Title :
Ratio Transformer and its Calibration
Author :
Lee, Rae Duk ; Kim, Han Jun ; Semenov, Yu.P.
Author_Institution :
Korea Res. Inst. of Stand. & Sci., Daejeon
Abstract :
A ratio transformer has been developed with currents from internal loading being compensated by means of auxiliary adjustable current sources connected in accordance with a proposed "parallel" equivalent circuit. The compensating currents are injected to section taps of the coaxial screen of a ratio winding. The application of a splitted magnetic system eliminates necessity of magnetic shielding of the transformer. The additional section with double shielding and adjustable potential provides self-calibration with uncertainty about 10-9 . The results of self-calibration have shown that the errors of the decade voltage ratio do not exceed 20 nV/V (in-phase) and 50 nrad (quadrature) at 1 kHz
Keywords :
calibration; equivalent circuits; magnetic shielding; measurement uncertainty; transformers; 1 kHz; auxiliary adjustable current sources; coaxial screen; compensating currents; decade voltage ratio; double shielding; internal loading; magnetic shielding; parallel equivalent circuit; ratio transformer; ratio winding; self calibration; splitted magnetic system; uncertainty; Bridge circuits; Calibration; Capacitors; Coaxial components; Conductors; Equivalent circuits; Frequency; Impedance; Magnetic shielding; Voltage;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 2004 Conference on
Conference_Location :
London
Print_ISBN :
0-7803-8494-6
Electronic_ISBN :
0-7803-8494-6
DOI :
10.1109/CPEM.2004.305623
