Research Of Processing Technology About Weak Light Scattering Signal

The weak light scattering signals can reflect the feature information of object that has been widely used in physics,chemistry,aerospace,biomedicine,geology,food and other fields.From the aspect of shape and size detected and the changing signals resulted by the moving inside component of the object,the weak light scattering signals can be divided into two kinds.Both detection and processing methods are different too.In this paper,we mainly study these two types of weak light scattering signals and the different processing techniques respectively to obtain the feature of object.This paper is divided into three parts:In the first part,the purpose,significance and research status of weak light scattering signals are introduced.Secondly,the theory of lock-in amplification algorithm for weak light scattering signal processing is analyzed.Finally,the theory of dynamic light scattering is studied.In the second part,the lock-in amplification algorithm is introduced into processing of multi-channel weak static light scattering spectral data.The parameters of the lock-in amplification algorithm are corresponded with the experimentally obtained weak light scattering signals(spectral data of each wavelength).The multi-channel and multi-dimensional data of lock-in amplification algorithm program is compiled to deal with weak spectral data.The original spectral curve is compared with that of after the algorithm processing.It can be seen that the lock-in amplification algorithm has obvious curve smoothing in the feature spectral band of 720 nm-726 nm,that the noise removal effect is obvious without loss of feature information.In the third part,a double polarization orthogonal dynamic light scattering system is set up to improve the measurement precision with the cross-correlation function.For polystyrene latex particles do Brownian motion in the liquid,the system is used to obtain the weak light scattering signal.The particle size of the sample is 150.1 nm.The error is 16.5% compared with the average particle size of 128.8 nm measured by SEM image.The kind of detection idea improves the precision of the traditional dynamic light scattering measurement in the same experimental conditions.