fun fact.
So I didn't want to send it back for the firmware update or calibration because it was very expensive and I've been largely unsatisfied with their level of customer service. Still can't believe they didn't design the thing to firmware flash via USB or through the app.
Doubt you'll see a response here, but I may be surprised.
If you want a down and dirty way, you can breathe into it and just tell it that it is a higher level of CO than you are putting into it. If you're a non-smoker you should be exhaling around 5ppm.
If you're a smoker, it will be somewhat higher than that, and conveniently somewhere around the 20ppm calibration gas.
Obviously that means you have a bogus calibration but since most of us use it as a "it's there, or it isn't", then whether it is 4ppm or 6ppm doesn't really matter.
Now. If you have a good relationship with your local fire department and they have a newer Bauer compressor *others may have it*. There should be both 0ppm and 20ppm calibration gas bottles, as well as a flow regulator inside of the compressor housing. Mine has the mini Unicus. In the picture below, you can see the door in the middle of the compressor. The two calibration bottles are on the wall between the compressor head and the fill station. They're white, you can't miss them.
The flow limiter and adapter to get onto those bottles is the same fitting as the mini coleman propane bottles so technically you could redneck engineer it with one of those and some air hose. The compressor should have that fitting inside it though, but it is hiding. In the unit we have, it is clipped in down by the CO monitor for this compressor. That is on the side door, by the bottom hinge, and about 6" in from the door. Kind of have to get on the floor and look in there to find it *don't do it with the compressor on*. Now you have free cal gas and flow limiter. That's how I do mine
