用于亚微米颗粒测量的后向散射光谱法

针对后向散射光谱粒径测量法对亚微米颗粒测量准确度较差的问题,提出了一种采用紫外光作为光源的测量方法.通过快速傅里叶变换计算了粒径为0.25~1 μm的聚苯乙烯亚微米颗粒的后向散射频谱,将频谱峰值对应的频率值与相应的颗粒粒径进行线性回归,各粒径值相对于回归直线的平均误差为±0.02 μm. 结果表明,本文提出的300~400 nm的紫外光适用于测量0.25~1 μm的亚微米颗粒,相比目前国外最新的采用可见光谱或红外光谱的方法准确度提高了一个数量级,同时该方法也适用于测量双峰分布亚微米颗粒系.

Backscattering Spectroscopy for Sizing Spherical Sub-micron Particles

Optical single backscattering spectroscopy can be used for sizing spherical particles suspended in water, but the accuracy for sizing sub-micron particles cannot be satisfied. To improve the accuracy, the backscattering coefficients between 300~400 nm spectral region is applied to the determination of diameter of calibrated spherical latex polystyrene particles. Through Mie calculations, fast Fourier transform (FFT) and linear regression, the diameters of particles covering the range between 0.25 μm and 1 μm for monomodal particles are determined. The linear regression average error is ±0.02 μm, which is reduced in more than an order of magnitude compared to the data given by the preference. The method can also be applied to bimodal samples.