Radiocommunication Study Group 6 has approved a number of new Recommendations for international standardization of loudness meters. This has occurred in response to a need by many member administrations for such an instrument or set of instruments. This need has arisen because of a number of recent developments in broadcasting.
ITU-R REPORT BS.2103-1-2008 Referenced Document
ITU-R BS.1770 Algorithms to measure audio programme loudness and true-peak audio level*， 2015-10-01 Update
ITU-R BS.1771 Requirements for loudness and true-peak indicating meters*， 2012-01-01 Update