The importance of an inline determination of the UV-curing degree during production increases. Practical offline techniques like i.e. the acetone rub test are in use to ensure a sufficient production process. The scientific crosslink between these test results and the actual polymerization degree is hardly given. This study shows a validated crosslink between established laboratory NIR analysis and UVVIS readings. In conclusion it is shown that for practical application all necessary data can be acquired with industrial inline VIS spectral photometers.