Cost-effective BRDF spectroscopic bench involving gimbal-based sample positioning system

This paper addresses the engineering aspects of implementing a cost-effective instrumental approach to measuring the Bidirectional Reflectance Distribution Function (BRDF) of optical diffusers. The measurement bench presented involves a PerkinElmer UV/Vis/NIR spectrophotometer equipped with a sample angular orientation system based on a compact motorized gimbal. This instrumental approach allows for measuring the BRDF with accuracy comparable to that achieved in much more expensive robot-based gonioreflectometer benches. Its practical implementation is straightforward and does not require significant costs for purchasing additional measuring equipment or adapting the
laboratory clean room. The presented approach can be easily adapted to other available spectrophotometers. Additionally, we introduce a relatively simple yet effective data processing method and discuss various aspects of its practical use for analyzing measurement data obtained using the developed spectrometric bench.