Correlation of Various RI Meters and Reading Comparison of RI Meter Operators on a 735-kV Line

This paper describes the results of a study, sponsored by Working Group No. 1 of the RI Subcommittee, on Hydro Quebec's 735-kV line. Various RI measuring techniques were used in obtaining frequency-spectrum and lateral profiles. Radio noise measuring locations were studied and compared with measuring practices for determining statistical RI levels of operating EHV lines. Comparison between different RI meters has indicated that in the broadcast band the Stoddart NM20B reads 1 to 3 dB higher than the Siemens. An RI measuring test among 14 meter operators indicated the "human" error to be plus or minus 2 dB. Nighttime visual corona was observed and discussed.