Aperiodic frequency is the rate of incidence or occurrence of non-cyclic phenomena, including random processes such as radioactive decay. It is expressed in units of measurement of reciprocal seconds or, in the case of radioactivity, becquerels. It is defined as a ratio, f = N/T, involving the number of times an event happened (N) during a given time duration (T); it is a physical quantity of type temporal rate.

See also