A simple model for transmittance measurements with an integrating sphere is presented. The scattered light is divided into three components, each resulting in its own separate contribution to the detector signal. These contributions depend on the scattering angle and mode of operation. The true specular, diffuse, and total transmittance values are obtained as functions of the signal outputs from a reference reading, a total transmittance reading, and a diffuse transmittance reading. Two different modes of operation are distinguished involving a BaSO4 plate and an Al mirror. Experimental results are presented illustrating the model for two samples with different scattering characteristics.
© 1991 Optical Society of America
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