By using the adapter, the earth resistance measurement of different types of pylon and tower, including Steel Lattice Construction, Steel Tube Construction, Prestressed Concrete and Reinforced Concrete is possible without disconnecting the equipotential bondings. This is particularly useful for lattice towers as there is no need to switch off the line or disconnect the control connections, ensuring the tests are both safe and easy to perform.
Tests of the earthing are performed by wrapping the flexible current sensor around each foot of the pylon. The flexible current sensor also makes it possible to achieve a more accurate result of the earth impedance by making more than one coil around the tower leg. The resistance measurements of each pylon foot can then be used to calculate the overall resistance of the pylon.
The Sonel MRU-200 and Sonel MRU-200-GPS also check the direction of the current when making the measurements. The current direction can help to identify if there is any damage, such as corrosion to the steel strip.
The Sonel MRU-200-GPS also has an integrated GPS receiver to enable the precise location of the pylon tower under test to be stored along with the associated earth resistance measurements .