Abstract
Fine particle size measurement technique with laser interference fringes is proposed as one of the in-line measurement technique to the diameter of several hundred nano meter particles. The objective of this study is to examine the principle of this measurement technique with laser interference fringes. First, we visualize the flow structure in the flow cell with Particle Image Velocimetry (PIV). Flow structure in the flow cell is appeared stable. Second, we visualize the laser interference fringe images with high-speed video camera. And we identify the fringe images moving through the test cell. Finally, we measure the time variation of the intensity of the laser interference fringes by using two photodiodes. It is confirmed that the voltage signal depends on fine particle size. Also, the voltage signal depends on flow rate.
