The Digital Ground Resistance Tester Model 6471 is a portable measurement instrument designed to measure Ground Resistance with 2 clamps (sold separately), no auxiliary rods, Bond/Connection Resistance (2-Pole and 4-Pole Kelvin sensing), Ground Resistance (3-Pole or 4-Pole), Ground Coupling Resistance, and Selective Ground Resistance, Soil Resistivity (Wenner or Schlumberger method).