frequency standard
71Rubidium standard — A rubidium standard is a frequency standard in which a specified hyperfine transition of electrons in rubidium 87 atoms is used to control the output frequency. A rubidium standard consists of a gas cell, which has an inherent long term… …
72Caesium standard — A caesium standard or caesium atomic clock is a primary frequency standard in which electronic transitions between the two hyperfine ground states of caesium 133 atoms are used to control the output frequency. They are one of the most accurate… …
73A440 (pitch standard) — For other uses, see A440. A440  Play (help· …
74Orthogonal frequency-division multiplexing — Passband modulation v · d · e Analog modulation AM · …
75Radio-frequency identification — (RFID) is a technology that uses radio waves to transfer data from an electronic tag, called RFID tag or label, attached to an object, through a reader for the purpose of identifying and tracking the object. Some RFID tags can be read from… …
76Utility frequency — The waveform of 230 volt, 50 Hz compared with 110 V, 60 Hz. The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the frequency at which alternating current (ac, also AC) is transmitted from a… …
77Indian Standard Time — (IST) is the time observed throughout India and Sri Lanka, with a time offset of . India does not observe daylight saving time, (DST) or other seasonal adjustments, although DST was used briefly during the Sino–Indian War of 1962 and the… …
78Orthogonal frequency-division multiple access — Multiplex techniques Circuit mode (constant bandwidth) TDM · FDM · SDM Polarization multiplexing Spatial multiplexing (MIMO) …
79Orders of magnitude (frequency) — To help compare different orders of magnitude, the following list describes various frequencies, which is measured in Hertz. Factor (Hz) Multiple Value Item 10−18 1 attohertz (aHz) 2.29 aHz The Hubble Constant (once in 13.8 billion years) 10−15 1 …
80Cumulative frequency analysis — is the applcation of estimation theory to exceedance probability (or equivalently to its complement). The complement, the non exceedance probability concerns the frequency of occurrence of values of a phenomenon staying below a reference value.… …
