I had a transitory 80ppm reading a few days ago. The detector (a Pocket CO 300) just had its sensor replaced a few weeks ago. I dismissed it as a sensor fluke, especially since it went way down after only a dozen of seconds or so.
These days, I wear the detector attached to my belt semi-permanently.
I was waiting for my IFR slot on the ground, in the plane, engine off, at a small nice grass airfield where I may have been the only movement of the day (and certainly no movement at least half an hour before the event). Suddenly the detector alarms.
The only reason I can think is that the sensor was covered by a fold of my clothes and thus did not have access to actual air; somebody has expertise on how the sensor works and if isolation can create a false positive? Maybe it overheated?
Well, the news from the Sala/Ibbotson crash is salutary.
What is on the market as a really small portable CO detector? Something that could be clipped to flight bag?
I have one of these. These are high quality products. There is a lot of junk out there…
80ppm on the ground, while waiting, is very possible, with wind at just the right angle.
Probably another reason to lean really far on the ground; LOP mixtures don’t make CO 
Two identical threads merged.
Aviation pricing there!
I have a couple of these at home…
https://www.amazon.co.uk/gp/product/B00441S9GS/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
The sound is absolutely deafening and frankly, painful. I am confident I would hear it over the engine and while wearing a headset, so one will come with me next time I fly the TB10.
One thing I like about the BW GasAlert series is that I can set my own alert levels. Since “someone on the Internet” wrote that stuff above 10-20ppm in cruise should be diagnosed, I set that. Which meant it would regularly alert on the ground, when behind another aircraft, or on the runway when another aircraft just took of or landed.
The BW GasAlert is certainly small enough to be clipped to a flight bag, it even has a clip built in. Smallest I know are the Pocket CO and the Sparrow. The SAVCO is pretty small, too, and has a metal ring to be hung by.
It is not clear to me how the Sparrow alerts. If it makes sound through the paired pocket computer / smartphone through bluetooth through the headset, that’s good.
Peter wrote:
There is a lot of junk out there…
What about this one? https://www.kidde.com/home-safety/en/us/products/fire-safety/co-alarms/c3010d/
lionel wrote:
Which meant it would regularly alert on the ground, when behind another aircraft, or on the runway when another aircraft just took of or landed.
Probably a good test that it works…
Worth keeping in mind:
99p for four including postage is the non-aviation price.
25p each
(Sorry about all the edits, I couldn’t get the link to work on my phone)
@Timothy, 99p is for instructions only. A 4-pack actually costs 4.99 £. Multiple packs cheaper, but still not 25p a piece :)
More seriously, I don’t like how the alarm time is solidly in a two-digit amount of minutes at dangerous levels (50ppm, even 100ppm).
