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
Electrical Artificer Electrical Artificer An Electrical Artificer (EA) is an electrical technician competent in the electrical maintenance of ship's machinery such as engines and generators. This was originally a Royal Navy term for those trained and competent in the installation and maintenance of ships electrical systems. The title has been replaced in the Royal Navy . However the Irish Naval Service continues to use the term 'Electrical Artificer' (EA) for electrical technicians. A distinctive propeller insignia is worn to identify these personnel. Training is completed in the National Maritime College which is incorporated into the Cork Institute of Technology. Prior to its