Electrode types

Rods, tapes, plates, and foundation rebar (ufer) earths are common. Lightning-critical sites often use ring electrodes around structures.

Corrosion & soil

Resistivity and corrosion vary widely between desert sand, clay, and coastal soil. Electrode design and inspection intervals must match the environment.

Measurement caution

A single resistance number is not a complete SPD design. Geometry and bonding often matter more for internal surge voltages.