Basic DC ammeter and Multirange Ammeter

DC Ammeter – The PMMC galvanometer constitutes the basic movement of a dc ammeter. Since the coil winding of a basic movement is small and light, it can carry only very small currents. When large currents are to be measured, it is necessary to bypass a major part of the current through a resistance called a shunt.The resistance of shunt can be calculated using conventional circuit analysis.

MultirangeAmmeters:
The current range of the dc ammeter may be further extended by a number of shunts, selected by a range switch. Such a meter is called a multirange ammeter.