DUAL LUMINOUS FLUX PHOTOELECTRIC PHOTOMETER

PURPOSE:To reduce an error of measurement when two photoelectric detectors are used by providing a converging means on the path of each separated piece of polarized luminous flux, and allowing luminous flux with small sectional area to strike the photodetection surfaces of the photodetectors. CONSTITUTION:A light beam emitted from a light source 1 is converged by a lens 2 and transmitted through a sample 3. The transmitted light enters a spectroscope 5 through a projection slit 6, and a desired wavelength beam is selected and emitted from a projection slit 6. This monochromatic light enters a Wollaston polarizing prism 7 to be separated into a couple of polarized components, but a lens 8 is used for improving the separation efficiency of light with this light velocity to form an image of the projection slit 6 on the reflecting surface of a right-angled prism reflecting mirror 9. Further, lenses 18 and 19 are arragned between the reflecting mirror 9 and photoelectric detectors 10 and 11 and the image of the projection slit 6 formed by the lens 8 on the reflecting surface is formed on the photodetection surfaces of the photoelectric detectors 10 and 11. Thus, the luminous flux is reduced in area and detected on the high- sensitivity photodetection surfaces, so an error of measurement is reduced.