METHOD AND DEVICE FOR DETECTING SIZE OF PARTICLE IN LIQUID

摘要

Even when there are only a few minute particles as impurities contained in a liquid, the particle size is detected accurately and at low cost. A method for detecting the size of a particle by detecting a diffraction fringe generated by the particle contained in a liquid by a light detecting means comprises the steps of detecting the diffraction fringe by a first light detecting means and a second light detecting means which are disposed apart along the flow direction of the liquid, measuring a peak time difference T2 which is the difference between points in time at which peak values of detected signals by the first light detecting means and the second light detecting means appear and an area SQ of the waveform of the detected signals, and detecting the size of the particles contained in the liquid on the basis of the measured peak time difference T2 and area SQ.