Why do I need to use a Gas Mixing Chamber in my metabolic study?

In order to measure the metabolic parameters VO2 and VCO2, it is necessary  to accurately determine the concentrations of Oxygen and Carbon Dioxide in expired air samples. A gas mixing chamber is necessary to overcome any breath-by-breath and intra-breath fluctuations in these gasses.
The ADInstruments Exercise Physiology System is supplied with a Gas Mixing Chamber to ensure that expired gases are thoroughly mixed prior to being sampled by the Gas Analyser.  These are used during exercise studies to determine metabolic parameters.

Should it be necessary to look at intra-breath variation in O2 and CO2 concentrations, it is possible to sample directly from a face mask or tubing adaptor.