Holton P M, Willeke K
Department of Environmental Health, University of Cincinnati, OH 45267-0056.
Am Ind Hyg Assoc J. 1987 Oct;48(10):855-60. doi: 10.1080/15298668791385705.
The particle size-dependent leakage into a respirator was examined by measuring the leakage of particle sizes between 0.07 to 4.4 microns through three hole sizes in a negative-pressure half-mask respirator worn by a human subject. This investigation showed that the size distribution of an aerosol test agent and the measurement method have an effect on the leakage measured in a quantitative fit test. For instance, the ratio of percent leakage measured by light scattering between test aerosols with count median diameters of 2.2 and 0.28 microns can be as large at 5:1. Likewise, the ratio of the percent leakage measured by a particle count method vs. a mass method of detection of the same polydisperse aerosol with a count median diameter equal to 2.2 microns can be as high as 4:1. The mass leakage into a mask with a leak is also greater for an exposure aerosol with a count median diameter between 0.15 to 0.30 micron compared to exposure aerosols with larger count median diameters for aerosols with the same mass concentration.
通过测量人类受试者佩戴的负压半面罩呼吸器中0.07至4.4微米粒径颗粒通过三种孔径的泄漏情况，研究了颗粒大小对呼吸器泄漏的影响。该研究表明，气溶胶测试剂的粒径分布和测量方法会对定量适合性测试中测得的泄漏产生影响。例如，计数中位直径为2.2微米和0.28微米的测试气溶胶通过光散射测得的泄漏百分比之比可达5:1。同样，对于计数中位直径等于2.2微米的同一多分散气溶胶，通过颗粒计数法与质量法测得的泄漏百分比之比可高达4:1。对于相同质量浓度的气溶胶，与计数中位直径较大的暴露气溶胶相比，计数中位直径在0.15至0.30微米之间的暴露气溶胶进入有泄漏面罩的质量泄漏也更大。
