A photometric apparatus includes a light source, apparatus for oscillating a light beam spot across a sample, apparatus for measuring secondary light from the sample, and apparatus for determining the specific portion of the sample to be examined by photometry. With this photometric apparatus, each of...http://www.google.com/patents/US4705403?utm_source=gb-gplus-sharePatent US4705403 - Apparatus and method for measuring a photometric characteristic of a sample portion
