The standard curve and regress e-quation was made according to the linear relation of absorption and density, and the result showed that it accorded with the law of Lambert-Beer.

• 用表面活性剂溶液洗涤染色后的头发,测出最大波长处的吸光度,据回归方程计算出各次洗涤液中所含染发剂的浓度,推知其含量,从而预测牢固程度。