Carbon Monoxide detector

Just bought a CO detector - decent brand (Honeywell), brand new and looks well constructed. The self Test button works fine. I just thought though, that button tests the electronics and the beeper - but how about testing for real CO. So I put the detector near the exhaust pipe of my car (7-8 seconds). No CO detected - at least the alarm did not sound. Should it have?

If you have a catyalyser maybe not. You need to be careful you can bugger them up doing that I'm told. A cigarette is better. The test button BTW does not guarantee it's working, it tests the battery and part of the circuit.

Yes, that's why I tried the car.

I have a fireangel Carbon monoxide alarm, it has a test mode where you can activate it with either a cigarette or incense stick. Check the instructions, might have something similar

I just overdo the toast with the kitchen door open. It's never failed me yet....

Ah, actually, re-reading the thread title, that's the fire alarm. Oops.

Agreed, CO detectors appear to be rather delicate little flowers. I have heard that some ordinary household chemicals can "poison" the sensor.

CO is also a sort of cumulative toxin. So low levels for a long time can be just as bad as high levels for a short time. As a result they may not sound straight away unless the levels are very high.

Looks at documenation for our Ei208 CO detector. It effectively has 6 "alarm" states, derived from 3 level ranges of CO and time. At the lowest level it flashes its red light at 0.5 Hz and it takes 60 to 90 min before the sounder alarms, assuming the CO remains. Even at the highest level range it can take a couple of minutes before the sounder goes off.

Try your lawn mower.

We used to have a CO monitor in the lab where I worked. I tried testing it with a blast from a 'bottle' of CO, with no result. It didn't go off. I rang the manufacturers, and they said it required exposure over an extended period, about 30 minutes, to set it off. Yours may be similar.

That's where the Fireangel test mode comes in, it will set off the alarm if it senses 50ppm, with no exposure time limit