Ammeter through a wire which expands as it heats. Although these instruments have slow response time and low accuracy, they were sometimes used in measuring radio-frequency current. These also measure true RMS for an applied AC. In much the same way as the analogue ammeter formed the basis for a wide variety of derived meters, including voltmeters, the basic mechanism for a digital meter is a digital voltmeter mechanism, and other types of meter are built around this. Digital ammeter designs use a shunt resistor to produce a calibrated voltage proportional to the current flowing. This voltage is then measured by
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