A new voltage time recorder for transient measurements

ENGINEERING measurements of electric circuit quantities such as voltage, current, power, energy, and wave shapes have, for the steady-state conditions including both non varying quantities and recurring waves, been made with general satisfaction, through steadily improving designs of voltmeters, ammeters, wattmeters, and oscillographs. These are measurements of the quantities directly pertinent to the purposes for which the circuitry was designed. All circuitry, however, is also unintentionally subjected to electric transients when steady-state levels are changed and when abnormal electrifications or connections occur. These are mainly switching, lightning, and insulation failure transients and they involve voltage and current variations where fractions of a microsecond sometimes become important because of the high magnitudes of the voltages and currents involved.