A carbon monoxide detector or CO detector is a device that detects the presence of carbon monoxide (CO) gas to prevent carbon monoxide poisoning. In the late 1990s, Underwriters Laboratories changed their definition of a single station CO detector with a sound device in it into a carbon monoxide (CO) alarm. This applies to all CO safety alarms that meet UL 2034 standards; But for passive indicators and system devices that meet UL 2075, UL refers this as a carbon monoxide detector.
CO is a colorless, tasteless and odorless compound produced by imperfect combustion of a carbonaceous material. It is often referred to as a "silent killer" because it is virtually undetectable by humans without the use of detection technology and, in a study by Underwriters Laboratories, "Sixty percent of Americans can not identify potential signs of CO leak at home". Increased CO levels can be harmful to humans depending on the amount and duration of exposure. Smaller concentrations can be harmful for longer periods of time while higher concentrations will reduce exposure time to be hazardous.
CO detectors are designed to measure CO levels over time and sound an alarm before harmful CO levels accumulate in an environment, giving people adequate warning for safe ventilation in the area or displacement. Some detectors connected to the system also remind monitoring services that can deliver emergency services if needed.
While CO detectors do not function as smoke detectors and vice versa, double smoke/CO detectors are also sold. Smoke detectors detect smoke generated by fires that burn or burn, while CO detectors detect and warn people about the harmful CO buildup caused, for example, by malfunctioning fuel burning devices. At home, some common CO sources include open flame, space heater, water heater, blocked chimney or car running inside the garage.
Video Carbon monoxide detector
Installation
The device, which sells for $ 120- $ 150 USD and is widely available, can be battery-operated or air-conditioned (with or without battery backup). Battery life has increased as technology has evolved and certain battery-powered devices now advertise a battery life of up to 10 years. All CO detectors have "test" buttons like smoke detectors.
CO detectors can be placed near the ceiling or near the floor because the CO is very close to the same density as the air.
Because CO is colorless, tasteless and odorless (unlike smoke from fire), detection in a home environment is not possible without such a warning device. It is a highly toxic inhalation and attaches to hemoglobin (in the bloodstream) with a 200x affinity stronger than oxygen, generating inadequate amounts of oxygen through the body.
When carbon monoxide detectors are introduced into the market, they have a limited lifespan of 2 years. But technological developments have improved this and now many advertise for up to 10 years. The newer models are designed to indicate the need to be replaced after the time range even though there are many examples of detectors operating far beyond this point.
According to the 2005 edition of carbon monoxide guidelines, NFPA 720, published by the National Fire Protection Association, sections 5.1.1.1 and 5.1.1.2, all CO "detectors must be located outside of each separate sleeping area around the bedroom," and each detector " should be placed on the wall, ceiling or other location as specified in the installation instructions that accompany the unit. "
According to the 2009 edition of IRC, published by the Council of International Code, section R315.1, "For new construction, approved carbon monoxide alarms should be installed outside each separate sleeping area around the bedroom in the residential unit where fueled equipment installed and in residential units which have an attached garage ", and section 315.2," Where permitting work takes place in an already existing garage or residential dwelling where the existing fuel-burning equipment exists, the carbon monoxide alarm must be provided in accordance with Section R315.1. "
The installation location varies by manufacturer. Producers' recommendations are different for a given level based on research conducted with their own specialized detectors. Therefore, be sure to read the installation manual provided for each detector before installing.
CO detectors are available as stand-alone models or devices that are connected to the system and monitored. System-connected detectors, which can be transferred to either a security or fire panel, are monitored by a central station. If the residence is empty, the occupant is asleep or the occupants have suffered the effects of CO, the central station can be alerted with high CO gas concentrations and can send the proper authority to investigate.
The gas sensor in the CO alarm has a limited life span and can not be determined, usually two to five years. The test button on the CO alarm only tests the battery and the circuit, not the sensor. The CO alarm should be tested with a calibrated test gas external source, as recommended by the latest version of NFPA 720. Alerts over five years old must be replaced but should be checked at installation and at least annually during the manufacturer's warranty period.
Maps Carbon monoxide detector
Sensor
The initial design is basically a white pad that will fade into a brownish or blackish color if carbon monoxide is present. Such chemical detectors are cheap and widely available, but only give visual warning of a problem. Because carbon monoxide-related deaths increased during the 1990s, audible alarms became standard.
