Abstract :
THE automatic oscillograph has been available for about 7 years,1,2 but until 8-cycle oil switches and l-to-6-cycle relays were in general use, the automatic oscillograph was not used extensively because the performance of the slower relays and switches could be checked at low cost by various forms of high-speed graphic meters. With the present high-speed relays and oil switches, the automatic oscillograph is considered almost a necessity.