The sparkless sphere gap voltmeter

Discussion and authors´ closure of a paper by R. W. Sorensen, J. E. Hobson, and Simon Ramo, published in the June 1935 issue, pages 651–6, and presented for oral discussion at the selected subjects session of the summer convention, Ithaca, N. Y., June 27, 1935. A. O. Austin (consulting engr., Barberton, Ohio): The authors have carried out a very effective method of checking root mean square values with means at the disposal of practically any high voltage laboratory. Anyone making high voltage measurements is continually running up against conditions upon which it is desired to make a check, and since the method involves no elaborate equipment it can be readily carried out. Where the wave form is good the method may be used for checking crest values. It would seem that the method is primarily applicable for calibration purposes. The capacitance calculations of the sphere gap can also be used very effectively for determining crest voltages which I believe have a wider application than the determination of root mean square values. With the close control of frequency the determination of voltage with an ammeter in series with a capacitor of known capacitance is very simple.