Design of Photo-Detector for Particle Sizer Using Laser Diffraction

레이저 회절성에 의한 입자 크기의 계측을 위한 센서 설계

We design a multi-element photo-detector to measure the size of particles using the diffracted light energy distribution. The light energy that is scattered by particles in the collimated laser beam is collected by the Fourier transform lens and directed to the multi-semicircular concentric annular detecters. The scattered profile measured by the photodetector is sampled by a 32 channel analog-to-digital converter. A nonnegative least squares analysis translates the light energy distribution into the corresponding unique particle size distribution.