| Abstract:NH3 throughput rate calculating method improvement work was taken place by taken urea crystals, side reactions, NOx concentration deviation and volatility between upstream and downstream in selective catalytic reduction (SCR) system into account. Emission tests with different AdBlue supply ratio in steady operating condition were taken on engine test bench and the error of this calculating method was confirmed by the analyzing of test equipment, test conditions and data processing methods. The uncertainty in choosing maximum and minimum value of NOx concentration downstream has the most effect of NH3 storage calculation, may lead to an error of more than 20%, but can be optimized by criterion that the amount of NH3 storage is consistent with the NH3 consumption. The uncertainty of NH3 storage starting time and NH3 consume starting time can lead to an error of more than 2.75% in NH3 storage calculation and it is inevitable. While the filtering process and response time of measuring equipment mainly affects the NH3 throughput rate when NH3 storage state change instantly, but the influence on the average rate is quite small. |