Some special oscillograph techniques

The paper gives a general classification of the types of transient phenomena that are of major importance in heavy current engineering, and require oscillographs for their investigation and recording. Such oscillographs are based upon the variety of high-speed tubes now available, and typical performance data are given for some of these tubes, and also for the electromagnetic and continuously evacuated oscillographs that represent the extremes of performance. The particular equipments described include a continuously evacuated oscillograph, high-speed oscillographs with sealed-off tubes, multiple recording on a high-speed drum equipment, a recurrent surge oscillograph, and a recovery voltage indicator. In many applications the oscillograph has to be considered as an integral part of the test circuit, and reference is made to some of the major problems of technique that are involved in such cases.