通过应用对数浓度图，可以得出弱酸或弱碱溶液的ｐＨ值．但是当弱酸或弱碱的浓度非常低时，有必要划一条校正线，此校正线表示ｌｇ（［Ａ＋］＋［ＯＨ－］）的．本文报导了一个用于低至１０－８ｍｏｌ／Ｌ醋酸溶液的具体解法，所得结果与代数法完全一致． By applying a logarithmic concentration graph, the pH of the weak acid or weak base solution can be obtained. However, when the concentration of weak acid or weak base is very low, it is necessary to draw a calibration line, the calibration line that lg ([A +] + [OH-]). This paper reports a specific solution for acetic acid as low as 10-8mol / L, and the results are in good agreement with the algebraic method.