Carbon monoxide detector
In the late 1990s, Underwriters Laboratories changed the definition of a single station CO detector with a sound device to carbon monoxide (CO) alarm.
In a study by Underwriters Laboratories, "Sixty percent of Americans could not identify any potential signs of a CO leak in the home".
[9] The primary purpose of CO detectors is to sound an alarm to warn occupants of an enclosed space of a dangerous level of carbon monoxide.
[10] In some instances, it's worth noting that a red flashing without accompanying sounds could indicate a different condition or simply inform the user about a malfunction.
[11] Wireless home safety devices are available that link carbon monoxide detectors to vibrating pillow pads, strobes, or a remote warning handset.
Alerting methods include: Early designs used a chemical detector consisting of a white pad that faded to a brownish or blackish color in the presence of carbon monoxide.
A biomimetic sensor works in a fashion similar to hemoglobin which darkens in the presence of CO proportional to the amount of carbon monoxide in the surrounding environment.
[13] The electrochemical detector uses the principle of a fuel cell to generate an electrical current when the gas to be detected undergoes a chemical reaction.
The generated current is precisely related to the amount of carbon monoxide in the immediate environment close to the sensor.
Essentially, the electrochemical cell consists of a container, two electrodes, connection wires, and an electrolyte, typically sulfuric acid.
Thin wires of the semiconductor tin dioxide on an insulating ceramic base provide a sensor monitored by an integrated circuit.
Although all home detectors use an audible alarm signal as the primary indicator, some versions also offer a digital readout of the CO concentration, in parts per million (PPM).
Portable meters which display CO concentration down to a few PPM are more sensitive than home safety CO detectors and correspondingly much more expensive.
In Canada, CO alarm requirements came into effect on October 15, 2014 in Ontario,[15] there is a strong movement in Alberta to make CO detectors mandatory in all homes.
[17] House builders in Colorado are required to install carbon monoxide detectors in new homes by a bill signed into law in March 2009.
Lofgren, along with his wife and children were found dead in their home near Aspen, Colorado on Nov. 27, 2008, victims of carbon-monoxide poisoning.
In New York State "Amanda's Law" (A6093A/C.367) requires one- and two-family residences that have fuel-burning appliances to have at least one carbon monoxide alarm installed on the lowest story having a sleeping area, effective February 22, 2010.
In addition, New York State contractors must install a carbon monoxide detector when replacing a fuel-burning water heater or furnace if the home is without an alarm.
The law is named for Amanda Hansen, a teenager who died from carbon monoxide poisoning from a defective boiler while at a sleepover at a friend's house.
requires a carbon monoxide detector to be installed in dwelling units that contain or are serviced by a carbon-based fuel appliance or other device that produces by-products of combustion.
The reasoning behind these changes is to reduce calls to fire stations, utilities and emergency response teams when the levels of CO are not life threatening.
