Precise measurement method was studied to solve the interference of the injection rate measurement from the high frequency wave caused by the previous injection. Based on the Zeuch theory and the principle of micro-perforated plate filtering

the law of shock oscillation in the chamber was investigated

and a measurement chamber with the inner micro perforated plate was proposed. The analysis of three dimensional acoustic field simulation was performed for the proposed measurement chamber. The noise reduction effects from 7000Hz～9000Hz on different plate structure were compared and analyzed. Results showed that the maximum noise reduction capability of the measurement cavity was about 170% of the original device. Simultaneously

the fuel injection rate measurement method with hole plate filter structure was developed. The new approach is able to reduce the high frequency interference shock wave oscillation effectively in measurement chamber for fuel injection rate.