Respirable crystalline silica (RCS) is an inhalation health hazard for mining and industrial work environments and must be monitored. We provide theoretical analysis of real-time measurements for determining RCS mass concentration without the use of filters by using photoacoustic spectroscopy. The suspended dust in the mine air can be continuously sampled by the photoacoustic instrument. A tunable quantum cascade laser is the light source, allowing for determination of interferences such as kaolinite, coal dust, and water vapor. The most useful spectral region is found to be between 11 and 13 μm. Absorption by water vapor, and, to a lesser extent, carbon dioxide, in this spectral region has gaps that allow for quantification of the aforementioned dust species as well as a convenient check on the calibration of the instrument. This work brings photoacoustic measurement of aerosol to the mid infrared range where spectrally dependent light absorption can be used to quantify dust composition and mass concentration.

可吸入结晶二氧化硅 (RCS) 对采矿和工业工作环境具有吸入性健康危害，必须加以监测。我们提供了实时测量的理论分析，用于通过使用光声光谱在不使用过滤器的情况下确定 RCS 质量浓度。矿井空气中的悬浮粉尘可以通过光声仪器连续采样。可调谐量子级联激光器是光源，可用于测定高岭石、煤尘和水蒸气等干扰。发现最有用的光谱区域在 11 和 13 μm 之间。在这个光谱区域被水蒸气吸收，在较小程度上被二氧化碳吸收，这些间隙允许对上述灰尘种类进行量化，并方便地检查仪器的校准。