Laser optical density measurement system

摘要

An apparatus for measuring optical density of highly absorptive materials in which a beam splitter divides light from a laser source into a reference beam, which is directed to a reference detector, and a sample beam, which is reflected off a diffusing plate, through a light limiting aperture, and to a sample. The emanations from the sample are directed to a sample detector. An instrumentation amplifier compares the intensities of the two detectors. The aperture and reference detector are positioned so that the measured intensities are equal, and the optical density of the sample is calculated.