IEEEIEEE 81Guide for Measuring Earth Resistivity, Ground Impedance, and Ground System Potentials.Referenced across 3 Anvilfield field guides. Field guides that apply IEEE 81ElectricalElectricalGround ring electrode field guideElectricalGrounding system testing field guideDatacenterDatacenterGround resistance testing Often cited alongsideNECIEEE 142NFPA 780UL 467 Browse all codes and standards