Portable Grounding Impedance Meter Based on DSP

A new grounding impedance measuring system based on digital signal processor (DSP) platform was developed. The low-cost portable device includes a built-in voltage impulse generator, nonvolatile memory for storage of measured current and voltage waves and a graphical display for fast data visualization. General hardware structure overview and software implementation are discussed. Consistent preliminary field-test results were provided by the measuring system, consisting of records of grounding potential rise and impressed current, impulse impedance, and estimated low-frequency grounding resistance obtained for different electrode arrangements buried in low- and high-resistivity soils.