DIFFUSION DEVICE FOR COMPENSATING FOR NON-UNIFORM PHOTOMULTIPLIER CATHODE SENSITIVITY

摘要

A compensation arrangement for a multi-beam spectrophotometer optical system of the type using a photmultiplier tube whose cathode alternately or at different times receives physically space light beams emerging from reference and sample material. The spaced light beams pass through a diffuser plate into a light duct having mirror interior wal?s which interiorly multiply-reflect the emergent rays form the diffuser plate to provide uniform diffusion of the rays in the duct with minimum loss. The exit end of the duct faces the working area of the photomultiplier tube cathode so that this cathode area is uniformly illuminated by the uniformly diffused rays, whereby the response of the photomultiplier tube is not affected by non-uniform sensitivity of different parts of the cathode working area.