An integrating sphere to measure CD from difficult samples

Integrating spheres are widely used with UV-Vis and occasionally with infra red spectrophotometers to measure different types of samples, either in tra nsmission mode (scattered transmission accessories) or in total/diffuse ref lectance mode. We built a prototype sphere of the demountable type, which f its easily the sample compartment of a commercial CD spectropolarimeter, re quiring neither any alignment nor the use of a dedicated photomultiplier. S amples can be inserted either at the sphere entrance (for scattered transmi ssion mode) or in the center of the sphere (for total reflectance experimen ts). Selected experimental data are presented to evaluate sphere efficiency , its wavelength range and results with a single sample in different forms. (C) 2000 Wiley-Liss, Inc.