PM_(2.5)质量浓度分析仪现场校准方法研究  

Study on Field Calibration Method for PM_(2.5) Mass Concentration Analyzer

作　　者：王瑜 吕怡兵[1] 王万里 师耀龙[1] WANG Yu;LYU Yibing;WANG Wanli;SHI Yaolong(State Environmental Protection Key Laboratory of Quality Control in Environmental Monitoring,China National Environmental Monitoring Centre,Beijing 100012,China)

机构地区：[1]中国环境监测总站,国家环境保护环境监测质量控制重点实验室,北京100012

出　　处：《中国环境监测》2025年第1期152-160,共9页Environmental Monitoring in China

基　　金：国家重点研发计划(2022YFC3700404)。

摘　　要：对PM_(2.5)质量浓度分析仪进行准确校准是保证PM_(2.5)质量浓度监测数据质量的重要前提。搭建了一套适用于PM_(2.5)质量浓度分析仪的现场校准方法。该方法基于超声雾化原理,采用氯化钠标准溶液稳定生成不同质量浓度的颗粒物标准物质。测试结果表明:使用该方法发生的颗粒物的粒径符合正态分布,平均粒径为0.6μm;质量浓度相对偏差小于1%,稳定性良好;损失率低,准确度高。为验证校准方法的适用性,采用该方法对量值溯源至手工重量法的基于β射线原理PM_(2.5)质量浓度分析仪分别进行室内和现场长期校准。校准结果显示,PM_(2.5)质量浓度分析仪测量示值与理论浓度值呈线性关系,线性相关系数(R2)均大于0.999。其中:低浓度范围的示值误差小于5μg/m^(3),标准偏差(SD)小于6μg/m^(3);高浓度范围的相对示值误差小于7%,相对标准偏差(RSD)小于5%。以上结果表明,该校准方法的准确性和再现性良好。对校准结果进行不确定度分析发现,PM_(2.5)颗粒物标准物质量值的相对扩展不确定度为2.8%(k=2),PM_(2.5)质量浓度分析仪校准结果的相对扩展不确定度为4.6%(k=2),显著低于手工重量法,表明该方法适用于环境空气PM_(2.5)质量浓度分析仪的实验室与现场校准。Accurate calibration of PM_(2.5)mass concentration analyzer is an important prerequisite to ensure the quality of PM_(2.5)mass concentration monitoring data.In this study,a set of field calibration method suitable for PM_(2.5)mass concentration analyzer was established.Based on the principle of ultrasonic atomization,particulate standard material with different mass concentrations was stably generated by sodium chloride standard solution.The test results showed that the particle size generated by this method conformed to normal distribution,with an average particle size of 0.6μm.The relative deviation of mass concentration was less than 1%,and the stability was good.The loss rate was low and the accuracy was high.To verify the applicability of this calibration method,long-term calibration of PM_(2.5)mass concentration analyzer using the method of quantity traceability to manual weight method ofβray theory was carried out indoor and field respectively.The calibration results showed that their was a linear relationship between the measured value of PM_(2.5)mass concentration analyzer and the theoretical value,R2 were greater than 0.999.In the range of low concentration,the indicating error was less than 5μg/m^(3),and the standard deviation was less than 6μg/m^(3).In the range of high concentration,the relative indicating error was less than 7%,and the relative standard deviation was less than 5%.The accuracy and reproducibility were good.The uncertainty analysis of PM_(2.5)calibration results showed that the relative extended uncertainty of the standard value of PM_(2.5)mass concentration was 2.8%(k=2),and the relative extended uncertainty of the calibration result was 4.6%(k=2),which was significantly lower than the uncertainty of manual gravimetric method,indicating that this method is suitable for laboratory and field calibration of PM_(2.5)mass concentration analyzer in ambient air.

关 键 词：PM_(2.5) 颗粒物标准物质 现场校准 

分 类 号：X830[环境科学与工程—环境工程]