职业卫生检测中标准气体的配制研究

Preparation of standard gases for the occupational health

目的比较职业卫生日常检测及标准研制领域中常用的标准气体配制方法及其应用效果,尝试将专业标准化标准气体制备手段同有限条件下实验室日常简单标准气体配制技术相结合,保证标准气体制备量值的准确稳定和有效传递。方法使用不同标准物质及不同标准气体配制方法,配制氯乙烯混合标准气体,并对不同方法的配制结果进行检测和评价。结果使用质量流量比动态配气法配制氯乙烯标准气体,该方法的日内精密度为3.8%-5.6%,日间精密度为8.5%-9.6%,合成不确定度〈1.6%。相同稀释比条件下,该方法日间精密度小于注射器配气法;两种配气法的合成不确定度相差不大。结论质量流量比动态配气法稳定性高于注射器配气法。使用将定值标准气体与质量流量比动态配气法相结合的标准气体配制技术,能够保证标准气体配制过程中量值的准确稳定和有效传递。

Objective This article introduced the application of the general methods for preparation of standard gases. Our study aimed to combine professional preparation method of standard gas with daily lab preparation method of comparative samples,to ensure the accuracy and precision of standard gases. Methods Different standard materials and different preparation methods were used to prepare the standard gas of vinyl chloride,and the precision and uncertainty of different methods by using the same detection method of GBZ/T 160.46-2004 was compared. Results The intra-day precision and inter-day precision of the mass flow ratio dynamic volumetric method was 3.79%- 5.64% and 8.54%- 9.63%,respectively. The combined uncertainty of this method is lower than 1.6%. The inter-day precision of the method with same dilution ratio were less than that of the syringe gas distribution method. Conclusion The stability of the mass flow ratio dynamic volumetric method was better than the syringe gas distribution method. The standard gas preparation method combining with the definite value standard gas and mass flow ratio dynamic volumetric method can ensure the standard development process and the data accuracy stability in the process.