Accession Number : AD0163679

Title :   Remotely Sensing Optical Tachometer.

Descriptive Note : Patent,

Corporate Author : OFFICE OF THE SECRETARY OF THE ARMY WASHINGTON D C

Personal Author(s) : Mary,Donald J. ; Davis,Harry J.

Report Date : 04 APR 1972

Pagination or Media Count : 4

Abstract : The invention relates to a remotely sensing optical tachometer for measuring the spin rate of a rotating member. The invention provides a simple optical system for measuring the spin and/or rate of change of spin, of, for example, an artillery shell or test projectile. The system provides a real-time readout of the spin rate, and requires no instrumentation aboard the projectile except for a small plane mirror that is attached obliquely to one end of the spinning projectile. The system directs a collimated beam of light that is reflected off the plane mirror back into the system where it traverses a stationary reticle that has alternating transparent and opaque sectors thereon. The frequency with which the light passes through the transparent portions of the reticle provides a direct indication of the spin rate of the rotating member.

Descriptors :   (*Tachometers, *Patents), Spin, Optical equipment, Sensors, Measurement, Projectiles

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE