illuminance flares being used during military trail exercises A flare, besides sometimes called a fusée or bengala in some latin-speaking countries, is a type of pyrotechnic that produces a bright ignite or intense heat without an plosion. Flares are used for distress sign, miniature, or defensive countermeasures in civilian and military applications. Flares may be ground pyrotechnics, projectile pyrotechnics, or parachute-suspended to provide maximal illumination fourth dimension over a large area. Projectile pyrotechnics may be dropped from aircraft, fired from rocket or artillery, or deployed by flare guns or handheld percussive tubes.
Reading: Flare – Wikipedia
history [edit ]
The earliest recorded use of gunpowder for signaling purposes was the ‘signal bomb ‘ used by the Chinese Song Dynasty as the Mongol-led Yuan Dynasty besieged Yangzhou in 1276. [ 1 ] These soft-shelled bombs, timed to explode in mid-air, were used to send messages to a withdrawal of troops far in the distance. Another mention of the signal turkey appears in a textbook dating from 1293 requesting their solicitation from those still stored in Zhejiang. [ 1 ] A sign gunman appears in Korea by 1600. The Wu I Thu Phu Thung Chih or Illustrated Military Encyclopedia written in 1791 depicts a sign gun in an example. [ 2 ]
chemistry [edit ]
Three road flares burning
A ceremonious flare pistol. This particular model uses 26.5mm flares ( manufactured by Patel Ballistics ). Flares produce their light through the combustion of a firework composing. The ingredients are varied, but often based on strontium nitrate, potassium nitrate, or potassium perchlorate and blend with a fuel such as charcoal, sulphur, sawdust, aluminum, magnesium, or a desirable polymeric resin. [ 3 ] Flares may be colored by the inclusion of pyrotechnic colorants. calcium flares are used submerged to illuminate subaqueous objects .
Movement against perchlorate flares [edit ]
many in-service discolor sign flares and spectrally balanced decoy flares contain perchlorate oxidizers. Perchlorate, a type of salt in its solid shape, dissolves and moves quickly in groundwater and open water. even in low concentrations in drink urine supplies, perchlorate is known to inhibit the consumption of iodine by the thyroid gland. While there are presently no US federal drink urine standards for perchlorate, some states have established public health goals or action levels, and some are in the process of establishing state of matter maximum contaminant levels. For exercise, the US Environmental Protection Agency have studied the impacts of perchlorate on the environment american samoa well as drink urine. [ 4 ] California has besides issued guidance regarding perchlorate use. [ 5 ] US courts have taken action regarding the use of perchlorate in manufacturing firework devices such as flares. For example, in 2003, a federal zone court in California found that Comprehensive Environmental Response, Compensation and Liability Act ( CERCLA ) applied because perchlorate is burnable and consequently a “ characteristic ” hazardous barren. ( see Castaic Lake Water Agency v. Whittaker, 272 F. Supp. 2d 1053, 1059–61 ( C.D. Cal. 2003 ) ) .
civilian habit [edit ]
red Flares used at a demonstration in Vienna In the civilian world, flares are normally used as signals, and may be ignited on the ground or fired as an aerial bespeak from a pistol -like flare gun, or launched from a collected tube. Flares are normally found in marine survival kits .
Maritime distress signal [edit ]
loss flares, either sent as a rocket or held in the hand, are widely recognized as a nautical distress signal. [ 6 ] The International Convention for the Safety of Life at Sea ( SOLAS ) has standards for ocular signals, including both hand-held and antenna flares. Handheld flares must burn for at least 1 infinitesimal at an average luminosity of 15,000 candelas, while aeriform flares must burn for at least 40 seconds with 30,000-candela average luminosity. [ 7 ] Both should burn in a bright red tinge. Nations that are members of SOLAS ask vessels to carry ocular signals on board .
fusee [edit ]
Another type of flare is the fusee, which burns for 5–60 minutes with a bright bolshevik light. Fusees are normally used to indicate obstacles or advise caution on roadways at night ; in this use they are besides called highway flares, road flares, or ground flares. They are normally found in wayside emergency kits.
Fusees are besides known as railroad flares and are normally used to perform hand signals in vilify transportation applications. Since they can be used merely once, fusees nowadays are normally intended for emergency use ( as opposed to the lanterns typically used during convention operating conditions ). however, in the days before train radio communications, fusees were used to keep trains apart in dark district. A dragoon fuse was timed to burn for ten minutes and quantities were dropped behind a aim to ensure a safe spacing. If a succeed train encountered a burning fusee it was not to pass until the fusee burned out. Fusees made specifically for dragoon use can be distinguished from highway fusees by a sharp steel transfix at one conclusion, used to embed the fuse upright in a wooden railroad bind. In forestry and firefighting, fusees are sometimes used in wildland displace suppression and in the ignition of manipulate burns. They ignite at 191 °C ( 376 °F ) and burn a hot as 1,600 °C ( 2,900 °F ). [ 8 ] They are specially effective in igniting burnouts or backburns in very dry conditions, but not therefore effective when fuel conditions are damp. Since controlled burns are often done during relatively high humidity levels ( on the grounds that they could not be safely contained during periods of identical low humidity ), the driptorch is more effective and more frequently used. Fusees are besides normally carried by wildland firefighters for emergency use, to ignite an escape fire in surrounding fuels in encase of being overrun by a fire if no other escape routes are available. Calcium phosphide is much used in naval flares, as in liaison with urine it liberates phosphine which self ignites in liaison with air ; it is much used together with calcium carbide which releases acetylene. Law enforcement besides may use flares ( either propped on a bipedal or laid flat ) to signal traffic hazards or that a road is blocked, much as a more visible replacement for traffic cones. [ 9 ] [ 10 ] [ 11 ] Law enforcement in the United States normally use magnesium [ 12 ] based flares that last from 15-30 minutes. [ 13 ]
military use [edit ]
Maritime signal flare [edit ]
In 1859, Martha Coston patented the Coston flare based on early work by her die husband Benjamin Franklin Coston. [ 14 ] It was used extensively by the U.S. Navy during the Civil War and by the United States Life-Saving Service to signal to other ships and to shore .
miniature [edit ]
In 1922, a “ land flare ” was an antenna candle attached to a chute and used for landing an airplane in the dark. The flare burned for less than 4 minutes and the candle power was about 40,000 lumens. [ 15 ]
countermeasure [edit ]
A especial assortment of flares is used in military aircraft as a defensive countermeasure against heat-seeking missiles. These flares are normally discharged individually or in salvo by the pilot or mechanically by tail-warning devices, and are accompanied by vigorous evasive steer. Since they are intended to deceive infrared missiles, these flares burn at temperatures of thousands of degrees, incandescing in the visible spectrum a well .
Tripflares [edit ]
Flares connected to tripwires are used to guard an area against percolation. The flare begins burning when the tripwire is triggered, providing both dismay and illuminance .
regulation [edit ]
Under the UN hazard count system, pyrotechnic flares are designated class 1.4 explosives. [ 16 ] several U.S. states, including California and Massachusetts, have begun regulating levels of potassium perchlorate, which can be dangerous at certain levels in drink water. Contaminated drink water can lead to such symptoms as gastric excitation, nausea, vomiting, fever, bark rashes, and even fateful aplastic anemia. [ 17 ]
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See besides [edit ]
References [edit ]
far read [edit ]
- Wallbank, Alister (2001). “Can anybody see me? (modified reprint from DIVER 2000; 45 (2) February: 72–74)”. Journal of the South Pacific Underwater Medicine Society. 31 (2): 116–119 .
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