Cycle per second operation. Thus, one becquerel is one event per second "on average", whereas one hertz is one event per second on a regular cycle. Cycle can also be a unit for measuring usage of reciprocating machines, especially presses, in which cases "cycle" refers to one complete revolution of the mechanism being measured (i.e. the shaft of a reciprocating engine). Cycle per second The cycle per second was a once-common English name for the unit of frequency now known as the hertz (Hz). The plural form was typically used, often written cycles per second, cycles/second, c.p.s., c/s, ~, or, ambiguously, just cycles.
Gray (unit) Gray (unit) The gray (symbol: Gy) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose which measures the energy deposited in a unit mass at a certain position, and of the radiation quantity kerma, which is the amount of energy that is transferred from photons to electrons per unit mass at a certain position. The corresponding cgs unit to the gray is the rad (equivalent to