Ammeter Wattmeter for an alternative use for this instrument. Moving iron ammeters use a piece of iron which moves when acted upon by the electromagnetic force of a fixed coil of wire. The moving-iron meter was invented by Austrian engineer Friedrich Drexler in 1884. This type of meter responds to both direct and alternating currents (as opposed to the moving-coil ammeter, which works on direct current only). The iron element consists of a moving vane attached to a pointer, and a fixed vane, surrounded by a coil. As alternating or direct current flows through the coil and induces a magnetic field
Electrical contractor from the use of electricity. While these are the default minimum requirements and guidelines, some states modify selected areas of the NEC code to suit their specific circumstances. Electrical contractor An electrical contractor is a business person or firm that performs specialized construction work related to the design, installation, and maintenance of electrical systems. An electrical contractor is different from an electrician; an electrician is an individual tradesman and an electrical contractor is a business person or company that employs electricians. Both usually hold licenses and insurances to properly and safely operate a business, protecting the employees and home owners/business