Selective catalytic reduction systems, which are more and more often used in exhaust aftertreament systems, require advanced testing and validation methods. Optimisation of the AdBlue dosing strategy depending on the exhaust temperature and the level of SCR reactor saturation requires detailed testing of the nitric oxide reduction efficiency and any possible ammonia emissions (so called ammonia slip).

Other types of tests include evaluation of the precipitation of solid deposits in the exhaust system and visual inspections using a videoscope. The heterogeneity of the decomposition of AdBlue on the surface of the reactor can be determined by means of automated sampling probe measurements.