In spectrophotometry, absorbance ($A$) is logarithmically related to percent transmittance ($\%T$) by the equation:
$$A = -\log_{10}(T) = \log_{10}\left(\frac{100}{\%T}\right) = 2 - \log_{10}(\%T)$$Given $\%T = 75\%$:
$$\log_{10}(75) = \log_{10}(3) + \log_{10}(25) = 0.4771 + 1.3979 = 1.875$$ $$A = 2 - 1.875 = 0.125$$स्पेक्ट्रोफोटोमेट्री में अवशोषणांक ($A$) और प्रतिशत पारगम्यता ($\%T$) का संबंध:
$$A = 2 - \log_{10}(\%T)$$यहाँ $\%T = 75\%$:
$$\log_{10}(75) \approx 1.875$$ $$A = 2 - 1.875 = 0.125$$