METHOD AND APPARATUS FOR MEASURING DIAMETER AND DISTRIBUTION OF MICRO BUBBLE AND MICRO LIQUID DROP AND OPTICAL SYSTEM FOR MEASURING DIAMETER AND DISTRIBUTION OF MICRO BUBBLE AND MICRO LIQUID DROP

摘要

A method for measuring the diameter of a micro liquid drop and the spatial distribution of micro liquid drops by measuring the diameter of an unsharp image due to defocusing and the number of interference fringes thereof is applied to measurement of micro bubbles and applicable even if the spatial distribution density of micro liquid drops or micro bubbles is high. A liquid space where a micro bubble (10) is floating is irradiated with a sheet-like parallel laser beam (2), and a defocus image of the micro bubble (10) to which the laser beam is applied is picked up on a defocus plane (8) through an objective lens (6) in a direction at an angle υ with respect to the direction where the laser beam travels. The interference fringes (9) in the defocus image (10') of the micro bubble (10) are counted, and the diameter of the micro bubble (10) is determined according to formula (4).