More and more citizens are realizing the importance of installing quality CO detectors in their residences. While most fire departments will not endorse or recommend a CO detector, it's helpful to have a reliable source of information available when citizens seek our advice. An October 2001 Consumer Reports (CR) magazine contains information that citizens may find useful and can assist fire department officials as they answer citizen inquiries.
Consumer Reports tested nineteen (19) widely available carbon monoxide detectors. The CR ratings (www.consumerreports.org ) listed the tested detectors in order of overall score, based mainly on the speed of the alarm's response to CO and how quickly the alarm stopped once the gas was cleared out of the affected area. The scoring scale for the tested devices was 0 to 100: 81 to 100 excellent; 61 to 80 very good; 41 to 60 good; 21 to 40 fair; and below 40 poor.
CR tested both battery-operated and AC powered units. The AC powered units included units which were plug-in models but which had a version that can be hard-wired into a home's electrical circuit. They also included units with power cords that can be hung or placed on a table. Some include battery backup so they can function during a blackout.
Using the time specified in the Underwriters Laboratory (UL) standard, CR judged the response of the alarm's speed of detection when placed in CO contaminated atmosphere. Detectors rated Excellent or Very Good always went off within the time specified. Those rated Good closely missed the target time once or twice. Detectors rated Fair experienced more frequent late alarms than permitted by the UL standard.
CR's examination of the CO detectors also included a test for "recovery" or how fast the alarm silenced itself when the detector was exposed to fresh air after an exposure test. Detectors receiving the highest scores shut off in 3 to 6 minutes. Models judged to be Fair took about an hour. The worst units took several hours to recover and were rated poor.
- CR also tested the CO detectors for their ability to sound again, "repeat," if the Hush or Reset button was pressed. For the test purposes the time was expressed in minutes and applied when CO levels persisted in the affected area. Models that list a range of times reactivated their alarm more slowly at low CO levels and faster at high levels. Since several models tested did not have reset buttons, they could not be rated.