Amplifier oscillograph has many applications

IN 2 papers, “Amplifiers for Precise Oscillographic Measurements” (Journal of the Franklin Institute, v. 213, June 1932, p. 605–22) and 4 The Amplifier-Oscillograph Applied to the Study of Dielectrics With Continuous Potentials” (Physics, v. 3, July 1932, p. 1–10) Sigmund K. Waldorf, research associate, The Johns Hopkins University, Baltimore, Md., describes the design and construction of the amplifier oscillograph and outlines results obtained in one of its applications. The many interesting applications of this device have included studies of: high voltage wave forms, parasitical corona on high voltage systems, wave forms of magnetic flux in the air gap of an a-c galvanometer, and a-c ionization and d-c charge and discharge currents in insulating materials. In the belief that the device and its uses may be of some possible interest to readers of Electrical Engineering, brief abstracts of the 2 papers are presented herewith.