Protecting the environment is one of the problems of our century. Many laboratories conduct air testing and monitor industrial emissions to meet environmental standards. Current standards like EN 14181 and ISO 14385 describe the quality assurance procedures for calibration and ongoing quality control ensuring proper operation of automated measuring systems (AMS) to measure emissions of greenhouse gases. Continuous Emission Monitoring (CEMs) operators are familiar with the need to calibrate their analysers using certified calibration gases.