Discussion on ``Electrical Measurements on Circuits Requiring Current and Potential Transformers.'' Frontenac, N. Y., June 30, 1909
Clayton H. Sharp · Transactions of the American Institute of Electrical Engineers · 1909
This important question of the measurement of ratio and phase-angle of transformers is beginning to receive the attention it deserves.I should like to call attention to similar work done at the Electrical Testing Laboratories under my direction by Wm.W. Crawford.By the two-ammeter metho-d of measuring the ratio of cur- rent transformers, it is possible to get quite accurate results, but their accuracy is limited by the steadiness of the available alternating-current supply.It is also desirable that the two instruments should have as nearly as possible the same natural frequency of oscillation.Being dissatisfied with the results obtained by the twoammeter nmethod, we sought a method which would be free from R R= fixed resistance in primary.R'l= variable resistanb'e in secondary./