Theoretical resistance in cylindrical electrodes with conical tip

The electrical resistivity method is a well-known geophysical method for observing underground conditions, (such as anomalies) and the properties of soil and rock (such as porosity, saturation, and pore fluid characteristics). The shape of electrodes used in an electrical resistivity survey depends on the purpose of the survey and installation conditions. Most electrodes for field applications are cylindrical for sufficient contact with the ground, while some are conically sharpened at their tips for convenient penetration. Previous study only derived theoretical equations for rod-shaped electrodes with spherical tips. In this study, the theoretical resistance for two cylindrical electrodes with conical tips is derived and verified experimentally. The influence of the penetration depth and tip on the measurement is also discussed.