The alarm points on the carbon monoxide detector are not a simple alarm level (as in smoke detectors) but are a function of time concentration. At lower concentrations (eg 100 parts per million) the detector will not sound the alarm for tens of minutes. At 400 parts per million (PPM), the alarm will sound within minutes. This time-concentration function is intended to mimic the absorption of carbon monoxide in the body while also preventing false alarms due to relatively common sources of carbon monoxide such as cigarette smoke.
There are four types of sensors available and they vary in terms of cost, accuracy, and response speed, which are listed below. The last three types include sensor elements that typically last up to 10 years. At least one available CO detector which includes battery and sensor in replaceable module. Most CO detectors have no replaceable sensors.
Opto-chemical
The detector consists of a colored chemicals pad that changes color in reaction with carbon monoxide. They only provide qualitative warnings about gas. The main advantage of these detectors is that they are the lowest cost, but the downside is that they also offer the lowest protection level.
Salah satu reaksi yang digunakan untuk deteksi karbon monoksida adalah oksidasi katalitik kalium disulfitopalladate (II):
As the reaction progresses, the release of palladium atoms causes the color to change from yellow to brown to black.
Biomimetic
Biomimetic sensors work in a manner similar to hemoglobin that darkens the presence of CO in proportion to the amount of carbon monoxide in the environment. It uses cyclodextrin, chromophores, and a number of metal salts. These can be viewed directly or connected to infrared sources of photons such as LED IR and then monitored using photodiode. Battery life usually lasts 2-3 years with conventional alkaline, but lithium battery will survive the product. Biotechnology-based sensors have a useful operational life of 6 years. These products are the first to enter the mass market, but because they are more expensive than other sensors, they are mostly used in upscale and RV areas. This technology has been improved and is the most reliable technology, according to a report from Lawrence Berkeley National Laboratory. This technology is the only false alarm that is tested for free and is preferred by those with larger facilities such as hospitals, hotels and apartments that use air fresheners, alcohol and other disinfectants where the cost of one false alarm is very high. This technology is found in the United States and is manufactured in California.
Electrochemical
This is a type of fuel cell that is not designed to generate power, designed to produce a signal current that is precisely related to the amount of target gas (in this case carbon monoxide) in the atmosphere. Current measurements give a measure of the concentration of carbon monoxide in the atmosphere. Basically the electrochemical cell consists of a container, two electrodes, a connection cable and an electrolyte - usually sulfuric acid. Carbon monoxide is oxidized in one electrode to carbon dioxide when oxygen is consumed in another electrode. For the detection of carbon monoxide, electrochemical cells have advantages over other technologies because they have very accurate and linear outputs against carbon monoxide concentrations, require minimal power when operated at room temperature, and have a prolonged lifetime (usually commercially available cells now have a lifetime five years or more). Until recently, the cost of these cells and concerns about their long-term reliability has limited the use of this technology in the market, although these concerns are now heavily addressed. This technology is now the dominant technology in the US and Europe.
Semiconductor
Thin wires from tin semiconductor dioxide at isolation ceramic bases provide sensors monitored by integrated circuits. This sensing element needs to be heated to about 400 ° C to operate. Oxygen increases the resistance of tin dioxide while carbon monoxide reduces resistance. The integrated circuit monitors the resistance of the sensing element. The lifespan is about five to 10 years.
The large power demand of this sensor means that it is usually turned on from the mains. A battery powered pulsating sensor is available with a lifetime in a few months.
This technology has traditionally found high utility in Japan and the far east with some market penetration in the United States. But the superior performance of electrochemical cell technology began to replace this technology.
Digital
Although all home detectors use alarm signals that can be heard as a leading indicator, some versions also offer digital readings of CO concentrations, in parts per million. Typically, they can display current readings and peak readings of the highest level memory measured over a period of time. This sophisticated model costs a little more but if not the same as the basic model.
Digital models offer the advantage of being able to observe levels below the alarm threshold, learning about levels that may occur during absence, and assessing the level of danger if the alarm sounds. They can also assist emergency responders in evaluating levels of exposure or hazards in the past or ongoing.
