Common beam aperture for dual beam spectrophotometers

摘要

Apparatus compensating for "aperturing effects" produced when a sample holding aperture is incorporated in the sample beam of a conventional dual beam spectrophotometer to allow examination of very small size samples. Such effects usually take the form of undesired variations in the base line output of the spectrophotometer at wavelengths where the spectrophotometer slits open wider than the sample aperture in an attempt to produce a constant energy scan over a given spectrum. The apparatus comprises a second aperture optically equivalent to the sample aperture and located at a slit image point in a common beam portion of the spectrophotometer.