Light from a Tungsten lamp (7) is precisely defined by the optics module (6), passes through a window (2), and then through the process stream (1). Light scattered from particles (suspended solids, undissolved liquids or gas bubbles) in the process stream is focused by the scatter optics (3) and detected by eight hermetically sealed silicon photo diodes set at an angle of 11° (5).
Simultaneously, the direct transmitted light is measured is detected by a reference photo diode at an angle of 0° (4). The differential photocurrent induced is directly proportional to the concentration of particles in the stream.
The resulting photocurrents are precisely amplified, converted, and analyzed by the converter. The converter provides real time measurements and can send outputs to the process control system.
