AAT Bioquest

What are the applications of transmittance?

Posted December 15, 2022


There are various applications of transmittance. These applications include: measuring concentrations of chemicals in solutions, atmospheric haze, water clarity, and grade of syrup. For measuring transmittance of chemicals in solution, the transmittance formula T= i0/i is used. A spectrophotometer is used in order to measure the ratio between the light which exits and the light that enters the sample. For water clarity, UV transmittance is used to measure the amount of UV light at 254 nm that is able to pass through 10 nm of water. The amount of light that passes through the water sample indicates the water quality. For grading syrup, color is the main factor that indicates the grade; the grade of syrup is confirmed by the percent light transmission. Golden syrup has a light transmission of 75% and above. Amber syrup has a light transmission between 50-74.9%. Dark syrup has a light transmission between 25-49.9%. Very dark syrup has light transmission between 25-49.9%. Thus, the lower the transmission, the darker the syrup is graded. In the automobile manufacturing industry, a light transmittance meter is used to detect the glass transmittance of cars. More specifically, it helps to test the window tint films and glass clarity. Transmittance is important in the use of electro-optical interconnects; adhesives used must have a high transmittance in the spectral region of interest.

Additional resources

Standardization in Transmission Spectrophotometry in the Visible and Ultraviolet Spectral Region