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AD_ward9 · 5th October 2005, 08:35

Will we be using galvanic O2 sensors, and dual channel IR absorption CO2 sensing in 10 years time? I suggest not. What will replace it, and how can we make new designs user upgradeable to the new technology?

Other methods include potentiometric sensing, but these tend to require high temperatures. It is clear the winning technology will be sol-gel, probably just ink jet printed onto the end of the cartridge. A suitable light source then just reads the O2 and CO2 concentrations, by measuring either fluorescence or the quenching time of the fluorescence. Replacing the cartridge means replacing the sensors, but as they cost cents, who cares?

O2 and CO2 sensors are even being put on disposable food packaging using sol-gel technology. See http://www.osl.dcu.ie/projects/Intellipak/ and http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

The response time for some sol-gel optical technologies is about 10 times faster than the best existing sensors. For example work in the University of Southampton has produced a CO2 sensor with 1 second response times. See http://www.spie.org/web/abstracts/2200/2293.html.

There is work all around the world on sol-gels: they are not new technologies, but coupled with nano particles, gives a product which meets the commercial needs.

It is not just CO2 sensors using sol-gel techniques, but also O2: http://www.solgel.com/sgnews/templat...id=32&zoneid=3

So how do we future proof designs? Let us assume the sol-gel will win out over MEMs designs such as http://www.ornl.gov/sci/engineering_..._net_power.pdf
In this case, the module needed to read the sol-gel code can be interchanged with the CO2 sensing module.

In the Deep Life Open Revolution proposal, the scrubber stick would be replaced and a CO2 and O2 sensor reader using the CO2 port would be fitted. The scrubber stick is user replaceable (in fact, if something in it fails, the user can unplug it and the system still works but does not show CO2, He or scrubber health.

In terms of timescales, these sol-gel sensors may come into diving with the next couple of years. The result should be much more reliable O2 sensing, and CO2 sensing without any significant cost premium.

If the fluorescent wavelength is chosen appropriately, there should be no change with depth or pressure, greatly simplifying the task of CO2 sensing in a CCR.

Any better ideas for the future proofing, other than fit the new technology now?

Cheers,

Alex

5th October 2005, 08:35	#1 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,862	Disposable CO2 and O2 sensors Will we be using galvanic O2 sensors, and dual channel IR absorption CO2 sensing in 10 years time? I suggest not. What will replace it, and how can we make new designs user upgradeable to the new technology? Other methods include potentiometric sensing, but these tend to require high temperatures. It is clear the winning technology will be sol-gel, probably just ink jet printed onto the end of the cartridge. A suitable light source then just reads the O2 and CO2 concentrations, by measuring either fluorescence or the quenching time of the fluorescence. Replacing the cartridge means replacing the sensors, but as they cost cents, who cares? O2 and CO2 sensors are even being put on disposable food packaging using sol-gel technology. See http://www.osl.dcu.ie/projects/Intellipak/ and http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract The response time for some sol-gel optical technologies is about 10 times faster than the best existing sensors. For example work in the University of Southampton has produced a CO2 sensor with 1 second response times. See http://www.spie.org/web/abstracts/2200/2293.html. There is work all around the world on sol-gels: they are not new technologies, but coupled with nano particles, gives a product which meets the commercial needs. It is not just CO2 sensors using sol-gel techniques, but also O2: http://www.solgel.com/sgnews/templat...id=32&zoneid=3 So how do we future proof designs? Let us assume the sol-gel will win out over MEMs designs such as http://www.ornl.gov/sci/engineering_..._net_power.pdf In this case, the module needed to read the sol-gel code can be interchanged with the CO2 sensing module. In the Deep Life Open Revolution proposal, the scrubber stick would be replaced and a CO2 and O2 sensor reader using the CO2 port would be fitted. The scrubber stick is user replaceable (in fact, if something in it fails, the user can unplug it and the system still works but does not show CO2, He or scrubber health. In terms of timescales, these sol-gel sensors may come into diving with the next couple of years. The result should be much more reliable O2 sensing, and CO2 sensing without any significant cost premium. If the fluorescent wavelength is chosen appropriately, there should be no change with depth or pressure, greatly simplifying the task of CO2 sensing in a CCR. Any better ideas for the future proofing, other than fit the new technology now? Cheers, Alex
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