Slit Function Research Articles

The Influence of Slit-Width on the Shape and Intensity of Infra-Red Absorption Bands

Making certain assumptions as to the shape of infra-red absorption bands and the shape of the slit function of the monochromator, expressions are obtained for the dependence on spectrometer slit-width of the intensity and half-width of absorption bands. Experimental data to confirm the accuracy of these deductions are presented.

Slit-Width Effects in Spectrophotometry

A technique is suggested which allows an estimate to be made of the errors introduced into spectrophotometric measurements by the use of slits of finite width. The technique depends upon approximate analytic expressions for the slit function, the variation of the instrument sensitivity with wave-length, and the variation of the absorption coefficient with wave-length. A slit function is suggested for use with spectrophotometers with entrance and exit slits of equal width but with optics of varying dispersion. Expressions are derived for two convenient approximations for the absorption coefficient in the neighborhood of a maximum: a parabolic form, and two intersecting straight lines of opposite slope. Application of these expressions is made to experimental data on solutions of benzene, oxyhemoglobin, and neodymium chloride.