A New Cheaper Dynamic Light Scattering Particle Sizing Method Using Counting Board
Yang Hui, Zheng Gang, Li Meng-chao, Fu Fei-long and Bian Dai-quan
The classical DLS (Dynamic Light Scattering) experiment uses a digital correlator to calculate the ACF (Auto-Correlation Function) and deduces the information of the particle size. Although the commercial digital correlators are readily available and with a higher speed, it usually costs twice that of a Counting Board and on the other hand, the calculating speed is not the point but the accuracy of measurement in the DLS system. In this paper, a new DLS particle sizing method using a Counting Board (M9003) has been developed based on ‘labVIEW’, which reduces the cost of the system dramatically. The pulses from the PMT are counted by a Counting Board at a given sample time. Then, the power spectrum is calculated and the particle size deduced using a characteristic decay constant. The method is systematically tested using small polystyrene latex particles with a wide range of particle concentrations as well as different diameters in suspension.