AN INVESTIGATION OF THE FLUORESCENCE VISIBILITY METHOD FOR DROPLET SIZING IN SPRAYS

Studies conducted several years ago demonstrated that the visibility of signals produced when fluorescent droplets passed through the probe volume of a crossed beam optical system could be used as a means of measuring droplet size. In the present investigation this technique was examined in detail both analytically and experimentally. The theoretically derived visibility function was verified experimentally over a droplet size range from 8 to 220 (mu)m. An electronic processor was designed to allow direct measurement of signal visibility. With this processor preliminary measurements of the size distribution in a pressure atomizer spray were made. Sauter mean diameters computed from these measurements were compared with those obtained from two other techniques