ISO 11771:2010 specifies a generic method for the determination and the reporting of time-averaged mass emissions from a specific installation or of a family of installations (or common source type), using data collected by measurements, and by establishing: mass emission rates by the simultaneous measurement of concentration and gas flow, using standardized manual or automatic methods, and also the estimation of the uncertainty of the measurements; time-averaged mass emission rates using time series of mass emission rate values, their uncertainty characteristics, and also the determination of the expanded uncertainty of the average; time-averaged emission