OPTICAL ABSORPTION MEASUREMENT WITH LIGHT INTEGRATING CAVITY

摘要

Apparatus and method for performing an optical measurement on a flowing target such as a falling stream of water (4). The apparatus comprises detection means (5, 8) arranged to define an optical cavity (6), through which the target flows. Radiation emitting means (7) is arranged for irradiating the target as it flows through the cavity (6). The detection means (8) is arranged to detect radiation emerging from the target in a plurality of directions within the optical cavity (6). The apparatus and method may be used to perform absorption measurements substantially free of scattering effects.