| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydrodynamics light detecting device and a method capable of measuring a particle size of a fine particle in a fluid with a high accuracy. SOLUTION: An ultrasonic transducer 40 of a probe 10 vibrates a probe tip 24 and a dispersant fluid with a selected frequency, and light scattered from a particle 32 in the dispersant fluid and light reflected from a tip surface end 25 are mixed in a light detector 18 to generate a Doppler beat signal. An electronic mixer 50 receives the Doppler beat signal and generates a power value signal for each higher harmonics of a specified frequency. A digital calculator 86 calculates a particle movement amplitude signal and determines the percentage of particles vibrating in a specified frequency. With a theoretical model of particle movement in a vibrating dispersant medium, a particle size distribution is measured by the percentage. |
