PCS颗粒测量技术中软件相关方法的研究

数字相关是PCS颗粒测量技术中的一个关键环节，自相关函数的估计质量直接影响颗粒测量的结果。自相关函数的估计可以通过硬件或软件方法得到。在软件数字相关方法中，利用相关计算时可以得到全部的采样数据这一与硬件相关所不同的特点，能去除采样数据中的均值，并在分析偏差的基础上，采用无偏估计，可有效地提高信噪比，从而获得更好的相关估计值。

The Study on the Estimation of Autocorrelation Function in PCS Particle Sizing Technique

Photon correlation spectroscopy (PCS) is an important technique in particle size analysis, in which autocorrelation function estimation plays a key role. Autocorrelation function can be estimated by two ways, hardware and softwere. The former need the correlator and can do real time processing. The latter, as an off line method, can be completed in program after sampling. Whether used by hardware or software, it is of importance to reduce bias effectively in particle sizing systerm. Based on the character of software correlation, two methords to improve the quality of softwere estimation were discussed:subtracted average from the signal, and adopted non bias estimation.