In addition to reporting the wavelength of maximum absorption (max ), chemists often report another quantity that indicates the strength of the absorption, called the molar absorptivity, EIn addition to reporting the wavelength of maximum absorption (λmax ), chemists often report another quantity that indicates the strength of the absorption, called the molar absorptivity, ε Lambert-Beer Rule; A = ε C L = - log I Io A----absorbance 吸 光 度 ε --- molar extinction coefficient 摩 尔 消 光 系 数 C----molar concentration of sample L-------the length (in centimeter) 液 层 厚 度