Co2 Sensor At Dema

decoweenie · 11th December 2006, 20:21

Quote: (Originally Posted by Tom Rose)

My target date of availability of a commercial system is Spring of 2007...

Tom,

Great job!

To be honest, I personally thought your sensor would not be the first commercially available when considering the competitions. But looks like I will be wrong - and very glad that I am too...

jaap · 11th December 2006, 20:27

[quote=Tom Rose;82793]

Quote: (Originally Posted by jaap)

A NDIR system "counts" the molecules of CO2 in the gas path....the greater the number of CO2 molecules the less signal to the detector....the number of molecules in the path is due to a combination of proportion of CO2 and pressure. Regardless, you cannot tolerate but so high a percentage of CO2 molecules in the gas mix reported as if it was at the surface.

Therefore it does not care about pressure or concentration. It just tells you the absolute amount of CO2 in the IR path.

Just like oxygen....pure oxygen at the surface is not a real problem to breath....but take that pure oxygen to 100 feet and we have a problem...houston control

We certainly do not want to breath CO2 levels of 5% at the surface or at 130 feet breath 1% CO2. Fortunatly properly working scrubbers keep the CO2 at lower and lower percentage as depth increases.

Hope this helps,
Tom

So what you are saying is that the signal is proportional to the pCO2, yes?

So no depth sensor is required to get a reading of the pCO2, yes?

After all pCO2 (or SEV-%CO2 if that sort of number feels better) is what matters.

Genesis · 11th December 2006, 21:02

Any guesses on end-user-style pricing?

divetheworld · 11th December 2006, 21:11

[quote=Tom Rose;82793]

Quote: (Originally Posted by jaap)

A NDIR system "counts" the molecules of CO2 in the gas path....the greater the number of CO2 molecules the less signal to the detector....the number of molecules in the path is due to a combination of proportion of CO2 and pressure. Regardless, you cannot tolerate but so high a percentage of CO2 molecules in the gas mix reported as if it was at the surface.

Therefore it does not care about pressure or concentration. It just tells you the absolute amount of CO2 in the IR path.

Just like oxygen....pure oxygen at the surface is not a real problem to breath....but take that pure oxygen to 100 feet and we have a problem...houston control

We certainly do not want to breath CO2 levels of 5% at the surface or at 130 feet breath 1% CO2. Fortunatly properly working scrubbers keep the CO2 at lower and lower percentage as depth increases.

Hope this helps,
Tom

Question, am I missing something?
If you are using an IR absorb sensor then it will be specific to a frequency, but that frequency will change with pressure.
So as the pressure increases so will the error. IR is usually only accurate over a specific range.

Brent

RZEP17 · 16th December 2006, 14:10

Tom,
Thx a lot for the info - very interesting. Can't wait for the final product.
\rgrds
Tomek

Tom Mount · 16th December 2006, 15:02

[quote=Tom Rose;82793]

Quote: (Originally Posted by jaap)

A NDIR system "counts" the molecules of CO2 in the gas path....the greater the number of CO2 molecules the less signal to the detector....the number of molecules in the path is due to a combination of proportion of CO2 and pressure. Regardless, you cannot tolerate but so high a percentage of CO2 molecules in the gas mix reported as if it was at the surface.

Therefore it does not care about pressure or concentration. It just tells you the absolute amount of CO2 in the IR path.

Just like oxygen....pure oxygen at the surface is not a real problem to breath....but take that pure oxygen to 100 feet and we have a problem...houston control

We certainly do not want to breath CO2 levels of 5% at the surface or at 130 feet breath 1% CO2. Fortunatly properly working scrubbers keep the CO2 at lower and lower percentage as depth increases.

Hope this helps,
Tom

Hi Tom

You know that Tomar (Titan- bubbleseekers) also had a co2 sensor at DEMA plus waterproof o2 sensors- not sure how or if your designs are similar

RZEP17 · 17th December 2006, 16:35

Hi again
Some more questions for Tom Rose.
Being so informative, about your device, I hope you don't mind few more questions, Tom.

