Laser Doppler Velocimeters.

Abstract

This paper makes a survey of the laser Dopplereffect type meters, which were demonstrated at the international exhibition Fizika - 75 (presumably held in the U.S.S.R.). More than 200 firms took part from 21 countries. The laser meters exhibited were designed for analysis and velocity measurement of gases, liquids and solid substances. All the meters had the characteristics of absence of mechanical contact with the substance being measured, an absolute method of calibration, independence of the reading from density, temperature and pressure effects, and a wide measuring range. The paper gives a few words on the general principle of operation of these meters, and then goes on to give brief descriptions of the instruments. Two schematic diagrams are given. There is mention of the British Firm, Precision Devices. (A.L.)