Portable
Portable CO detectors are also available; this is typically used for professional applications or in some cases by consumers such as property managers for maintenance and diagnostic issues (ie sources of CO leakage). Most offer real-time CO measurements up to several ppm (typically displayed on digital screens), and are more expensive than home security CO detectors (eg ~ $ 250 vs $ 25). There are two types of portable detectors, designed for airplanes, cars, and trucks. They will warn drivers and passengers if there is a CO danger. Another type is used by industrial hygiene experts and first responders. Digital responsive and fast responsive portable CO type detectors are usually a better choice for real on the go applications because they respond to low CO levels in seconds rather than minutes or hours (which is the case for a housing alarm registered in UL2034 ).
Wireless
A wireless home security solution is available that connects the carbon monoxide detector to the vibrating cushion pad, the light, or the remote warning handset. This allows those who have obstacles such as loud, partially visible, people who sleep soundly or weak people in precious minutes to get up and get out when carbon monoxide occurs in their property.
Regulations in the United States
In the US (as per January 2017) 32 states have enacted laws on carbon monoxide detectors, and another 11 have announced regulations on CO detectors, as well as in Washington, D.C. and New York City. In Canada, the CO alarm requirement takes effect on October 15, 2014 in Ontario, there is a strong movement in Alberta to make CO detectors compulsory in all homes.
Installing a CO detector is essential to ensure protection from inhaling toxic gases. More and more states are making laws for their installation as mandatory features.
Home builders in Colorado are required to install a carbon monoxide detector in a new home in a bill signed into law in March 2009 by the state legislature. House Bill 1091 requires installation of detectors in new homes and resold near bedrooms and rented apartments and homes. It came into effect on July 1, 2009. The law was introduced after the death of investment banker Denver, Parker Lofgren and his family. Lofgren, along with his wife and children, were found dead in their home near Aspen, Colorado on November 27, 2008, victims of carbon monoxide poisoning.
In the State of New York, the "Law of Amanda" (A6093A/C.367) requires the residence of one and two families with fuel-burning equipment having at least one carbon monoxide alarm mounted on the lowest story with sleeping area, effective February 22, 2010. Although houses built before January 1, 2008 are allowed to have battery-powered alarms, houses built after that date must have a cable alarm. In addition, the New York State contractor must install a carbon monoxide detector when replacing a water heater or a fuel-burning furnace if the house is without alarm. The law was named after Amanda Hansen, a teenager who died of carbon monoxide poisoning from a broken boiler while staying at a friend's house.
Alaska House Bill 351 requires a carbon monoxide detector installed in a residential unit containing or serviced by a carbon-based device or other device producing a combustion product.
In July 2011, California required the installation of a carbon monoxide detector in an existing single family home, with multifamily homes after 2013. CA Law 2015 requires all new installations of smoke and CO alarms to be serviceable 10 years. The existing alarm may not need to be replaced for homeowners, see local code. The required alarm locations also vary according to local enforcement agencies.
In Maine all rental units must have a recommended carbon monoxide and non rental home detector but are not required to have a carbon monoxide detector
Standard
- North America
The Canadian Mortgage and Housing Association reports, "The Canadian standards organizations (CSAs) and the United States (Underwriters Laboratories or UL) have coordinated the writing of CO standards and product testing standards in 2010 prohibiting showing CO levels of less than 30 ppm in digital display. also requires an alarm to sound at a higher CO level than with the previous standard edition.The reason behind this change is to reduce calls to fire stations, utilities and emergency response teams when CO level is not life-threatening This change will also reduce the number of calls to these agents are due to the inappropriateness of the detector or the presence of other gases.As a result, the new alarm will not sound at CO concentrations up to 70 ppm Note that this concentration significantly exceeds Canadian health guidelines, "(and also more than US Occupational Safety and Health Authority OSHA) Permitted exposure permit ts, yan g in 50 ppm.)
- UK
In the UK, a domestic alarm/Type-B compatible with BS EN 50291: 2001 should issue audible alarms after about 3 minutes of exposure with 300 ppm CO, or 10 to 40 minutes at 100 ppm, or 60 to 90 minutes at 50 ppm.
References
External links
- Mike Busch (2003-11-09). "Carbon Monoxide Detector". Avweb.com. Archived from original in 2004-02-21 . Retrieved 2017-10-18 .
- "Carbon Monoxide Alarm Considerations for Code Authorities" (PDF) . UL. 2014 [First published 2009]. Archived from the original (PDF) in 2017-10-18 . Retrieved 2017-10-18 .
Source of the article : Wikipedia
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