Measurement System of Diameters of Ultrafine Particles Based on Virtual Instrument

The measurement system of diameters of ultrafine particles was developed with virtual instrument. Instead of the much expensive correlator, the photon counting technology was applied: H6240-01, the photon multiplier tube (PMT), was used as a detector; and M8784, the high speed photon counter, was used to count the pulses signals of PMT output, the real-time data of dynamic light scattering were analyzed in the mixed program of MATLAB and LabVIEW. We experimented respectively with the standard polystyrene latex particles: mean diameters of 100 and 600 nm monodisperse and mean diameters of 90 and 450 nm polydisperse, got the autocorrelation function curves of light scattering signals, and the exact information of particle size distributions could be deduced from the inversion results of the autocorrelation function of monodisperse and polydisperse with CONTIN arithmetic.