BACKGROUND REDUCTION ACCESSORY FOR INFRARED ABSORPTION SPECTRUM

摘要

PURPOSE:To achieve a higher S/B ratio and S/N ratio of an infrared spectrum of a heterogeneous sample, by using a background reduction accessory of an infrared absorption spectrum comprising a reflector or a prism for trapping infrared scattered rays or reflected light. CONSTITUTION:A sample 3 in the form of a tablet is arranged at a focal position 2 of a reflector 1. The sample 3 is fitted into a central recess of a window material 4. Infrared rays 5 enter the reflector 1 at an incident port 6 to be incident into the sample 3 and transmitted, reflected or scattered. The transmission light is also scattered by the window material 4. The forward scattered infrared rays are also condensed. Outgoing light from the samples is gathered with the reflector 1 and converges on to a detector 9 passing through a flat mirror 7 and a concave mirror 8. The reflector 1 herein used is ellipsoidal mirror or parabolic mirror. The diameter and focal length of the mirrors can be determined simply according to an infrared spectrophotometer.