Anaerobic degradation processes take place in the absence of oxygen. A septum sealed bottle nozzle fills the head space above the sample with inert gas. When anaerobic degradation has taken place, the dissolved CO2 can be driven off and then removed from the head space by means of a CO2 absorber. The resulting pressure difference is proportional to the CO2 concentration; the remaining overpressure is proportional to the methane concentration.

The degradation process can be conveniently observed in the “pressure” operating mode.

The use of special measuring bottles with a septum sealed nozzle allows the interference-free addition of substrates and solutions.

Pressure alterations could indicate a reduction in oxygen concentration, which could necessitate the addition of oxygen, air, or other gases. It is possible to set a “warning pressure” or a pressure limit so adjustments can be made.

The momentary pressure can be stored so the adjustments are fully documented. The recording of these measured values (max. 10 values) permits long-term measurement.