Cootwo CO sensor calibration

[Hatul]

My Cootwo is complaining that it needs the CO sensor calibrated. Anyone know if anyone still does that. Scubatude used to do it but they've closed.

Adam

 

[JohnN]

My Cootwo is complaining that it needs the CO sensor calibrated. Anyone know if anyone still does that. Scubatude used to do it but they've closed.

Adam

You can do it yourself. Depending if you have the "old" or "newer" firmware update on your COOTWO, you need either 10 ppm or 20 ppm CO calibration gas. The smallest cylinder looks like a propane torch cylinder.

I kludged together a fitting from a standard propane torch, plus a rubber radiator hose to fit over the inlet of the COOTWO. Crack the CO calibration gas, give it some time to saturate the interior of the COOTWO and you're off to the races.

 

[tbone1004]

If you're just looking for a go-nogo type you can calibrate against exhaled gas from your mouth. Set it to 10ppm and your body will be exhaling 1-4ppm of co if you're a non smoker. This will at least tell you if there is CO present even if the ppm isn't accurate.
Bump gas is available from a variety of sources though, I use the bump gas from a newer Bauer Compressor since they have CO sensors on the pumps themselves.

 

[Hatul]

You can do it yourself. Depending if you have the "old" or "newer" firmware update on your COOTWO, you need either 10 ppm or 20 ppm CO calibration gas. The smallest cylinder looks like a propane torch cylinder.

I kludged together a fitting from a standard propane torch, plus a rubber radiator hose to fit over the inlet of the COOTWO. Crack the CO calibration gas, give it some time to saturate the interior of the COOTWO and you're off to the races.

Looks like mine wants 20 PPM calibration gas. Can you point me to one that will take a propane torch fitting?

 

[JohnN]

Looks like mine wants 20 PPM calibration gas. Can you point me to one that will take a propane torch fitting?

Carbon Monoxide Calibration Gas CO 20 PPM Balance Air in a 17 Liter Steel Cylinder CGA 600 Connection

Carbon Monoxide Calibration Gas CO 20 PPM Balance Air in a 17 Liter Steel Cylinder

www.calgasdirect.com

 

[Hatul]

With shipping it's $83.48. The CO sensor is over a year old now and I wonder if I'm better off buying a new Sensorcon for $177

 

[Tracy]

Does anybody have a copy of the iphone app? It isn't available anymore. I have plenty of bump gas, but no way to calibrate it.

 

[Hatul]

Does anybody have a copy of the iphone app? It isn't available anymore. I have plenty of bump gas, but no way to calibrate it.

You can calibrate it without the app. Just use the menus on the device.

 

[undrwater]

With shipping it's $83.48. The CO sensor is over a year old now and I wonder if I'm better off buying a new Sensorcon for $177

I think @DandyDon recently opined that the Sensorcon sensors are not ideal for scuba application.

 

[Tracy]

You can calibrate it without the app. Just use the menus on the device.

Yeah, it lets me do it, then when I turn it back on, it is locked out. If I pull the battery, it works one time again. I was hoping it was something I needed to do in the ap. I liked the cootwo, but it has been sitting on the shelf for years