高透光率液体吸收系数测量

Measurement of Absorption Coefficient of High Transmittance Liquid

【目的】研究光在高透光率液体中的传输和吸收,设计一个高透光率液体吸收系数的测量装置。【方法】在分析双光束分光光度计测量纯水吸收系数产生误差原因的基础上,依据朗伯定律,设计一种通过测量平行光束经不同厚度待测液体后的透射光照度,从而计算出液体的光吸收系数的装置。用该装置测量纯水的光吸收系数,并将本研究结果与文献报道的积分腔法测量结果进行比较。【结果与结论】用双光束分光光度计测量高透光率液体的光吸收系数时,会受到样品池与液体界面的反射影响而产生较大的误差;用新设计装置测量待测液体的光吸收系数,可消除界面反射影响,得到较准确的结果;该装置测量纯水所得结果与文献报道的积分腔法测量结果基本一致,比国标法测量结果更准确。

【Objective】 To study the transmission and absorption of light in high transmittance liquid and design a device for measuring the light absorption coefficient of high transmittance liquid.【Method】 Based on the analysis of the causes of errors in the measurement of pure water absorption coefficient by double beam spectrophotometer, according to Lambert law, a new device is designed to measure the light absorption coefficient of the liquid by measuring the transmitted light illuminance of the parallel beam passing through the liquid with different thickness;The optical absorption coefficient of pure water was measured by this device, and the results were compared with those reported by the integral cavity method. 【Results and Conclusion】 The light absorption coefficient of high transmittance liquid measured with double beam spectrophotometer will be affected by the interface reflection between the sample cell and the liquid, resulting in large error;while the results measured with the new device, which can eliminate the influence of interface reflection, are more accurate;The light absorption coefficient results of pure water measured by the new device are basically consistent with the results of integral cavity method reported in the literature, and are more accurate than the results measured by national standard method.