Abstract:To establish a method applied to monitoring SO3 acid mist aerosol in high humidity flue gas,the influence of different sampling conditions such as sampling flow rate,water bath temperature,sampling gun temperature,improvement of the device and SO3 concentration on the SO3 acid mist aerosol collection rate are experimentally studied using the SO3 acid mist aerosol generation system and the controlled condensation method.The results show that the most suitable sampling flow rate and water bath temperature are 4 L/min and 70~80℃ respectively,and the sampling gun temperature should be higher than the acid dew point temperature.The addition of the shock absorption bottle has a better improvement effect on the control condensation method.The increase of SO3 concentration leads to a significant decrease in the collection rate of SO3 acid mist aerosol.The monitoring value is corrected by linear regression method to ensure that the error between it and the actual value is within 5%.