the scattered power is detected by a large area silicon sensor beneath the plate. Additional diode lasers and features make it possible to measure separately the scatter caused by dust, molecular films, and erosion and to do this while exposed to the sun. The initial concept has a smooth, washable, exposed surface with no protrusions and a device package about the size of a small, thick book. The basic principles have been demonstrated, and the sensitivity should extend from MIL-STD-1246 levels below 100 to above 700. There are two types of applications. One is for devices geared for spacecraft use with emphasis on low weight and ruggedness. The other is for routine use in vacuum test or production systems with emphasis on convenience, software interface, standardized design, and low cost contamination, detection, particulate, autonomous, sensor, molecular, real-time, scattering STATUS: Phase I Only
