Abstract

A quantitative fit test is performed using a benchtop instrument (e.g., TSI PortaCount) to assess the fit factor provided by a respirator when assigned to a worker. There are no wearable instruments on the market to measure protection factors while the respirator is in use. The aim of this study is to evaluate two new, wearable, quantitative instruments—a dual-channel optical particle counter (DC OPC) and a dual-channel condensation particle counter (DC CPC)—that would enable in-situ, real-time measurement of respirator workplace protection factor. Respirator laboratory protection factors measured by the new instruments were compared to those measured with the TSI PortaCount on one test subject for three test aerosols (sodium chloride, incense, ambient) at target laboratory protection factors of 100, 300, and 1,000 for sodium chloride and ambient, and 75 and 500 for incense. Three replicates were performed for each test condition. Data were analyzed with a two-sided paired t-test at a significance level of 0.05. Laboratory protection factors measured with the DC CPC agree with those measured with the PortaCount whereas those from the DC OPC generally do not. Mean laboratory protection factors derived from the DC CPC are only statistically significantly different for mean values of a laboratory protection factor at ambient conditions for a target laboratory protection factor of 300 (p = 0.02) and for incense at a target laboratory protection factor of 75 (p = 0.03). Although statistically significant, the difference in laboratory protection factors derived from the DC CPC are not substantial in practice and may be explained by systematic uncertainty. In contrast, the DC OPC reports substantially larger mean laboratory protection factors, differing by about half an order of magnitude in extreme cases, and statistically significantly different mean laboratory protection factors for the sodium chloride aerosol for target laboratory protection factors of 100 and 300 (p = 0.01 and p = 0.01).

摘要

使用台式仪器（例如，TSI PortaCount）执行定量拟合测试，以评估呼吸机分配给工人时提供的拟合因子。在使用呼吸器时，市场上没有可测量保护因素的可穿戴仪器。这项研究的目的是评估两个新的，可穿戴的定量仪器-双通道光学粒子计数器（DC OPC）和双通道凝结粒子计数器（DC CPC）-这些仪器可以实现就地测量，实时测量呼吸器工作场所的保护因子。将新仪器测得的呼吸器实验室保护因子与TSI PortaCount测得的三种测试气雾剂（氯化钠，熏香，环境气体）的TSI PortaCount相比，将氯化钠和氯化钠的目标实验室保护因子分别设为100、300和1,000。常温，香气75和500。对每个测试条件进行三份重复。数据采用0.05的显着性水平的双向配对t检验进行了分析。用DC CPC测量的实验室保护因子与用PortaCount测量的实验室保护因子一致，而使用DC OPC的实验室保护因子通常不同。p  = 0.02），并且对于目标实验室保护系数为75的香（p  = 0.03）。尽管从统计学上来说很重要，但是DC CPC产生的实验室保护因子的差异在实践中并不明显，可以用系统不确定性来解释。相比之下，DC OPC报告的平均实验室保护因子要大得多，在极端情况下相差约半个数量级，对于目标实验室保护因子为100和300（p  = 0.01和p  = 0.01）。