安德森六级撞击微生物采样器的计量评价及影响因素分析

Influencing Factors Analysis in Quantitative Evaluation of Andersen Six-level Impact Microbial Sampler

由于安德森六级撞击微生物采样器目前缺少相应的标准和检测技术规范,提出了基于捕集效率曲线的空气动力学粒径D_(a50)评价方法,并对D_(a50)的检测与理论计算及其影响因素进行了分析。通过检测5个国产品牌的安德森采样器,发现不同厂家产品测量结果差异较大,多家产品的一级或多级的捕集效率曲线对应的D_(a50)在粒径范围之外。研究发现采样器性能差异并非是由孔径加工精度不够引起,相比之下,不同厂家采样器层与层之间撞击距离有差异,特别是有些厂家的培养基高度可选择范围过宽。研究结果表明:培养基越高,得到的D_(a50)越小;在培养基高度相同情况下,层与层之间距离理想值在10 mm左右。因此,撞击高度是影响安德森六级撞击微生物采样器性能的重要因素。

Due to the lack of standards and detection technical specifications for Andersen six-level impact microbial samplers,an evaluation method based on the capture efficiency curve for the aerodynamic particle size at a sampling physical efficiency of 50%(D_(a50))was proposed,and the detection and theoretical calculation of D_(a50)as well as its influencing factors were analyzed.Five domestic brands of Andersen samplers were tested,and it was found that the measurement results of different manufacturers'products varied significantly,the first or multi-level capture efficiency curves of multiple products corresponded to D_(a50)outside the particle size range.Research has found that the difference in sampler performance is not caused by insufficient aperture processing accuracy.The research results indicate that the higher the culture medium,the smaller the obtained D_(a50),under the same height of the culture medium,the ideal distance between layers is about 10 mm.Therefore,the impact height is an important factor affecting the performance of Andersen six-level impact microbial samplers.