Table
Ground Resistance Test Methods Comparison
Ground Resistance Test Methods Comparison reference with assumptions and boundary notes.
Reference boundary
Test-method comparison only. It does not set pass/fail targets, replace instrument instructions, or determine grounding system acceptance.
Reference table
Compare common ground-resistance test methods by setup, auxiliary-stake need, and practical limitation.
| Method | Typical use | Auxiliary stakes? | Limitation |
|---|---|---|---|
| Fall-of-potential | Dedicated electrode or grounding system testing | Yes | Needs space and probe placement review |
| 62 percent check | Simplified fall-of-potential spot check | Yes | Soil conditions and electrode geometry can invalidate the shortcut |
| Clamp-on | Multi-grounded systems where the electrode loop exists | No | Not suitable for isolated electrodes without a return path |
| Selective clamp | Testing one electrode in an interconnected system | Usually | Lead placement and parallel paths affect readings |
Use notes
- Use this table for preliminary reference and arithmetic checks only.
- Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.