The basic moving coil meter is suitable only for direct current measurements, usually in the range of 10 μA to 100 mA. Instead of balancing a bridge, values could be directly read off the instrument's scale, which made measurement quick and easy. It gives proportional measurement rather than just detection, and deflection is independent of the orientation of the meter. The coil rotates in a permanent magnetic field and is restrained by fine spiral springs which also serve to carry current into the moving coil. The D'Arsonval–Weston meter movement uses a moving coil which carries a pointer and rotates on pivots or a taut band ligament. These galvanometers were bulky and delicate. While useful in the lab, the devices were very slow and impractical in the field. These were used to measure resistance and voltage by using a Wheatstone bridge, and comparing the unknown quantity to a reference voltage or resistance. The first moving-pointer current-detecting device was the galvanometer in 1820.
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