Exploratory research into a NOx test for the periodic inspection of diesel vehicles

TNO has carried out an exploratory study on behalf of the Ministry of Infrastructure and Water management into the effectiveness and applicability of a short emissions test to check the functioning of the SCR catalyst during the Periodic Technical Inspection of diesel cars. The result of the research is that a hot idle NOx test can be used to determine that an SCR catalyst no longer works at all. To sufficiently warm up the catalyst, a few minutes' drive on the road is required prior to the test.