Impulse earthing measurements

Technical information for lightning protection earthing systems and overhead transmission lines.

Earthing under impulse conditions

Lightning currents rise within microseconds. The inductance of buried conductors and wave propagation in an extended earthing arrangement influence the resulting voltage drop.

The impulse method evaluates this behaviour using peak values of current and voltage. ATMOR instruments were developed from research carried out by engineers associated with the Technical University of Gdańsk.

Tests of transmission tower earthings can take account of both the artificial earthing and the tower foundation. The technical paper discusses the effects of neighbouring towers, impulse front time and span length, with computer simulations and field measurements.

Impulse current and voltage drop across an earthing system — Current and voltage waveforms during an impulse test.

Technical documents

Impulse measurement of lightning protection earthing impedances

PDF · research paper in English

WG-407 earthing impulse meter — user manual

PDF · operation, memory and battery charging

The documents contain historical references to standards. Specifications and operating instructions apply to the particular instrument described.

WG-407

Measurement and memory

The WG-407 manual describes automatic measuring ranges of 0–19.9 Ω and 20–199 Ω, a 4.8 V rechargeable battery and memory for 126 measurement results. The instrument provides measurement, memory and battery-test modes.

Its accessories include two measurement stakes, conductors for the current probe (40 m), voltage probe (30 m) and tested earthing (2 m), a cable reel, a bag and a power supply for charging.