Edward Weston (chemist) instruments for electric current—the modern foundation for the voltmeter, ammeter and wattmeter. In 1888 he formed the Weston Electrical Instrument Corporation which would become famous for its voltmeters, ammeters, wattmeters, ohmmeters, frequency meters, transformers, and transducers. Weston developed a method for producing a "true" permanent magnet. Weston conceived of and built a magnetic speedometer. Weston also developed the dashboard ammeter for Harley-Davidson motorcycles. Also in 1888, Weston became president of the American Institute of Electrical Engineers (AIEE) until 1889. Weston invented and patented the saturated cadmium cell in 1893. The cathode in the cell is an amalgam of cadmium with
Electrical mobility from exhaust gases on an industrial scale. The particles are given a charge by exposing them to ions from an electrical discharge in the presence of a strong field. The particles acquire an electrical mobility and are driven by the field to a collecting electrode. Instruments exist which select particles with a narrow range of electrical mobility, or particles with electrical mobility larger than a predefined value. The former are generally referred to as "differential mobility analyzers". The selected mobility is often identified with the diameter of a singly charged spherical particle, thus the "electrical-mobility diameter" becomes a characteristic of