ISO 12039:2019 specifies the fundamental structure and the most important performance characteristics of automated measuring systems for carbon monoxide (CO), carbon dioxide (CO₂) and oxygen (O₂) to be used on stationary source emissions. This document describes methods and equipment for the measurement of concentrations of these gases.

The method allows continuous monitoring with permanently installed measuring systems of CO, CO₂ and O₂ emissions. This international standard describes extractive systems and in situ (non-extractive) systems in connection with analysers that operate using, for example, the following principles:

— infrared absorption (CO and CO₂);

— paramagnetism (O₂);

— zirconium oxide (O₂);

— electrochemical cell (O₂);

— tuneable laser spectroscopy (TLS) (CO, CO₂ and O₂).

Other instrumental methods can be used provided they meet the minimum requirements proposed in this document.

Automated measuring systems (AMS) based on the principles above have been used successfully in this application for measuring ranges which are described in Annex G.