Laser Doppler Anemometry (LDA) is well established in fluid dynamic research. Most wind tunnel and water tunnel experiments are supported by LDA measurements due to their ability to measure instantaneous velocities with high precision. However, the classical LDA equipment is very voluminous, has large power consumption and needs skilled staff for operation. Because LDA is a nonintrusive measuring procedure with no calibration needs, its use outside the laboratory would be very interesting. Process control and calibration of classical fluid sensors can be considered to be the main applications. Along with semiconductor lasers and detectors instead of gas lasers and photomultipliers, a dramatic reduction in spatial volume and power consumption results. Therefore, essential requirements for a sensor concept are fulfilled. The paper presents a miniaturized LDA as a sensor head. It has the dimensions of 4.7 cm by 4.5 cm by 5.7 cm. It consumes less than 3 W electrical power on a 12 V power supply. The measuring distance is 9.5 cm. The velocity range which can be covered reaches from 5 m/s up to 500 m/s.
Stephan Damp, Stephan Damp,
"Miniature laser Doppler anemometer for sensor concepts", Proc. SPIE 1418, Laser Diode Technology and Applications III, (1 July 1991); doi: 10.1117/12.43831; https://doi.org/10.1117/12.43831