Air quality monitoring: Ineris and LNE join forces to certify sensor systems 10th September 2020 On 31 July 2020, the National Laboratory of Metrology and Testing (LNE, Laboratoire national de métrologie et d’essais) created the “Environmental Instrumentation Certification” (CIE, Certification Instrumentation pour l’Environnement) association in order to establish a certification of sensor systems for measuring air quality. Air quality is a major health issue. Indeed, exposure to ambient fine particles (aerosols) caused more than 4 million premature deaths worldwide in 2016 (WHO 2018). Local authorities and citizens are increasingly demanding information on air pollution levels in real time and on an ever finer scale. In this context, a multitude of sensor systems have been widely developed and put forward to meet this need.