A.DL/T596-2006B.GB50150-2016C.IEC61869D.BS 767
A.0.1%B.0.2%C.0.5%D.1%
A.RA=(RAB+RBC+RCA )/2B.RA=(RAB -RBC+RCA)/2C.R=(RAB+RBC -RCA)/2D.RA=(RAB-RBC-RcA)/2