A. Chemical Solutions

It is known that some chemicals and salts influence the soil resistivity of the soil and reduce overall earth resistance.

These chemicals are copper sulphate, sodium carbonate, calcium sulphate, sodium chloride (table salt), animal dung and charcoal are sometimes poured into the ground to improve earth readings.

But these have the disadvantages like:

i. Being required in large quantities to make a difference.
ii. Requiring constant moisture to remain effective
iii. Drying out if moisture is not present.
vi. Eventually leaching out of the soil, returning the earth resistivity tto higher value, unless regularly and expensively maintained.
v. Causing corrosion of the earth electrode system and deterioration of concrete (particularly relevant to transmission towers).

B. Chemical Earth Rods

Perforated metal tubes packed with a chemical compound are also sometimes used, but these:

i. Are costly
ii. Are subject to leaching or washing away of the chemicals unless maintained.

C. Bentonite

Its characteristics to absorb and retain moisture around the earth electrode increasing resistivity and reducing Earth resistance.

Makes it invaluable as a conditioning agents with limited applications in the tropics (Africa) with extreme weather condition of dry and rainy season affecting the above characteristics.

However have found applications in temperate regions like Europe and North America with four seasons.

BENTONITE & MARCONITE COMPARED

In practical terms Bentonite and Marconite top the list of conditioning agents. They are now compared