Directive 2010/75/EU of the European Parliament and of the CouncilShow full title
Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010 on industrial emissions (integrated pollution prevention and control) (Recast) (Text with EEA relevance)
2.4.The continuous measurement of the water vapour content shall not be required if the sampled waste gas is dried before the emissions are analysed.