In order to investigate the influence of particle parameters on the evaluation of the light diffraction pattern analysis, 2-dimensional model particles were produced by photographing round particles and rectangular ones on the slide film respectively, and were experimentally analysed in the He-Ne laser diffraction system. The particle parameters were size, concentration, and shape of the particle images on the film. The results coincided with the microscopic ones within the standard deviation of 1 to 15 %.
The particle concentration, defined as the ratio of the particle image area to the total slide area, was suggested to be above 2 % in order to eliminate errors in analysing the intensity of the diffraction pattern. For rectangular particles, the evaluated equivalent size approached only to the width of the particle.