Measuring the light transmittance and optical density values of Polyimide films is necessary. It is recommended to use Linshang LS117 densitometer for the measurement of Polyimide film light transmittance. LS117 densitometer use diffuse transmission principle, which is very suitable for measuring frosted materials, opalescent and translucent materials. The instrument conforms to the CIE photopic function standard. http://www.shunxuan-pi.com/biaxial-oriented-polyimide-film/