The Statistical Fractal Character of Random Signal Generated by Optical Sensor in Optical Particle Counter

The scattering pulse signal counting distribution generated by optical sensor is the full reflection of the irregular particles´ size distribution in the optical particle counter. For studying the statistical character of the random signal, we establish the two-parameter pulse model based on the width and amplitude of the signal Then, the signal amplitude counting distributions under different signal width for aerosol´s scattering pulse and the signal width counting distributions under different signal amplitude for background noise of the optical sensor are statistical analyzed by using the optical particle counter. The experimental results show that the counting distributions of amplitude and width subsets for the random pulse signals match well with the form of the lognormal distribution while the natural number as the independent variable. In further, the calculating results indicate that the distributions of the amplitude and width own nonlinear transform relation, under the field of definitions of them for pulse signal That is, there is the non-integer dimension fractal character between the amplitude and width counting distributions.