Measuring system for optimising electrical earth connection - balances phases of incident and reflected waves from frequency generator to transmission line connected at earthing point

摘要

The connection is effected by driving a spike into the ground. The spike is connected to the central conductor of a coaxial cable whose outer conductor is not connected. The conductor is connected to a directional coupler and connecting block to an impedance analyser. This generates frequencies over a wide HF range and provides analysis at those frequencies. Alternatively, the conductor can be connected through a second directional coupler to an analyser covering the HF and UHF frequency ranges. The analysers and a tracing table are connected to a processor powered from a battery driven AC power circuit. The processor provides automatic adjustment to balance the phases between cables transmitting the incident and reflected waves to and from the earth spike. The processor determines the graphical points for display on a Smith chart on the tracing table. Earth connections for protection against lightning and em interference may be optimised by this method.