MEASUREMENT OF OPTICAL DENSITY

摘要

Method and apparatus for determining the optical density for radiation within a predetermined range of wavelengths in which a first signal is produced related to the attenuation of radiation over a known path length in the fluid, a second signal is produced related to the attenuation of the radiation over the same path length by solid matter suspended in the fluid and the second signal is utilized to correct the first signal for the presence of the suspended solid matter in the fluid.