an apparatus for measuring the presence of microorganisms using fluorescent substances . a number of samples are measured continuously by enclosing the entire reacting and measurement sections within a thermostatically controlled enclosure . a number of samples are placed in containers with reactive liquids and placed in the reacting section of the enclosure . after the specified time within the enclosure , the container is rotated to the measuring section . the remaining liquid is filtered and activating light shined therethrough . the fluorescent light given off is measured to indicate the presence of microorganisms .