DIN EN ISO 25139:2011-08

Methane (CH₄) is a gas of relevance to the climate and contributes directly to the atmospheric greenhouse effect. After carbon dioxide, greenhouse gas has the second highest anthropogenic influence. Since pre-industrial times methane concentration in the atmosphere has increased by approximately 150 % and the trend is still upward. The emissions of methane originate from natural and anthropogenic sources, whereby the portion from anthropogenic sources is higher. Anthropogenic sources are primarily farm animals, cultivation of rice, extraction and transport of natural gas, landfills, composting plants, gas firing systems and the use of biogas (for instance, sewage plants). Natural sources are wetlands (swamps) worldwide.
The standard specifies a manual method for the determination of concentration of methane emissions from stationary sources. Four sampling options are described. Analysis is carried out using gas chromatography. The method can be applied for both individual measurements and for calibration and validation of automatic CH₄ measuring systems by comparison measurements. The standard of interest to operators of plants emitting CH₄, regulating authorities and measurement institutes.