Arc extinction phenomena in high voltage circuit breakers studied with a cathode ray oscillograp

A MEDIUM-speed cathode-ray oscillograph with a rotating film has been built for the study of circuit breaker transients. The film is wrapped around a drum and rotated in the vacuum at high speed. Each film shows in a continuous trace, a complete story of the formation of arc, subsequent reignitions and final extinction. More than 15 complete cycles may be recorded without excessive blurring. Each film is self-calibrated.