| 摘要 |
PROBLEM TO BE SOLVED: To improve the efficiency for detecting fine particles by providing a means of generating ultrasonic waves for forming the node of an ultrasonic standing wave at the condensation site of light and another means for generating ultrasonic waves for absorbing the wave front of ultrasonic waves at the node of the standing wave of the condensation site. SOLUTION: A measuring device consists of laser beam application equipment, a condensing lens 2, a sample cell, ultrasonic oscillators 4-1 and 4-2 for generating standing waves, a converging-type ultrasonic oscillator 5, and the like. While standing waves are oscillated from the oscillators 4-2 and 4-2 for standing waves, a sample liquid containing fine particles 40 is allowed to flow from a sample liquid inlet 3c to an outlet 3d, the fine particles 40 are aligned along the flow due to the standing waves. When ultrasonic waves 20c that are focused at the node of standing waves located at a light condensing site 20b of a laser beam 20a, the fine particles 40 are collected at a converging part 20d by the radiation pressure of ultrasonic waves and is guided to the light condensing site 20b and will not be guided to other nodes of standing waves, thus increasing the number of the occurrence of the breakdowns of the fine particles 40 at the condensing site 20b and hence improving the detection efficiency of the fine particles 40. |
