Measurement of loop impedance in parallel connected grounding networks with a much simpler procedure than possible with conventional processes using two auxiliary earth electrodes

 

Impedance measurement is especially accurate for low values, because inductance present in the loop is taken into consideration during resistance measurement.

 

Touch voltage is estimated by multiplying loop impedance and leakage current. The voltage value ascertained in this way is the maximum value which can occur between the measuring point and earth, because the measured loop impedance value takes the entire loop into account.