Soil resistivity and soil structure have a huge bearing on the performance of an electrical site’s earthing system or the earth termination components of a lightning protections system. Typical soil resistivity values are available in the technical standards but the range of resistivity provided gives considerable uncertainty in the value that should be used. The best way to ensure accurate project results is to make soil resistivity measurements directly at site, or as close to the area as possible whilst taking account of buried structure interference.

Matthew Taylor (our Managing Director) completed a PhD on Soil Resistivity Measurement and Analysis for Electrical Installations, culminating in recommendations that were written into the latest British Standard (BS EN 50522) so you are in good hands!

Measurements should be conducted to a sufficient depth of investigation and at a sufficient number of test locations to achieve an accurate understanding of the soil resistivity and structure below the site. The information is then analysed to create a soil model, which is an electrical representation of the actual geological conditions and suitable for use in the CDEGS earthing design software or lightning protection calculations. Any supporting technical information, such as borehole records or trial pit data can also be included to enhance the accuracy of the electrical soil model created.

All works is carried out in accordance with the requirements of BS EN 50522.