A neat side effect of these units is when you have a leaky cabin heat manifold and gets CO into the cabin. You will get very high SaO2 values when exposed to CO. An addition to safety when interpreted right.
You should always have a CO monitor. I have a BW Gasalert – not cheap but really good, and even picks up the gases from the plane which landed before you. The battery lasts a year or two.
The paper patches most people fly with are rubbish. You will be half dead by the time it changes colour, and anyway it is silent.
Thanks for the hints and tips – I hadn’t considered the orientation of the device at all.
Will try a fairly inexpensive one and see whether it tells me I am still alive or not!
I don’t think the orientation is an issue. I have one of each type. You just bend your finger over 
Peter wrote:
I don’t think the orientation is an issue. I have one of each type. You just bend your finger over
Sure, but then it easily slips off and it’s uncomfortable. Much better to be able to read it right side up!
@Magnus: thanks for the tip. I was preparing an order there so have added this item. Suggestions for tests/verification welcome, when it has arrived. I reckon the first one will be to watch what happens when standing/breathing close to an active exhaust…
The first one will be to see if you get any reading in the air because it’s the same I have and doesn’t work reliably (see comment above).
Aarrggh! I really must learn to read more carefully. Thanks for the warning, Vladimir.
You might be lucky and yours might work better. It’s still only a couple of bucks, so you can give it a try.
