A Charge-Analyzing Probe for Aerosol Flows

A charge-analyzing probe for sampling aerosol flows that has been developed allows the charges and masses of the positively charged, negatively charged, and neutral fractions to be measured. It has been used to characterize the tribo-charge state of fly ash dispersed into a dust tunnel facility used for precipitator research. Bipolar charge/mass (q/m) ratios in the range ±(10-50)?C/g are typically measured, depending on the ash sample and its size distribution. It is shown that large conducting particles can undergo a shuttle motion which leads to anomalously high q/m values.