An integrating sphere to measure CD from difficult samples

Integrating spheres are widely used with UV-Vis and occasionally with infrared spectrophotometers to measure different types of samples, either in transmission mode (scattered transmission accessories) or in total/diffuse reflectance mode. We built a prototype sphere of the demountable type, which fits easily the sample compartment of a commercial CD spectropolarimeter, requiring neither any alignment nor the use of a dedicated photomultiplier. Samples can be inserted either at the sphere entrance (for scattered transmission mode) or in the center of the sphere (for total reflectance experiments). Selected experimental data are presented to evaluate sphere efficiency, its wavelength range and results with a single sample in different forms. Copyright 2000 Wiley-Liss, Inc.