Abstract: A particle sorting and analyzing apparatus operating on the Coulter prince, with two chambers containing an electrolyte which is caused to flow through an orifice connecting the two chambers. The particles to be analyzed are introduced into the first chamber just ahead of the orifice. An electric field is established in the electrolyte by two electrodes, located in the first and second chamber, respectively. After passing out of the second chamber through an atomizing nozzle, selected droplets containing particles are charged and then deflected. The electrical currents generated by the charging processes are kept from interacting with the measuring currents by a third electrode, located in the second chamber in the vicinity of the nozzle and kept at the same potential as the other electrode in the second chamber. The third electrode effectively short-circuits the current path in the second chamber and grounds out spurious electrical disturbances.