Direct measurement of surge currents

A new instrument, called the surge crest ammeter, based upon the principle of magnetic retentivity has made available a direct and simple method of measuring surge currents. A study of the behavior of 2 magnetic links under the influence of oscillatory surge currents has made this instrument useful in measuring the per cent oscillation as well as crest values of surge currents. Specimen measurements included in this paper show briefly one application of this instrument.