Getting Down to Earth 271. Fall-of-potential method, or three-terminal test.2. Dead Earth method (two-point test).3. Clamp-on test method (see Appendix II, page 48). In addition, Megger has developed a version of Fall-of-Potential testing where the operator does not have to disconnect the ground rod under test from the electrical system. The ART (Attached Rod Technique) will be covered in Appendix III, page 54.Fig. 12: Dead earth method or two-point earth resistance testFig.11: Fall-of-potential or three-terminal earth resistance test
