Ammeter permanent magnet causes the coil to move. The modern form of this instrument was developed by Edward Weston, and uses two spiral springs to provide the restoring force. The uniform air gap between the iron core and the permanent magnet poles make the deflection of the meter linearly proportional to current. These meters have linear scales. Basic meter movements can have full-scale deflection for currents from about 25 microamperes to 10 milliamperes. Because the magnetic field is polarised, the meter needle acts in opposite directions for each direction of current. A DC ammeter is thus sensitive to which way round
Jim Measures Hull Kingston Rovers in the 1964 Challenge Cup Final during the 1963–64 season at Wembley Stadium, London on Saturday 9 May 1964, in front of a crowd of 84,488. Jim Measures is the father of rugby league of the 1990s for St. Helens Colts, and A-Team, Leigh and Widnes Vikings; Neil Measures. Jim Measures James Measures (born 14 April 1939), also known by the nickname of "Jim", is an English former professional rugby league footballer who played in the 1950s and 1960s. He played at representative level for Great Britain, and at club level for St Helens, Widnes and the