Particle Loss Calculator – a new software tool for the assessment of the performance of aerosol inlet systems

摘要

Most aerosol measurements require an inlet system to transport aerosols froma select sampling location to a suitable measurement device through somelength of tubing. Such inlet systems must be optimized to minimize aerosolsampling artifacts and maximize sampling efficiency. In this study weintroduce a new multifunctional software tool (Particle LossCalculator, PLC) that can be used to quickly determine aerosol samplingefficiency and particle transport losses due to passage through arbitrarytubing systems. The software employs relevant empirical and theoreticalrelationships found in established literature and accounts for the mostimportant sampling and transport effects that might be encountered duringdeployment of typical, ground-based ambient aerosol measurements through aconstant-diameter sampling probe. The software treats non-isoaxial andnon-isokinetic aerosol sampling, aerosol diffusion and sedimentation as wellas turbulent inertial deposition and inertial deposition in bends andcontractions of tubing. This software was validated through comparison withexperimentally determined particle losses for several tubing systems bent tocreate various diffusion, sedimentation and inertial deposition properties.As long as the tube geometries are not "too extreme", agreement issatisfactory. We discuss the conclusions of these experiments, thelimitations of the software and present three examples of the use of theParticle Loss Calculator in the field.