Investigation on Sampling Flow Rate Calibration Method of Air Sampler

In order to obtain the most accurate and effective sampling flow rate calibration method of air sampler, several different equipments were used under two different installation conditions in this paper.According to the experimental results, the calibration results of ultrasonic flowmeter and special orifice flowmeter will be affected by the installation conditions.Consequently, while ultrasonic flowmeter and special orifice flowmeter are used to sampling flow rate calibration, it is necessary to first calibrate the two flowmeters with filter paper, and then use the corrected results to calibrate the sampling flow rate.Based on the results of further experiments, calibration datas of gas roots flowmeter and special orifice flowmeter are consistent with the results obtained from gas flow standard facilities by negative pressure method, at the same time, there is still an error of 3%~5% when corrected ultrasonic flowmeter is used.Therefore, gas flow standard facilities by negative pressure method and gas roots flowmeter can be directly used for sampling flow rate calibration of air sampler, if it is not convenient , special orifice flowmeter which calibrated with filter paper is also a good choice, ultrasonic flowmeter is not recommended.