Detecting foam in a bioreactor plant

A system for detecting at least the presence of foam of a medium in of a bioreactor plant, wherein the system comprises:

• a bioreactor plant having at least one single-use container for receiving the medium, that can have the foam, and at least one exhaust port;
• and
• at least two capacitive sensor units, each capacitive sensor unit of the at least two capacitive sensor units being attached at a different situating position of the bioreactor plant, wherein at least one capacitive sensor unit of the at least two capacitive sensor units is arranged:
• (i) at a first situation position in the immediate vicinity of the exhaust port, or
• (ii) at a second situation position on or in spatial proximity to an exhaust hose of the bioreactor system, wherein the exhaust hose is fluidically connected to the exhaust port, or
• (iii) at a third situation at a height below the height of the exhaust port, in particular not in the immediate vicinity of the exhaust port;
• and
• at least one monitoring unit with at least one open-loop and/or closed-loop control unit, wherein the at least one monitoring unit is configured to switch off a mixer and/or a sparging when the sensor unit arranged at the first situation position or the second situation position or the third situation position is triggered,
• wherein the capacitive sensor units each comprise at least one electrode system for a capacitive measurement and can detect the presence of foam at the situating positions on the basis of the capacitive measurement;
• and
• wherein the capacitive sensor units are designed to transmit recorded data concerning the presence of foam to the at least one monitoring unit for monitoring, open-loop control and/or closed-loop control of foam formation in the bioreactor plant based on said data.