HIGH-FREQUENCY OSCILLOGRAPHY WITH ELECTROSTATICALLY DEFLECTED INK JETS,

摘要

The report describes a method of forming,charging,and electrostatically deflecting a high-speed jet of small,fluid droplets,and the application of this technique to a high-frequency oscillograph in which the recorded trace is written directly by a jet of ink. The oscillograph combines (1) a frequency response that exceeds that obtainable with mirror-galvanometer systems employing expensive photo-sensitive recording paper,with (2) the instant visibility,contrast,resolution,permanence,and economical operation of moving-pen or -stylus recorders. We have constructed experimental oscillographs that produce traces with amplitudes up to 2cm peak-to-peak; this 2-cm span may be traversed in as little as 10micro sec. The amplitude accuracy of the record is typically =5percent and is limited by spurious deflections of the ink droplets during flight caused by aerodynamic drag and mutual electrostatic repulsion between adjacent charged droplets.