Weston, Edward

SUBJECT AREA: Electricity

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b. 9 May 1850 Oswestry, England

d. 20 August 1936 Montclair, New Jersey, USA

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English (naturalized American) inventor noted for his contribution to the technology of electrical measurements.

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Although he developed dynamos for electroplating and lighting, Weston's major contribution to technology was his invention of a moving-coil voltmeter and the standard cell which bears his name. After some years as a medical student, during which he gained a knowledge of chemistry, he abandoned his studies. Emigrating to New York in 1870, he was employed by a manufacturer of photographic chemicals. There followed a period with an electroplating company during which he built his first dynamo. In 1877 some business associates financed a company to build these machines and, later, arc-lighting equipment. By 1882 the Weston Company had been absorbed into the United States Electric Lighting Company, which had a counterpart in Britain, the Maxim Weston Company. By the time Weston resigned from the company, in 1886, he had been granted 186 patents. He then began the work in which he made his greatest contribution, the science of electrical measurement.

The Weston meter, the first successful portable measuring instrument with a pivoted coil, was made in 1886. By careful arrangement of the magnet, coil and control springs, he achieved a design with a well-damped movement, which retained its calibration. These instruments were produced commercially on a large scale and the moving-coil principle was soon adopted by many manufacturers. In 1892 he invented manganin, an alloy with a small negative temperature coefficient, for use as resistances in his voltmeters.

The Weston standard cell was invented in 1892. Using his chemical knowledge he produced a cell, based on mercury and cadmium, which replaced the Clark cell as a voltage reference source. The Weston cell became the recognized standard at the International Conference on Electrical Units and Standards held in London in 1908.

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Principal Honours and Distinctions

President, AIEE 1888–9. Franklin Institute Elliott Cresson Medal 1910, Franklin medal 1924.

Bibliography

29 April 1890, British patent no. 6,569 (the Weston moving-coil instrument). 6 February 1892, British patent no. 22,482 (the Weston standard cell).

Further Reading

D.O.Woodbury, 1949, A Measure of Greatness. A Short Biography of Edward Weston, New York (a detailed account).

C.N.Brown, 1988, in Proceedings of the Meeting on the History of Electrical Engineering, IEE, 17–21 (describes Weston's meter).

H.C.Passer, 1953, The Electrical Manufacturers: 1875–1900, Cambridge, Mass.

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