Reducing Agent Injector -N474-

The injection of the reductant works similarly to the injection of fuel. The SCR dosing valve injects the reductant into the exhaust gas flow upstream of the SCR catalyst. The amount of reductant that is injected is determined by the opening time of the SCR dosing valve. This opening time depends on the temperature of the exhaust gas stream upstream of the SCR catalyst, the exhaust gas flow rate and the engine's NOx emissions.