Our test station is a custom built carbon monoxide detector. It’s one of the deadliest things we’ve ever put together in our product testing lab.
To test these detectors, we went to the lab and built a test rig designed to measure the response time of each unit at various concentrations of carbon monoxide, specifically at 250 ppm and 400 ppm. Our goal was to determine the effectiveness of each detector in detecting potentially dangerous levels of carbon monoxide. To announce our winners, we also considered factors that add to the overall user experience, performance and cost effectiveness of each unit.
With a concentration level of 250 ppm, we are trying to simulate a situation where carbon monoxide has started to accumulate to dangerous levels. We double-check this concentration and estimate the results. At 400 ppm, we replicate the worst-case scenario, a potentially dangerous scenario, and give units a pass or fail. Spoiler alert: All of them will save your life, which goes to show how important it is to have carbon monoxide detectors installed on every floor of your home.
This is one of the most dangerous experiments we have ever done. Carbon monoxide exposure is no joke. It’s almost invisible and, well, deadly. We needed to develop a safe way to test carbon monoxide detectors without endangering the health and safety of our laboratory staff. So I used my unusual carpentry skills and built a carbon monoxide test station. Its parts are:
Carbon monoxide detector room: It’s made of wood, plexiglass, silicon, tape and a bunch of finishing nails.
Carbon monoxide tank with gas flow regulator: A cylinder tank containing carbon monoxide at 2,500 ppm and balance air.
Testo 300 with carbon monoxide Ambient sensor: Our control device for this experiment.
Two portable carbon monoxide alarms.
A look inside CNET’s carbon monoxide test rig.
The room holds two carbon monoxide detectors, a) the CO Ambient sensor part of our control device, the Testo 300, which is a combustible material detector used by heating engineers who perform routine installation and maintenance of industrial and residential heating systems, and b) the unit under test, or UUT, which replaces each carbon monoxide detector we have tested for you. The chamber is sealed with foam but it is not airtight, because we are not particularly interested in making a carbon monoxide bomb.
We use a portable carbon monoxide alarm on the gas regulator to stop the leak.
We installed a gas flow regulator in our tank to prevent pressure build up, followed by a gas line to get our gas mixture into the chamber. Two portable carbon monoxide detectors are used. One near the valve, to ensure there are no leaks and the other to be worn by the tester to ensure there is no carbon monoxide buildup in the test station area. On top of all that, our respirators are compatible with high-ventilation environments, ensuring that we always get fresh air at all times. All of this may sound extreme, but it’s always good laboratory practice to put safety first, especially when dealing with a stealthy and powerful killer.
We start by supplying our gas mixture to the room and carefully monitor the concentration of carbon monoxide in Testo. If the concentration inside our room reaches at least 250 ppm or 400 ppm, we stop supplying gas and start the timer. We want to test how long carbon monoxide detectors take to react to those conditions. As you can understand, we wanted to minimize our exposure while making sure our results were repeatable.
Our results are summarized in the interactive graph below:
