Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm with LEDs, Test-Reset Button, Low Battery Indicator, Portable

Attractive; Easy to Activate; Detects and Alarms Appropriately. I always read the 1 star reviews before buying a product. Some disturbing comments were: “batteries are impossible to insert” — I had no trouble inserting the batteries (fit firmly but install with gentle pressure); “Tested with CO and got NO Audible Alarm” — this was a big red flag, so I tested my unit upon activation. At 500+ ppm CO got good LED visible readout, but NO audible alarm. Was ready to repackage and return, but re-read the product information sheet: “This alarm measures the exposure to carbon monoxide over time; it is designed to sound at 85 decibels at 10 feet when it detects 70 ppm (parts per million) of CO for 60 to 240 minutes, 150 ppm for 10 to 50 minutes, or 400 ppm for 4 to 15 minutes.” I retested, exposing unit to 400-650 ppm CO and got an audible alarm at around 6 minutes. Removal from source, display returned to zero and audible alarm ceased. Much more assured that the unit works properly. And Audible Alarm times are well within guidelines for exposure to CO and symptom development (see photo). Also really like that I can replace batteries. Previous units with sealed batteries didn’t last anywhere near the 10 year “useable life” advertised.

With emergency products like CO detectors, it’s hard to know if they really work unless you’re actually being exposed to dangerous amounts of CO. And if a CO detector doesn’t work, you wouldn’t know; instead, you’d just be poisoned while thinking that nothing was wrong. The only way to really find out if it works is to put it in an airtight container and generate CO.Because I like to play with dangerous chemicals at home, I decided to try this out. Adding formic acid to concentrated sulfuric acid causes the formic acid (HCOOH) to break down into CO and H2O. I got both of these chemicals for less than $10/liter apiece, plus shipping. I put some sulfuric acid into a graduated cylinder and placed it in a 1-gallon airtight plastic container. I then added small amounts of diluted formic acid and rapidly closed the container.Sure enough, it worked! It registered CO concentrations that were well within the ballpark of what I’d expect to get with the amount of formic acid I added (using the ideal gas law to figure out what the maximum CO level would be). In high concentration tests, I found that the alarm goes off within 3 minutes of hitting 500 ppm (which is dangerous but would take several hours to kill, giving plenty of time to get to fresh air). In another test, it went off after about 20 minutes of CO levels around 190 ppm, which is dangerous but not lethal. Its peak reading is in the 910-920 ppm range; it doesn’t display levels higher than that. Needless to say, it goes off within a minute or two of such high CO levels and anybody who sees 900+ ppm on the display should leave their house and seek medical help immediately.It worked well in low concentration tests too. Due to some strange US regulation, it displays “0” for any reading below 30 ppm. If you press the “peak level” button, though, it will tell you what its peak reading was even if it was below 30 ppm. This works down to the 10-15 ppm range, below which you don’t really have to worry about CO at all. Prolonged exposure around 50 ppm leads to an alarm after a couple of hours.Another, simpler test (which anyone with a CO detector should do to make sure it’s working) is to light a candle in an enclosed container with the CO detector, then close the container. The candle will burn through the available oxygen and a fair amount of incomplete combustion (releasing CO instead of CO2) will occur as it runs out of O2. I tried this and got 96 ppm with a small candle in my gallon container; a larger candle would probably release more. I then tried it by lighting a crumpled piece of newspaper in the container and got >910 ppm, which is reasonable because paper and wood experience pyrolysis, which releases lots of CO. Combustion of small amounts of acetone (a fairly clean fuel relative to paper) resulted in 300-550 ppm depending on how hot the fire got before I put the lid on; the lower reading relative to paper helps confirm that it’s reading accurately.In conclusion – this $20 detector works very well when tested with real CO. It’s accurate, the alarm goes off at dangerous CO levels, it only goes off if CO levels are dangerous, and it might just save your life.

this works good

I bought this because it will be easy to take on vacation, which I took to Mexico and it gave me piece of mind. It is battery operated. I just use it at home when not traveling.

A must have for homeowners
I have had these Kidde products before and they have lasted a very long time before they reach their “end of life.” I purchased this carbon monoxide detector to replace an older Kidde model and so far it has been tested and definitely works, let’s hope it never has to beep that loudly again. I recommend this Kidde carbon monoxide detector because it is battery operated and has a useful LCD screen to show relevant information. Mounting screws and batteries were included along with a manual that you should read as it has placement and function details.