Real-time online absorption detection system

A real-time online absorption detection system comprises a light source (1) entering a first optical path through an optical transmission path, a filter (3) arranged along the first optical path, a polarizer (4), a beam transformation unit (5), a beam splitter (6), a sample unit (7), a first detector (9) and a second detector (8) arranged along a second optical path. The first optical path and the second optical path are separated at the beam splitter, and the system also comprises a control module (10), coupled and in communication with the first detector and the second detector for obtaining the absorption rate of test samples waiting to be measured in the sample unit, wherein the polarizer allows the maximum polarization component of a light beam from the light source to pass through, thus increasing the incidental light intensity of the first detector and the second detector. The system combines the light source and the filter to select a measuring beam with a specific wavelength, and has a lower cost when compared with the traditional absorption detection system combining continuous light source with grating to select a measuring beam.