SOME VARIATIONS ON AUTOMATIC SPECTROPHOTOMETERS

Abstract

While modern automatic recording spectrophotometers have been designed primarily to plot transmittance versus wavelength, they can be adapted to a variety of other purposes. An integrating-sphere reflectance attachment has been developed for the Beckman DR which is especially suited for color work. The DR can also be used to follow kinetic reactions by plotting individual transmittance points at any desired time interval, at the command of an external switch, or free running at approximately eight-per-second intervals. It can record energy versus wavelength as well as transmittance. An attachment is being developed to program preselected wavelengths. Measurement is then very rapid for analyses which only require a limited number of points. By connecting a commercial analog-digital converter, cards may be punched for subsequent machine computation. The Beckman DK can record transmittance versus line without modification and can be used to record flame-emission spectra.