Ammeter portable hand-held clamp-on ammeter is a common tool for maintenance of industrial and commercial electrical equipment, which is temporarily clipped over a wire to measure current. Some recent types have a parallel pair of magnetically soft probes that are placed on either side of the conductor. Ammeter An ammeter (from Ampere Meter) is a measuring instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as "milliammeters" or "microammeters". Early ammeters were laboratory instruments which relied on
William Edward Ayrton electrical engineering, or of applied physics, at the Central Technical College, South Kensington. He published, both alone and jointly with others, a large number of papers on physical, and in particular electrical, subjects, and his name was especially associated, together with that of Professor John Perry, with the invention of a long series of electrical measuring instruments, including the spiral-spring ammeter, and the wattmeter. They also worked on railway electrification, produced a dynamometer and the first electric tricycle. Ayrton is also known for his work on the electric searchlight. Ayrton died in London in 1908 and is buried in Brompton