Real-world NOxemissions from various Non-Road Mobile Machinery and vehicles

In order to gain experience with emission monitoring, TNO equipped a total of 18 mobile machines and vehicles with equipment for measuring NOx emissions. The research shows that the measured NOx emissions are strongly dependent on the power class, the emission class and the presence of a NOx reduction catalyst. The operation of such a catalyst depends on the machine deployment and associated engine load. At moderate to high engine loads, the operation is optimal as a result of the high exhaust gas temperature. At low engine loads, such as idling, the effectiveness of the catalyst decreases significantly, which leads to increased NOx emissions.