SF6 is a substance which originates only from anthropogenic sources used primarily in the electricity and electronics supply industries, e.g. the semiconductor industry, where it is used as an electronic insulator due to its inertness. SF6 is a trace gas that exists in small quantities at the level of ppt (parts-per-trillion, 1/1012) in the atmosphere, but its global warming potential is 23,500 times greater than that of CO2 when compared over a 100-year period. In particular, SF6 has an atmospheric lifetime of 3,200 years upon emission, and will eventually exacerbate the man-made greenhouse effect in the long term due to its higher radiative forcing, with greater significance in the future rather than in the present. Therefore, the measurement data of SF6 will carry significant importance as basic materials for future discussions on climate change. Since SF6 is a greenhouse gas that exists in trace quantities at 5-15 ppt in the atmosphere, measurement of the gas requires a very precise procedure. This document provides guidelines on how to produce more accurate and precise values in continuous atmospheric SF6 measurements, as well as the discrete sample analysis after collecting the air, preparation of standard gases for laboratory applications, and intercomparison experiments. These guidelines are also helpful to prepare the working standards, which have traceability to laboratory standards considering the scale propagation errors. In this guideline document, WMO scale (NOAA-X2014) is used for the calibrations. The instrument setup and analysis methods refer to WMO (2015).
Collection(s) and Series: GAW Report- No. 239
Format: Digital (Free)