Measuring bioreactor outgassing

Bioreactor outgassing

Research projects involving isolated chambers with decomposing organic components often use rotameters: the gas is released from the chamber and metered into a gas analyzer (often a mass spectrometer) to determine the actual constituents of the gas.

This diagram demonstrates how an Alicat micro-flow mass meter (MFM) can be used instead of a rotameter, allowing you to achieve substantial improvements in accuracy and automation. The Alicat MFM shown here is calibrated for methane gas. The Bio-Series meter reports the totalized gas flow to the PC, which incorporates this data with the analyzer’s calculations.

Bioreactor Outgassing

Alicat MFM measures flow of outgassed methane from the headspace of the bioreactor into a gas analyzer and sends data to a PC.


The actual gas being released from the bioreactor is not pure methane, but mixture of gases. However, viscosity calculations indicate that the total flow accuracy resulting from this unknown mixture will not exceed ±2% full scale. The MFM’s high operating range of 1–100% and digital communication ability results in a test solution that is highly repeatable with simplified data collection.