Mie Scattering as a Technique for the Sizing of Air Bubbles.

A technique has been developed which allows the radius of a bubble in a fluid to be accurately measured without disturbing the bubble. Results are presented which show that radius measurements of single air-bubbles in water can be achieved by shining a He-Ne laser on the bubble and measuring the light scattered at 80 degrees. Light intensity measurements at a scattering angle of 55 degrees were used to calibrate a photodiode detection system and to demonstrate the correlation of data with Mie scattering theory. The photodiode was then moved to 80 degrees for actual radius measurements. This technique was accurate to within 3 for bubbles with radii less than 80 microns. Author