Accession Number:

AD0621102

Title:

THE PRECISE MEASUREMENT OF CURRENT RATIOS.

Descriptive Note:

Revised ed.,

Corporate Author:

NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO)

Personal Author(s):

Report Date:

1964-11-02

Pagination or Media Count:

13.0

Abstract:

The development of the current comparator, a threewinding current ratio transformer, is reviewed and its characteristics as an alternating current ratio standard are analyzed. Particular attention is given to the use of magnetic shielding and its effect on the accuracy and usefulness of the device. Some error characteristics of three types of audio-frequency current comparators are given and possible applications discussed. These include the calibration of current transformers and impedance comparisons. The adaptation of this device to dc operation is made possible by modulation techniques. A 20 000-ampere selfbalancing direct current comparator, designed specifically for the calibration in situ of transductors or direct current transformers, is described. The application of this comparator to the calibration of shunts at high currents also is discussed and some results presented. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE