A Galvanometer is different to an Ammeter in the sense that a Galvanometer measures the presence, direction and strength of an electric current in a conductor, where as an Ammeter measures the magnitude of an electric current in a conductor. Galvanometers can be converted into an Ammeter by usually adding a 'shunt' resistor in paralell with the Galvanometer so that the maximum current flows through it as it has a very low resistance, hence the term low resistance Galvanometer.
