工作场所空气中总粉尘浓度测定结果不确定度分析

Uncertainty in Determining Total Dust Concentration in the Air at Workplaces

目的对工作场所空气中总粉尘浓度测定结果不确定度进行分析,找出实验过程中对结果准确性影响较大的环节。方法采用国家标准GBZ/T192.1-2007和JJF1059-1999的方法,对某饮料有限公司原料投料岗位总粉尘浓度测定结果不确定度进行评定。结果扩展不确定度为U=0.81mg/m3,Veff=100,P=95%;总粉尘浓度测定结果为(1.1±0.81)mg/m3。在粉尘测定过程中样品质量测量引入的不确定度分量在各个不确定度分量中贡献最大,是影响不确定度的主要因素。结论原料投料岗位总粉尘浓度测定结果符合GBZ2.1-2007的规定;在粉尘测定过程中应严格按照标准分析方法控制实验条件,减少系统效应特别是电子天平称量和空气湿度影响导致的不确定度,对于保证实验测定结果的准确性尤为重要。

[Objective]To evaluate the uncertainty in determining total dust concentration at workplace,and find out the critical impacts of experiment on the accuracy of the results.[Methods]National standards of GBZ/T 192.1-2007and JJF 1059-1999 were adopted to evaluate the uncertainty in determining total dust concentration at the post of material adding in a beverage company limited.[Results]The expended uncertainty was U=0.81 mg/m3,Veff=100,P=95%;the result of total dust concentration was （1.1±0.81） mg/m3.The most critical impact during the measurement process on each uncertainty weight was found out to be the uncertainty weight introduced when measuring the quality of samples.It was also the most critical influential factor on the uncertainty.[Conclusion]The measurement results of total dust concentration at the material input section match well with GBZ 2.1-2007.During the measurement process,it is especially important to strictly abide by standardized analysis method to control the experimental conditions and reduce the systematic effects such as electronic balance and air humidity which may cause adverse impacts on the accuracy of the measurement results.