Standards VDI 4211 and VDI 4212 on passive FTIR and DOAS remote sensing techniques

Passive Fourier Transform Infrared (FTIR) and Differential Optical Absorption Spectroscopy (DOAS) techniques, i.e. those making use of natural radiation sources are used since the 1970s for the remote sensing of trace gases in the atmosphere. Characteristic for these methods is that they can be put to stationary or mobile use (e.g. cars, multicopters, balloons, aircraft, satellites), are capable of very quickly generating indicative data over a large measurement range and permit quantitative determinations of defined substances. A number of distinct method variations has been developed for specific purposes that cover a broad range of applications in emission and ambient air measurements. These reasons prompted the Commission on Air Pollution Prevention of VDI and DIN (a standards committee of the German Standards Institute) to establish the German Standards VDI 4211 and 4212 on these techniques. Both Standards are also intended to support and encourage manufacturers and start-ups to develop and produce marketable instruments in consideration of future air monitoring concepts (small, mobile, versatile, multi-component analysers). In order to pave the way for these methods to be recognized by the authorities as equivalent methods to established air quality monitoring methods experience-based minimum requirements for selected performance characteristics are recommended which may be the basis for a future type testing procedure.