A fast and easy-to-implement inversion algorithm for mobility particle size spectrometers considering particle number size distribution information outside of the detection range

摘要

Multiple-charge inversion is an essential procedure to convert the rawmobility distributions recorded by mobility particle size spectrometers, suchas the DMPS or SMPS (differential or scanning mobility particle sizers), intotrue particle number size distributions. In this work, we present a fast andeasy-to-implement multiple-charge inversion algorithm with sufficientprecision for atmospheric conditions,but extended functionality. Thealgorithm can incorporate size distribution information from sensors thatmeasure beyond the upper sizing limit of the mobility spectrometer, such asan aerodynamic particle sizer (APS) or an optical particle counter (OPC).This feature can considerably improve the multiple-charge inversion result inthe upper size range of the mobility spectrometer, for example, whensubstantial numbers of coarse particles are present. The program also yieldsa continuous size distribution from both sensors as an output. The algorithmis able to calculate the propagation of measurement errors, such as thosebased on counting statistics, into on the final particle number sizedistribution. As an additional aspect, the algorithm can perform allinversion steps under the assumption of non-spherical particle shape,including constant or size-dependent shape factors.