NIST Calibration Facility for Sizing Spheres Suspended in Liquids
Michelle K. Donnelly, George Mulholland, Michael R. Winchester
A calibration facility has been developed to measure the peak diameter of particles suspended in liquid using differential mobility analysis (DMA). A description of the facility and the features that contribute to measurements with low uncertainties is included. Analysis of the DMA convolution integral allows correcting for the effects of charging probability, size distribution, and transfer function on the measured peak particle size. Current research using electrospray to aerosolize the particles is aimed at expanding the measurement size interval.