In materials research there is sometimes a need to scan high absorbance samples such as laser protection lenses, optical filters, and polarization materials. Such sample types often need to be measured across the whole UV, Vis and NIR ranges of the electromagnetic spectrum. Accurate high absorbance scanning requires a high performance UV/Vis/NIR spectrophotometer with double grating and double monochromator. The stray light level of a spectrophotometer is key to high absorbance scanning and is determined by the quality of the instrument gratings.
This application note describes the procedure for high absorbance scanning with the reference grade PerkinElmer LAMBDA™ 850+ UV/Vis and LAMBDA 1050+ UV/Vis/NIR double monochromator spectrophotometers.