Class of accuracy in electrical measurements and voltmeters have a high but not infinite internal impedance. Thus the measured parameters are somewhat altered during the measurements. Let E be the EMF of the source R be the resistance of the load and r be the resistance of the ammeter. The current through the load is I When the ammeter is connected in series with the load the current I is The difference introduced by the measuring device is then, The ratio of the difference to the actual value is Class of accuracy in electrical measurements In electrical engineering class of accuracy is a figure which represents
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