The O2 drying flow - you have to find a compromise between drawing adequate gas sample for monitoring CO2 and still not affecting to much the PPO2 in the loop. Is there a potential for the hyperoxia in certain situation like rapid decent? And again my understanding is you are using some kind of orifice/ venturi tube in your aspirator. Is there potential, pardon my language, for sucking in some sorb dust and plugging it? Finally the mysterious(for me) membrane open for water vapors and impenetrable for the CO2 molecules. Can you say something more about it or it is a trade secret?
rgrds
Tomek

Tom Rose · 20th January 2007, 12:33

Just a short progress report. I am still on schedule for a spring release.

Pressure proofing of the detector appears to be successful...

I have had offers for testing in two chambers that each have wet testing capabilities.

I have posted an update of the specifications for general viewing on my atlimp website. It reflects a number of questions asked at DEMA and since.

http://www.atlimp.com/co2/co2%20moni...20jan%2007.pdf

You can see the cell at

http://www.atlimp.com/cell.jpg

Regards
Tom

Genesis · 20th January 2007, 13:11

Niiiiccceeeee... any idea on how this is going to price out yet?

**Padipro** · 14th July 2007, 02:40

Any new information on the sensor Tom? We are well into summer 2007 now and I'm sure I'm not the only one interested to hear when this will be available and what it will cost.

Thanks

11th December 2006, 20:21	#11 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Re: Co2 Sensor At Dema Quote: (Originally Posted by Tom Rose) My target date of availability of a commercial system is Spring of 2007... Tom, Great job! To be honest, I personally thought your sensor would not be the first commercially available when considering the competitions. But looks like I will be wrong - and very glad that I am too... __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
(Offline)

11th December 2006, 20:27	#12 (permalink)
jaap Normal people worry me Current Rebreather/s: Classic Kiss Other CCR RB80 / Clone Ray Other SCR Home Build Other Rebreather/s: Other CCR RB80 / Clone Ray Other SCR Home Build Join Date: Jun 2005 Location: Stockholm Sweden Posts: 438	Re: Co2 Sensor At Dema [quote=Tom Rose;82793] Quote: (Originally Posted by jaap) A NDIR system "counts" the molecules of CO2 in the gas path....the greater the number of CO2 molecules the less signal to the detector....the number of molecules in the path is due to a combination of proportion of CO2 and pressure. Regardless, you cannot tolerate but so high a percentage of CO2 molecules in the gas mix reported as if it was at the surface. Therefore it does not care about pressure or concentration. It just tells you the absolute amount of CO2 in the IR path. Just like oxygen....pure oxygen at the surface is not a real problem to breath....but take that pure oxygen to 100 feet and we have a problem...houston control We certainly do not want to breath CO2 levels of 5% at the surface or at 130 feet breath 1% CO2. Fortunatly properly working scrubbers keep the CO2 at lower and lower percentage as depth increases. Hope this helps, Tom So what you are saying is that the signal is proportional to the pCO2, yes? So no depth sensor is required to get a reading of the pCO2, yes? After all pCO2 (or SEV-%CO2 if that sort of number feels better) is what matters. __________________ My initials: JAAP
(Offline)

11th December 2006, 21:02	#13 (permalink)
Genesis Bubbless Box of Death Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Oct 2005 Location: Sunny Florida Posts: 1,394	Re: Co2 Sensor At Dema Any guesses on end-user-style pricing? __________________ "A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American." http://www.denninger.net http://www.diversunion.org/liability.htm - Fix the Diving Cert racket
(Offline)

11th December 2006, 21:11	#14 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,535	Re: Co2 Sensor At Dema [quote=Tom Rose;82793] Quote: (Originally Posted by jaap) A NDIR system "counts" the molecules of CO2 in the gas path....the greater the number of CO2 molecules the less signal to the detector....the number of molecules in the path is due to a combination of proportion of CO2 and pressure. Regardless, you cannot tolerate but so high a percentage of CO2 molecules in the gas mix reported as if it was at the surface. Therefore it does not care about pressure or concentration. It just tells you the absolute amount of CO2 in the IR path. Just like oxygen....pure oxygen at the surface is not a real problem to breath....but take that pure oxygen to 100 feet and we have a problem...houston control We certainly do not want to breath CO2 levels of 5% at the surface or at 130 feet breath 1% CO2. Fortunatly properly working scrubbers keep the CO2 at lower and lower percentage as depth increases. Hope this helps, Tom Question, am I missing something? If you are using an IR absorb sensor then it will be specific to a frequency, but that frequency will change with pressure. So as the pressure increases so will the error. IR is usually only accurate over a specific range. Brent __________________ Self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. CHECK OUT OUR INTERWEBS FOR CUSTOM REBREATHER UPGRADES *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Last edited by divetheworld : 11th December 2006 at 21:17.
(Offline)

