Electrical resistivity tomography Electrical resistivity tomography Electrical resistivity tomography (ERT) or electrical resistivity imaging (ERI) is a geophysical technique for imaging sub-surface structures from electrical resistivity measurements made at the surface, or by electrodes in one or more boreholes. If the electrodes are suspended in the boreholes, deeper sections can be investigated. It is closely related to the medical imaging technique electrical impedance tomography (EIT), and mathematically is the same inverse problem. In contrast to medical EIT, however, ERT is essentially a direct current method. A related geophysical method, induced polarization (or spectral induced polarization), measures the transient response and aims to determine
Edmundson Electrical Electrical Distributors, which in 2010 was the fifth largest private company by revenue ($3.4 billion in 2009, $3.9 billion in 2008). Through a number of companies, the Colburn family own a global network of manufacturers, distributors and general purpose retail outlets. Whilst Edmunson Electrical primarily serves the United Kingdom and Ireland, the parent organisation, Marlowe Holdings Investments has an 80.1% stake in the Mainland Europe based preformed plastics distributor, Vink Holdings. Edmundson Electrical Edmundson Electrical Ltd is a privately held electrical distribution company headquartered in Knutsford, Cheshire, incorporated in 1991. It is the largest electrical distributor in the United Kingdom