[JJ Campbell]

I have a small plane and there is CO leaking into the cabin.  I have a CO monitor and I can keep the level down to zero. Unfortunately, to do this I have to keep the two small portals in the side windows open. In the Summer this is not too bad but, in the Winter, I get very cold and uncomfortable.  For the last two years during my annual conditional inspections the aircraft mechanics have looked for and corrected any exhaust leaks they could find, or thought were suspect.  Sadly, the problem persists, and temperatures are dropping.

My question: is there anything (preferably an aerosol spray) that can make this invisible gas visible?

[Borek]

My question: is there anything (preferably an aerosol spray) that can make this invisible gas visible?

As far as I am aware: no.

[Enthalpy]

I wouldn't use a spray. Gas detectors exist, they are specific to one gas, you can buy the detector alone or with the associated electronics, simple (galvanometer output) or less (interface with a computer).

Then you let the detector sniff all parts from close distance, beginning with the exhaust pipes.

[JJ Campbell]

I wouldn't use a spray. Gas detectors exist, they are specific to one gas, you can buy the detector alone or with the associated electronics, simple (galvanometer output) or less (interface with a computer).

Then you let the detector sniff all parts from close distance, beginning with the exhaust pipes.

The only CO detectors that I can find are like the one I have which displays the PPM in my cabin.  I need something that will help me pinpoint the leak.  Is there a leak in the exhaust system?  Where? Is it exhaust gas that should be just harmlessly blowing away but is getting in the cabin? Where is the leak in the cabin?  None of the CO monitors that I have found can do this for me as far as I can tell.

[Borek]

I am afraid the only solution we can suggest is to use a portable detector (preferably with a sensor on a cable) and - on a running machine - patiently check every possible point. I am not aware of any other approach and lack of answers from others suggests they aren't aware of such a thing either.

[JJ Campbell]

I am afraid the only solution we can suggest is to use a portable detector (preferably with a sensor on a cable) and - on a running machine - patiently check every possible point. I am not aware of any other approach and lack of answers from others suggests they aren't aware of such a thing either.

I haven't found a monitor that has a sensor on a cable.  Does anyone know of one?

[Borek]

While there can be no portable detector that is dedicated to carbon monoxide, detectors used by people servicing gas equipment detect all flammable gases, and carbon monoxide is one of them.

Not sure if these detectors will work near a running engine, where there can be other unburnt volatiles present, but that's the only thing I can think of.

This is really a tough one, I feel your pain.

[Enthalpy]

I thought at the sensors, but even when googling for sensors, we get the complete detector with display and alarm. Here are some
https://www.conrad.com/search?search=Carbon%20monoxide%20sensor&searchType=regular
The ones at 30€ in a cylindrical metal can with 4-8 pins.
They are few mm small, you can put them at the end of a cable, but then you must probably build the rest of the electronics yourself.

Maybe you find a compound solution, where the small mobile sensor is at the end of a cable, and the display electronics belongs to the offer.

[JJ Campbell]

I thought at the sensors, but even when googling for sensors, we get the complete detector with display and alarm. Here are some
https://www.conrad.com/search?search=Carbon%20monoxide%20sensor&searchType=regular
The ones at 30€ in a cylindrical metal can with 4-8 pins.
They are few mm small, you can put them at the end of a cable, but then you must probably build the rest of the electronics yourself.

Maybe you find a compound solution, where the small mobile sensor is at the end of a cable, and the display electronics belongs to the offer.

Thanks.  I sent emails to 3 of manufacturers of the better Methane/Propane leak detectors asking for their advice/recommendations.  Fingers crossed...

[Enthalpy]

The sensors are quite specific. Their manufacturers make big efforts for that.

So if you want to detect CO, a methane or a propane gas detector won't fit.

[Hunter2]

Maybe this Youtube help

https://m.youtube.com/watch?v=RHTqMlW7RNI