16th December 2006, 14:10	#15 (permalink)
RZEP17 New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Oct 2005 Location: Connecticut, USA Posts: 72	Re: Co2 Sensor At Dema Tom, Thx a lot for the info - very interesting. Can't wait for the final product. \rgrds Tomek
(Offline)

16th December 2006, 15:02	#16 (permalink)
Tom Mount New Member Current Rebreather/s: Inspiration Classic Evolution Megalodon Sport Kiss Classic Kiss Optima Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: USA Posts: 96	Re: Co2 Sensor At Dema [quote=Tom Rose;82793] Quote: (Originally Posted by jaap) A NDIR system "counts" the molecules of CO2 in the gas path....the greater the number of CO2 molecules the less signal to the detector....the number of molecules in the path is due to a combination of proportion of CO2 and pressure. Regardless, you cannot tolerate but so high a percentage of CO2 molecules in the gas mix reported as if it was at the surface. Therefore it does not care about pressure or concentration. It just tells you the absolute amount of CO2 in the IR path. Just like oxygen....pure oxygen at the surface is not a real problem to breath....but take that pure oxygen to 100 feet and we have a problem...houston control We certainly do not want to breath CO2 levels of 5% at the surface or at 130 feet breath 1% CO2. Fortunatly properly working scrubbers keep the CO2 at lower and lower percentage as depth increases. Hope this helps, Tom Hi Tom You know that Tomar (Titan- bubbleseekers) also had a co2 sensor at DEMA plus waterproof o2 sensors- not sure how or if your designs are similar
(Offline)

17th December 2006, 16:35	#17 (permalink)
RZEP17 New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Oct 2005 Location: Connecticut, USA Posts: 72	Re: Co2 Sensor At Dema Hi again Some more questions for Tom Rose. Being so informative, about your device, I hope you don't mind few more questions, Tom. The O2 drying flow - you have to find a compromise between drawing adequate gas sample for monitoring CO2 and still not affecting to much the PPO2 in the loop. Is there a potential for the hyperoxia in certain situation like rapid decent? And again my understanding is you are using some kind of orifice/ venturi tube in your aspirator. Is there potential, pardon my language, for sucking in some sorb dust and plugging it? Finally the mysterious(for me) membrane open for water vapors and impenetrable for the CO2 molecules. Can you say something more about it or it is a trade secret? rgrds Tomek
(Offline)

20th January 2007, 12:33	#18 (permalink)
Tom Rose Still Learning Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Prism Topaz Other CCR Home Build Join Date: Oct 2005 Location: USA,North Carolina Posts: 329	Re: Co2 Sensor At Dema Just a short progress report. I am still on schedule for a spring release. Pressure proofing of the detector appears to be successful... I have had offers for testing in two chambers that each have wet testing capabilities. I have posted an update of the specifications for general viewing on my atlimp website. It reflects a number of questions asked at DEMA and since. http://www.atlimp.com/co2/co2%20moni...20jan%2007.pdf You can see the cell at http://www.atlimp.com/cell.jpg Regards Tom __________________ The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time. www.atlimp.com
(Offline)

20th January 2007, 13:11	#19 (permalink)
Genesis Bubbless Box of Death Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Oct 2005 Location: Sunny Florida Posts: 1,394	Re: Co2 Sensor At Dema Niiiiccceeeee... any idea on how this is going to price out yet? __________________ "A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American." http://www.denninger.net http://www.diversunion.org/liability.htm - Fix the Diving Cert racket
(Offline)

14th July 2007, 02:40	#20 (permalink)
Padipro Supporting Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Nov 2006 Location: South Florida Posts: 209	Re: Co2 Sensor At Dema Any new information on the sensor Tom? We are well into summer 2007 now and I'm sure I'm not the only one interested to hear when this will be available and what it will cost. Thanks __________________ Scott IANTD Megalodon IANTD Trimix TDI Adv Nitrox and Deco PADI MSDT It could be that the sole purpose of your life is only to serve as a warning to others. Before you attempt to beat the odds, be sure you could survive the odds beating you.
(Offline)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode