I am designing a light filter made of PC with pigment designed to filter a range of wavelengths. It is placed very close to the light source and I would like to measure the change in dimensions of the part as well as the projected light passing through the filter.

Other than measuring the dimensions including the length, thickness, and flatness of the lens, are there any suggestions on which measurements I need to take? Also any suggestions on standards/regulations (e.g. ASTM, ISO) would be appreciated.