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A carbon monoxide detector or CO detector is a device that detects the presence of the carbon monoxide (CO) gas in order to prevent carbon monoxide poisoning. In the late 1990s Underwriters Laboratories (UL) changed their definition of a single station CO detector with a sound device in it to a carbon monoxide (CO) alarm. This applies to all CO safety alarms that meet UL 2034; however for passive indicators and system devices that meet UL 2075, UL refers to these as carbon monoxide detectors. CO is a colorless, tasteless and odorless compound produced by incomplete combustion of carbon containing materials. It is often referred to as the "silent killer" because it is virtually undetectable without using detection technology and most do not realise they are being poisoned. Elevated levels of CO can be dangerous to humans depending on the amount present and length of exposure. Smaller concentrations can be harmful over longer periods of time while increasing concentrations require diminishing exposure times to be harmful.〔NFPA 720: Standard for the Installation of Household Carbon Monoxide (CO) Warning Equipment, 2005 Edition, Annex B Dangers of Carbon Monoxide, B.1 Carbon Monoxide, Table B.1 Symptoms of Carbon Monoxide Exposure Based on Concentration〕 CO detectors are designed to measure CO levels over time and sound an alarm before dangerous levels of CO accumulate in an environment, giving people adequate warning to safely ventilate the area or evacuate. Some system-connected detectors also alert a monitoring service that can dispatch emergency services if necessary. While CO detectors do not serve as smoke detectors and vice versa, dual smoke/CO detectors are also sold. Smoke detectors detect the smoke generated by flaming or smoldering fires, whereas CO detectors detect and warn people about dangerous CO buildup caused, for example, by a malfunctioning fuel-burning device. In the home, some common sources of CO include open flames, space heaters, water heaters, blocked chimneys or running a car inside a garage. ==Installation== The devices, which retail for $15–$60 USD and are widely available, can either be battery-operated or AC powered (with or without a battery backup). Battery lifetimes have been increasing as the technology has developed and certain battery powered devices now advertise a battery lifetime of over 6 years. Some smoke detectors are equipped with an internal rechargeable battery backup that recharges when the detector is receiving AC power. All CO detectors have "test" buttons like smoke detectors. CO detectors can be placed near the ceiling or near the floor because CO is very close to the same density as air. Since CO is colorless, tasteless and odorless (unlike smoke from a fire), detection in a home environment is impossible without such a warning device. It is a highly toxic inhalant and attaches to the hemoglobin (in the blood stream) with an affinity 200x stronger than oxygen,〔Guyton A C: Medical Physiology 12ed. 2010, page 502〕 producing inadequate amounts of oxygen traveling through the body. In North America, detectors are required in new construction in the U.S. states of Alaska, California, Colorado, Connecticut, Florida, Georgia, Illinois, Maryland, Massachusetts, Minnesota, New Jersey, New York, Oregon, Rhode Island, Texas, Vermont, Virginia, Washington (also in existing homes with some exemptions),〔(【引用サイトリンク】title=WAC 51-51-0315: Section R315—Carbon monoxide alarms. )〕〔(【引用サイトリンク】title=RCW 19.27.530: Carbon monoxide alarms — Requirements — Exemptions — Adoption of rules. )〕 Wisconsin and West Virginia, as well as New York City and the Canadian provinces of Ontario and Alberta (homes with a secondary suite or new homes with a fuel-burning appliance). When carbon monoxide detectors were introduced into the market, they had a limited lifespan of 2 years. However technology developments have increased this and many now advertise up to 7 years. Newer models are designed to signal a need to be replaced after that time-span although there are many instances of detectors operating far beyond this point. According to the 2005 edition of the carbon monoxide guidelines, NFPA 720,〔NFPA 720: Standard for the Installation of Household Carbon Monoxide (CO) Warning Equipment, 2005 Edition〕 published by the National Fire Protection Association, sections 5.1.1.1 and 5.1.1.2, all CO detectors “shall be centrally located outside of each separate sleeping area in the immediate vicinity of the bedrooms,” and each detector “shall be located on the wall, ceiling or other location as specified in the installation instructions that accompany the unit.” According to the 2009 edition of the IRC,〔2009 International Residential Code® for One- and Two-family Dwellings〕 published by the International Code Council, section R315.1, "For new construction, an approved carbon monoxide alarm shall be installed outside of each separate sleeping area in the immediate vicinity of the bedrooms in dwelling units within which fuel-fired appliances are installed and in dwelling units that have attached garages", and section 315.2, "Where work requiring a permit occurs in existing dwellings that have attached garages or in existing dwellings within which fuel-fired appliances exist, carbon monoxide alarms shall be provided in accordance with Section R315.1." Installation locations vary by manufacturer. Manufacturers’ recommendations differ to a certain degree based on research conducted with each one’s specific detector. Therefore, make sure to read the provided installation manual for each detector before installing. CO detectors are available as stand-alone models or system-connected, monitored devices.〔"Top 5 Things to Know About CO," LifeSafety magazine, Fall 2006〕 System-connected detectors, which can be wired to either a security or fire panel, are monitored by a central station. In case the residence is empty, the residents are sleeping or occupants are already suffering from the effects of CO, the central station can be alerted to the high concentrations of CO gas and can send the proper authorities to investigate. The gas sensors in CO alarms have a limited and indeterminable life span, typically two to five years. The test button on a CO alarm only tests the battery and circuitry, not the sensor. CO alarms should be tested with an external source of calibrated test gas, as recommended by the latest version of NFPA 720. Alarms over five years old should be replaced but they should be checked on installation and at least annually during the manufacturers warranty period. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「carbon monoxide detector」の詳細全文を読む スポンサード リンク
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