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By Fellsteruk
#1815945
Hey all,

Any suggestions for a digital co2 monitor which is small enough to clip on my flight bag and decent enough to last me a few years.

Thanks
Last edited by Fellsteruk on Wed Dec 23, 2020 12:33 am, edited 1 time in total.
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By GrahamB
FLYER Club Member  FLYER Club Member
#1815959
I bought one of these eighteen months ago.

This one comes with a plastic mounting tray, but you can find the same thing with a lanyard. It developed a fault quite soon after I started using it, but to their credit the suppliers replaced it FOC very quickly. The replacement has worked fine since then.

It will detect very low levels of CO, down to 9 ppm. The most I've ever seen it go to in flight was 30ppm, in a long climb. I put that down to airflow rather than a leaking exhaust system, and that concentration is way below any dangerous level. You can check them by standing behind an aircraft when it starts up and is running rich.

Top tip - lean your mixture as much as you can in all phases of flight, including on the ground. The leaner the mixture, the less CO is produced. If you can run your engine lean of peak, almost no CO is generated.
By Fellsteruk
#1815969
Great thanks I’ll check that out.

I love how it’s likely got the same or similar guys for a £15 B&Q detector but a nicer and smaller form factor and they are like, “wait, wat, they willl use this in aviation, $100 it is...” :)

Not able to lean mixture as I’m still using school aircraft and that’s not something they teach, to be fair I’ve never asked but I will on next flight as mixture it always rich.

I suspect they don’t want students getting it wrong and at best damage to engine or worse they lean a little too much and cutoff the fuel, panic and end up in a ditch.

One for when I get my own set of wings :)
By riverrock
FLYER Club Member  FLYER Club Member
#1815999
One to ask your instructors about.

On CO - my understanding is that non- certified one will alarm as soon as it detects a level. The certified ones alarm at a higher level, or a lower level for a period of time.
Do know the numbers. Small bursts of CO at lower levels are normal. I wouldn't wanting you t be making an emergency landing unnecessarily ( which is one of the risks of those meters).

I like the FireAngel ones which show a graph of build up:
https://www.amazon.co.uk/Fireangel-CO-9 ... B00441S9GS
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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1816025
Fellsteruk wrote:One for when I get my own set of wings :)


The school should be teaching you leaning whenever you're out of the circuit.

If they're not, ask them, they should be, both for keeping the engine healthy and not coked up and keeping the fuel bills down. Flying full rich is like flying with the choke on.
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By Dusty_B
FLYER Club Member  FLYER Club Member
#1816062
Fellsteruk wrote:Not able to lean mixture as I’m still using school aircraft and that’s not something they teach, to be fair I’ve never asked but I will on next flight as mixture it always rich.


It should be part of exercise 4b, effects of controls.... and exercise 6b, straight and level flight! Not all aircraft have mixture controls though (see Rotax, eg).
#1816318
The question that no-one seems to be able to answer is what do you do with these B&Q type CO monitors when the thing goes off?...and most of them make quite a racket!
The ones I have seen do not have an off switch so the only way to stop it bleating away is to take the batteries out. Not something I want to be doing is trying to shut something like a bleating CO monitor when flying say on final approach, or in a busy circuit.
By rdfb
#1816389
riverrock wrote:On CO - my understanding is that non- certified one will alarm as soon as it detects a level. The certified ones alarm at a higher level, or a lower level for a period of time.
Do know the numbers. Small bursts of CO at lower levels are normal. I wouldn't wanting you t be making an emergency landing unnecessarily ( which is one of the risks of those meters).

I like the FireAngel ones which show a graph of build up:
https://www.amazon.co.uk/Fireangel-CO-9 ... B00441S9GS


I have a FireAngel CO-9D too. It also displays the detected PPM level (if it's above 10) and won't go off just for 11 PPM or whatever. The user manual is pretty specific about alert levels. It will go off in:
  • Between 60 and 90 minutes when exposed to a minimum of 50ppm CO.
  • Between 10 and 40 minutes when exposed to a minimum of 100ppm CO.
  • Within 3 minutes when exposed to a minimum of 300ppm CO.

This is apparently a European standard.

Shoestring Flyer wrote:The question that no-one seems to be able to answer is what do you do with these B&Q type CO monitors when the thing goes off?...and most of them make quite a racket!


According to the FireAngel CO-9D manual:

It is possible to temporarily silence the alarm up to two times if the level of CO that triggered the alarm is less than 200ppm...

The silence mode will last for up to 3 minutes. If the CO level remains too high the alarm will trigger again or if the level of CO rises above 200ppm then the detector will automatically re-enter alarm mode. If the level of CO has fallen to a satisfactory level the silence mode icon will disappear, the unit will exit alarm mode...


I'm OK with this. An unstoppable alarm will be a pain, but better than me dying. If I have to land with a "radio failure" because I can't hear anything then so be it. For £19 every seven years it's worth having, but if somebody wants to spend more to have a silence-able alarm then sure, do that. Please just get something, even this, rather than nothing.

I made a 3D printed mount for this particular device if anyone wants one.
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#1816476
I've also got a Fireangel 9D. I've added a small toggle switch in the side of the case so I can just turn it off. If you've got a problem, the last thing you need while you are sorting it, is an alarm going off!
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