本文提出一种用微电流扩展标尺的全差示光度法,从理论上阐述了微电流放大的原理,标尺扩展与误差的函数关系,不同测量方法的误差比较,最小误差与标尺读数的关系,提出了试液浓度与标尺读数新的对数关系,使校正曲线具有良好的直线性。我们在实验中发现,溶液对比尔定律的偏离,在很大程度上随溶液浓度的增加呈对数变化,同 This paper presents a micro-current extended scale full differential spectrophotometry, theoretically elaborated the principle of micro-current amplification, the function of the scale expansion and error, the difference between different measurement methods, the minimum error and the relationship between the scale reading, A new logarithmic relationship between test solution concentration and scale reading was proposed, which made the calibration curve have good linearity. We found in our experiments that the deviation of the Beer’s law from the solution is logarithmic to that of the solution concentration,