Online Measurement Of Turbidity And Total Biomass: BioPAT® Fundalux

BioPAT® Fundalux is an absorption-based photometric probe that uses light from 840 nm to 910 nm (NIR) to measure the turbidity in bioreactors and fermenters. A precisely defined and constant LED light beam passes through the  process medium from either side of the gap on the probe’s shaft. Its hermetically sealed photodiode detects attenuation of light intensity, which is caused when light is absorbed by cellular mass, dissolved compounds and insoluble material. The 180° constant direct beam optical path lengths (OPL) allow maximum utilization of LED light intensity. The changes in detected light intensity are caused by different degrees of absorption by materials in the medium, which is described by the Beer-Lambert law. This states that the logarithm of the transmission loss is proportional to the concentration of a substance. In addition, as BioPAT® Fundalux operates according to the transmittance principle in the NIR range, it is not affected by color changes in the cultivation medium. As a result, the probe measures the concentration of total biomass accurately and constantly throughout a process based on the respective medium properties.