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Infobox references. 1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227ea (ISO name), HFC-227 or FM-200, as well as apaflurane (INN), is a colourless, odourless gaseous halocarbon commonly used as a gaseous fire suppression agent.
By definition, an automatic fire suppression system can operate without human intervention. To do so it must possess a means of detection, actuation and delivery. In many systems, detection is accomplished by mechanical or electrical means. Mechanical detection uses fusible-link or thermo-bulb detectors.
Gaseous fire suppression, also called clean agent fire suppression, is the use of inert gases and chemical agents to extinguish a fire. These agents are governed by the National Fire Protection Association (NFPA) Standard for Clean Agent Fire Extinguishing Systems – NFPA 2001 in the US, with different standards and regulations elsewhere.
FM radio channel assignments in the U.S. In the United States, FM broadcasting stations operate on a 20.2 MHz-wide frequency band, spanning from 87.8 MHz to 108 MHz. This is divided into 101 0.2 MHz-wide channels, which are designated as channels 200 through 300. In actual practice, few except the FCC use these channel numbers; the frequencies ...
Graphical depiction of FM broadcasting allotments. The FM broadcast band is a range of radio frequencies used for FM broadcasting by radio stations. The range of frequencies used differs between different parts of the world. In Europe and Africa (defined as International Telecommunication Union (ITU) region 1) and in Australia and New Zealand ...
Shortwave radio received its name because the wavelengths in this band are shorter than 200 m (1,500 kHz) which marked the original upper limit of the medium frequency band first used for radio communications. The broadcast medium wave band now extends above the 200 m / 1,500 kHz limit. Early long-distance radio telegraphy used long waves ...
Position of FM radio in the electromagnetic spectrum. A commercial 35 kW FM radio transmitter built in the late 1980s. It belongs to FM radio station KWNR, in Henderson, Nevada, and broadcasts at 95.5 MHz. FM broadcasting is a method of radio broadcasting that uses frequency modulation (FM) of the radio broadcast carrier wave.
Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing. In analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the ...