The volt and ampere sensitivity of a moving coil galvanometer is treated in terms of the electrical circuit, the galvanometer design, and the time used for taking observation. Only cases where the current is constant are discussed; ballistic use is not treated. The term ``resolution of galvanometer readings'' is suggested to describe the experimentally determined change in potential difference or current that can be measured with a stated probable error in a stated measuring time under actual working conditions. The use of a galvanometer as a deflecting, partial‐deflecting and null instrument is discussed.