SOIL RESISTIVITY / EARTH RESISTANCE MEASUREMENTS

Soil resistivity measurements are made to provide an indication of the soil corrosivity and for use in anode groundbed, attenuation and earthing calculations. 

Soil corrosivity can be classified  as:

• 0 – 10 ohm.m          severely corrosive
• 10 – 50 ohm.m        corrosive
• 50 – 100 ohm.m      moderately corrosive
• > 100 ohm.m           slightly corrosive

The preferred unit of measurement is the ohm metre (not ohms per metre) (ohm.m) although values are often quoted in ohm centimetres (ohm.cm).  To convert ohm.m to ohm.cm multiply by 100.

Barnes Layer Analysis

Corroconsult can provide soil resistivity for both shallow and deep layer assessment as required, and full Barnes Layer Analysis provided for each assessed layer.

Installed System Resistance to Earth

The 3-point method, called the “fall of potential” method, can be used to evaluate the resistance of an installed earthing system or anode groundbed. This information can be utilised to verify that the installed system is compliant with the design requirements.