概要（Overview）

The U-3900/3900H provides aberration-corrected concave gratings with a Seya-Namioka Mount for the spectrometer. Both condensing and dispersing functions allow for a bright optical system, but with fewer mirrors so that light loss and aberrations are reduced. The Double Monochrome (U-3900H) is suitable for a high-concentration sample since it can measure high absorbance with little stray light.