*The hertz is named after the German physicist Heinrich Rudolf Hertz. The name was established by the IEC in 1930. It was adopted by the CGPM (Conférence générale des poids et mesures) in 1960, replacing the previous name for the unit, cycles per second (cps), along with its related multiples, primarily kilocycles (kc) and megacycles (Mc). Hertz largely replaced cycles per second in common use by 1970.