The test sample was prepared according to the sampling method described before, and its observation result with the high-resolution microscope are shown in the figure below. It could be clearly seen from the picture that there were many blue circular spots distributed on the surface of the glass slide, and one spot was marked with a black circle whose diameter was 28.83 μm. This proved that the sampling system designed in this project was feasible, which meant the collected droplets were at the micron level. Meanwhile, it was worth noting there were many blue spots with diameter much smaller than 28.83 μm in the sample, and the size of these spots reached the sub-micron level. Therefore, the droplets prepared by the sampling system could accurately simulate most common chemical particles.