The publication of the new European Union Basic Safety Standards represents a remarkable milestone in the field of radiological protection in terms of adding radon exposure to this framework. Therefore, the coming years will bring the need to measure radon not only in the workplaces but also in the living spaces as a direct outcome of the application of the new EU Directive. So, the importance of having reliable instruments is evident and interlaboratory exercises are becoming more and more popular. However, most of them are carried out under constant conditions of meteorological variables. We present in this paper a facility to broaden the interlaboratory comparisons further by adding the study of radon exposures under real conditions of changes in climatic parameters. In addition, the facility has the possibility to verify the response of radon monitors when the radon concentration changes several orders of magnitude in a short period of time. Our work shows some results of one of the interlaboratory exercises carried out in the premises, where the radon levels were rather homogeneous in the testing room.
