可变流量PM_(2.5)/PM_(10)切割器校准装置的研制

Development of Calibration Equipment for PM_(2.5)/PM_(10)Separators with Variable Flow Rates

针对颗粒物监测中使用日益广泛的小流量切割器缺乏量值溯源的问题,对可变流量切割器校准装置开展研究,通过设计多种不同参数的发生喷嘴并结合旋风式混匀和等速分流抽/补气等技术,解决了工作流量变化时制约切割器校准的多个技术难点,研制了1台可变流量PM_(2.5)/PM_(10)切割器校准装置,实现了对工作流量为(1~16.7)L/min切割器的切割特性校准。测量过程中通过切割器的气体流量与工作流量的偏差不超过±1%,Da50校准结果的扩展不确定度优于3%(k=2),可满足国内外相应标准的要求。

The widespread use of low-flow-rate separators in particulate matter monitoring has highlighted a need for traceable calibration.This study focuses on developing calibration equipment for variable flow rate separators.By designing various aerosol atomizing nozzles and incorporating cyclone mixing and isokinetic sampling techniques,the calibration equipment was developed for PM_(2.5)/PM_(10)separators operating at flow rates ranging from 1 to 16.7 L/min.The equipment addresses several technical challenges associated with flow rate variations during calibration.The deviation between the actual and working flow rates is within±1%,and the expanded uncertainty of the Da50 calibration results is better than 3%(k=2),meeting both domestic and international standards.