U.S. Department of Health and Human Services, Public Health Service, Pittsburgh Research Laboratory, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, Pittsburgh, PA, 15236, USA.
Environ Monit Assess. 2020 May 7;192(6):333. doi: 10.1007/s10661-020-8244-z.
NIOSH researchers designed a high-sensitivity (HS) cassette to improve the limit of detection of the National Institute for Occupational Safety and Health's (NIOSH) method 5040 and the Airtec near real-time diesel particulate matter (DPM) monitor. This was achieved by reducing the size of the diesel particulate matter deposition spot from 8.0 cm (NIOSH method 5040 mining samples) and 7.6 cm (Airtec samples) to 0.5 cm. When compared with the standard cassette, the new high-sensitivity cassette improves the limit of detection of NIOSH method 5040 by approximately five times, and the differences between the elemental carbon results from the HS cassette and the standard three-piece cassette were within statistical error. The limit of detection for Airtec measurements improved by approximately 15 times, and the elemental carbon results with the HS cassette between the Airtec and NIOSH method 5040 were within statistical agreement. When used in the Airtec monitor, the high-sensitivity cassette showed promise for measuring short-duration spot checks of ambient concentrations but was limited when performing some long-term sampling due to the resultant loss of dynamic range. Only up to 7 μg of elemental carbon was collected onto the HS cassette before the increase in pump backpressure caused the flow fluctuations to exceed targeted values by unacceptable levels. The HS cassette shows promise for effective engineering evaluations of control technologies and strategies and near real-time diesel particulate matter measurements for a variety of occupations.
美国国家职业安全与健康研究所（NIOSH）的研究人员设计了一种高灵敏度（HS）盒，以提高 NIOSH 方法 5040 和 Airtec 近实时柴油颗粒物（DPM）监测仪的检测极限。这是通过将柴油颗粒物沉积点的尺寸从 8.0 厘米（NIOSH 方法 5040 采矿样本）和 7.6 厘米（Airtec 样本）缩小到 0.5 厘米来实现的。与标准盒相比，新的高灵敏度盒将 NIOSH 方法 5040 的检测极限提高了约五倍，HS 盒和标准三件套盒之间的元素碳结果差异在统计误差范围内。Airtec 测量的检测极限提高了约 15 倍，HS 盒与 NIOSH 方法 5040 之间的元素碳结果在统计上一致。当在 Airtec 监测仪中使用时，高灵敏度盒有望用于测量环境浓度的短期点检查，但由于动态范围的损失，在进行一些长期采样时受到限制。在泵背压增加导致流量波动超过目标值达到不可接受的水平之前，高灵敏度盒上仅收集了多达 7μg 的元素碳。高灵敏度盒有望成为控制技术和策略的有效工程评估以及各种职业的近实时柴油颗粒物测量的有效工具。
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