CONCENTRATION MEASURING APPARATUS

PROBLEM TO BE SOLVED: To provide a concnetration measuring apparatus by which the concentration of a turbid component in a solution to be measured can be measured with high accuracy and with high sensitivity, even when the color of the turbid component in the solution to be measured is changed while the advantage of a concentration measurement by the reflection system of a laser beam is being utilized. SOLUTION: In the apparatus, the concnetration of the turbid component in the solution to be measured is measured by detecting the reflected light of the laser beam emitted toward the solution to be measured. In the concentration measuring apparatus, a plurality of light-emitting optical fibers and a plurality of light-receiving optical fibers are bundled respectively, concentration- sensor faces are constituted on their tips, a plurality of separate receiving- receiving optical fibers are arranged near the concentration-sensor faces, scattered-light-sensor faces which receive scattered light from the solution to be measured are constituted, and a signal processing means by which light- receiving signals by the concentration-sensor faces are compensated by using light-receiving signals by the scattered-light-sensor faces is installed.