US Patent 7641325 Non-conductive fluid droplet characterizing apparatus and method

A fluid droplet characterizing apparatus and method includes a pressurized source of a non-conductive fluid in fluid communication with a nozzle channel and a characterization electrode. The pressurized source is operable to form a jet of the non-conductive fluid through the nozzle channel. At least one portion of the characterization electrode is electrically conductive and contactable with first portion and thereafter a second portion of the non-conductive fluid jet. The at least one electrically conductive portion of the characterization electrode is operable to transfer a first electrical charge to a region of the first portion of the non-conductive fluid jet and transfer a second electrical charge to a region of the second portion of the non-conductive fluid jet.