Short Time Lag of Spark Breakdown

A method involving the use of a series of special electronic voltmeters along an electrical transmission line has been developed to determine the voltages of an incoming surge wave at definite time intervals in relation to another timing wave. By this method, direct readings have been obtained of the time lag of spark breakdown in steps as short as ${10}^{-8\mathrm{}}$ second down to ${10}^{-9\mathrm{}}$ second in some cases. A critical comparison was made of time lag measurements by the dual traveling wave method with measurements by other observers using electro-optical Kerr cell methods. Some corrections of existing results are indicated. The results obtained by the proposed method are in agreement with theoretical considerations.