ForewordThis guide was written to provide electronics transformer engineers with a standard method for detecting and measuring corona (partial discharge) in electronics transformers. Since there is no simple definition or unit for corona@ it is felt that a guide of this nature will be useful in establishing a common ground of understanding between transformer and systems design engineers and transformer manufacturers in the development of service and performance requirements.This publication was prepared by the Insulation Systems Subcommittee of the Electronics Transformers Technical Committee of the IEEE Power Electronics Society. The Subcommittee membership was as follows:R. A. Frantz@ ChairJ. S. AndreeenC. J. ElliottH. FickenscherP. K. GoetheR. R. GrantH. E. LeeD. N. RatliffR. L. SellB. D. ThackwrayR. M. WozniakWhen the Electronics Transformer Technical Committee approved this guide@ the membership was as follows:H. Fickenscher@ ChairE. D. BelangerC. J. ElliottR. A. FrantzP. K. GoetheJ. SilgailisJ. TardyB. D. ThackwrayR. M. WozniakH. E. LeeW. E. LucarzD. N. RatliffR. L. SellThe following persons were on the balloting committee that approved this standard for submission to the IEEE Standards Board:J. S. AndresenE. D. BelangerR. P. CareyE. J. ElliottH. FickenscherR. A. FrantzP. K. GoetheR. R. GrantO. KiltieL. W. KirkwoodH. E. LeeR. LeeH. W. LordW. LucarzD. RatliffR. L. SellJ. SilgailisJ. TardyB. D. ThackwrayH. I. TillingerR. G. WolpertR. M. WozniakThe final conditions for approval of this guide were met on February 11@ 1991. This guide was conditionally approved by the IEEE Standards Board on September 28@ 1990 with the following membership:Marco W. Migliaro@ ChairJames M. Daly@ Vice ChairAndrew G. Salem@ SecretaryDennis BodsonPaul L. BorrillFletcher J. BuckleyAllen L. ClappStephen R. DillonDonald C. FleckensteinJay Forster*Thomas L. HannanKenneth D. HendrixJohn W. HorchJoseph L. Koepfinger*Irving KolodnyMichael A. LawlerDonald J. LoughryJohn E. May@ Jr.Lawrence V. McCallL. Bruce McClungDonald T. Michael*Stig NilssonRoy T. OishiGay S. RobinsonTerrance R. WhittemoreDonald W. ZipseScopeThis guide covers the detection of corona (partial discharge) and the measurement of its magnitude in electronics transformers. Test conditions@ test apparatus@ calibration@ and test requirements are included.