CO2 meters

davy · 19th June 2006, 08:12

Hello,
I'm new to rebreathers (only have ~5 hours on various units to try them out)
And wondered why people are going to great lengths these days to find a means of measuring CO2 levels with temperature sticks etc. while there are portable CO2 meters commercially available?
A friend who is working in anesthesia commented that a so called "capnometer" is standard equipment in his field of work and is used in machines that look quite a lot like a rebreather.

Those capnometers are not big nor expensive ($600 range for a complete unit which would not be needed, just sensor and interface)
The sensor apparently is an infra-red sensor.
here is an example of one:
http://www.lintoninst.co.uk/capnometer.htm

I'm sure manufacturers are aware of these sensors etc.
so I'm wondering what is keeping them from using these sensors?

PCDiver · 19th June 2006, 08:30

Quote: (Originally Posted by davy)

Hello,
I'm new to rebreathers (only have ~5 hours on various units to try them out)
And wondered why people are going to great lengths these days to find a means of measuring CO2 levels with temperature sticks etc. while there are portable CO2 meters commercially available?
A friend who is working in anesthesia commented that a so called "capnometer" is standard equipment in his field of work and is used in machines that look quite a lot like a rebreather.

Those capnometers are not big nor expensive ($600 range for a complete unit which would not be needed, just sensor and interface)
The sensor apparently is an infra-red sensor.
here is an example of one:
http://www.lintoninst.co.uk/capnometer.htm

I'm sure manufacturers are aware of these sensors etc.
so I'm wondering what is keeping them from using these sensors?

The high humidity in the loop is creating problems for the IR sensors. This was discussed at length in several threads. If you do a search on this board you'll find lots of useful info on CO2 detection in rebreathers.

Peter

davy · 19th June 2006, 08:49

Ah yes, I see...
makes sense...

steevke · 19th June 2006, 10:02

You could solve that by adding a Peltier cooler (we do that when analysing flue gasses (Co2 and NOx) by IR sensors) but then you have the power consumption issue.

Steven

19th June 2006, 08:12	#1 (permalink)
davy New Member Current Rebreather/s: RB80 / Clone Home Build Other Rebreather/s: RB80 / Clone Home Build Join Date: Aug 2005 Location: Belgium Posts: 21	CO2 meters Hello, I'm new to rebreathers (only have ~5 hours on various units to try them out) And wondered why people are going to great lengths these days to find a means of measuring CO2 levels with temperature sticks etc. while there are portable CO2 meters commercially available? A friend who is working in anesthesia commented that a so called "capnometer" is standard equipment in his field of work and is used in machines that look quite a lot like a rebreather. Those capnometers are not big nor expensive ($600 range for a complete unit which would not be needed, just sensor and interface) The sensor apparently is an infra-red sensor. here is an example of one: http://www.lintoninst.co.uk/capnometer.htm I'm sure manufacturers are aware of these sensors etc. so I'm wondering what is keeping them from using these sensors?
(Offline)

19th June 2006, 08:30	#2 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 971	Re: CO2 meters Quote: (Originally Posted by davy) Hello, I'm new to rebreathers (only have ~5 hours on various units to try them out) And wondered why people are going to great lengths these days to find a means of measuring CO2 levels with temperature sticks etc. while there are portable CO2 meters commercially available? A friend who is working in anesthesia commented that a so called "capnometer" is standard equipment in his field of work and is used in machines that look quite a lot like a rebreather. Those capnometers are not big nor expensive ($600 range for a complete unit which would not be needed, just sensor and interface) The sensor apparently is an infra-red sensor. here is an example of one: http://www.lintoninst.co.uk/capnometer.htm I'm sure manufacturers are aware of these sensors etc. so I'm wondering what is keeping them from using these sensors? The high humidity in the loop is creating problems for the IR sensors. This was discussed at length in several threads. If you do a search on this board you'll find lots of useful info on CO2 detection in rebreathers. Peter
(Online)

19th June 2006, 08:49	#3 (permalink)
davy New Member Current Rebreather/s: RB80 / Clone Home Build Other Rebreather/s: RB80 / Clone Home Build Join Date: Aug 2005 Location: Belgium Posts: 21	Re: CO2 meters Ah yes, I see... makes sense...
(Offline)

19th June 2006, 10:02	#4 (permalink)
steevke Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Sport Kiss Join Date: Jul 2005 Location: Belgium Posts: 311	Re: CO2 meters You could solve that by adding a Peltier cooler (we do that when analysing flue gasses (Co2 and NOx) by IR sensors) but then you have the power consumption issue. Steven
(Offline)

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