There are basically two types of earth mats or ground mats.
Often in the ground below an outside substation and/or a high voltage test cage, you may find a copper lattice. This is an earth mat and it is generally manufactured from tinned copper tape or hard drawn copper wire and the lattice is completely welded together.
- Lightning protection earth mats are used below sub stations to improve the earthing points whenever burying ground rods is not possible.
- Power cable partial discharge test cages have lattice mats in the concrete or below the concrete. They are there to screen out spurious electrical signals during testing
There are semi-conducting rubber earthing mats perhaps with fine copper wire woven into them so that people can discharge static electricity from their bodies. They plug only into the ground on the electrical system in the home or office.
- In offices, (desk pads, mouse pads), especially for barefoot computer operators.
- At home such as on a chair, couch or bed. It can also be used for pets.
- People out walking may have a grounding contacts on the bottom of their shoes.
- Automobile or truck drivers and passengers. The vehicle may be grounded by a cable and termination dragging at or close behind the rear bumper.
You will have to contact your local Hydro to obtain the conductor size and lattice dimensions for the power applications.
As far as static electricity is concerned, you may have to contact your local government health and safety regulatory commission to obtain the appropriate specifications.
I imagine there are country by country specification for both these applications.
Peter J. Stewart-Hay
Stewart-Hay Associates www.Stewart-Hay.com
519 641- 3212
Hudson Wire in Trenton, GA used to provide very fine copper wire to the carpet industry and it was woven or tufted into the carpet to produce an anti-static product. It was a highly profitable business and had great connections as one of our sales guys had come from the carpet industry. Great idea that faded away when a chemical solution to the problem was developed.