Portable Laser Velocimeter for Stack Velocity Measurements.

摘要

The report describes the design and development of a short range,laser velocimeter together with the analysis of optical velocity measurement techniques over ranges up to 1500ft. This laser velocimeter operates on an interference-backscatter principle. It is portable and designed to measure velocities of flowing particle laden gases in power plant ducts or stacks at relatively close ranges. The instrument is composed of a sensing head cabinet and an electronics cabinet. The sensing head incorporates a laser illuminator,beam forming optics and photodetector. The electronics cabinet contains a signal processing circuit,spectrum analyzer,and power supplies for the laser and spectrum analyzer. The design,construction and preliminary testing of the velocimeter are discussed. Also presented is an analysis of optical velocity measuring devices for extended range operation. Three types of optical velocimeters were considered: Doppler shift,interference-fringe;and a reticle velocimeter. (Author)