臭氧吸收截面关键参数研究进展

Research development of the key value for ozone absorption cross-section

近期,国际计量局(BIPM)修订臭氧吸收截面的新参数,这是该参数在沿用40余年后的首次变更。修订后的臭氧吸收截面值为1.1329×10^(–17)cm^(2)·molecule^(–1),相对标准不确定度0.31%,相对于现行参数,数值上减小了1.23%,不确定度减小到七分之一。BIPM建议新参数于2024年开始在全球推广使用。臭氧吸收截面系数是当前国内外臭氧量值溯源体系中的关键计量参数,该参数的修订将直接影响臭氧气体浓度的测量值及其不确定度,进而影响全球的臭氧浓度监测结果。我国也同样面临该参数的修订问题,为便于相关工作的推进,该文介绍臭氧吸收截面的研究历程,阐述本次修订的背景和意义,重点讨论气相滴定法与分压法这两种臭氧吸收截面的核心研究方法的原理与技术差异,深入分析这两种方法的技术现状,以期为我国臭氧检测和量值溯源工作的进一步国际化接轨打下坚实基础。

Recently,BIPM has proposed a new value of ozone absorption cross-section(OACS).It is the first time that OACS value,which was used for more than 40 years,was revised.The revised OACS value is 1.1329×10^(–17)cm^(2)·molecule^(–1)with a relative standard uncertainty of 0.31%.Comparing to the current OACS value,the revised one is a little less,namely 1.23%,with a sixfold smaller relative standard uncertainty.BIPM suggests that this new value should be used by all the countries since 2024.OACS value is the key parameter in the current domestic and international ozone metrological traceability system.The revision of OACS value will influence the results and corresponding uncertainties of ozone measurements.Focusing on this important revision,this paper described the research history of OACS as well as the detailed background and significance of this revision.Furthermore,differences in principles and techniques between gas-phase titration and partial pressure methods,which are the basic research methods for the OACS value,are sufficiently discussed.In addition,the technology status of these two methods has been deeply analyzed.Above all,this paper lays the solid foundation for further internationalization of ozone detection and traceability in China.traceability in China.