$20 Co2 Sensor?? Anyone Seen This?

Yankee Rebel · 11th July 2007, 16:09

Gas Sensors

i saw this and got all excited!

im tired and an electronics idiot.. but can anyone do anything with that??? $20 and some fancy wiring? one of those PIC controllers or whatever those tiny porocessors and some programming that you guys do with HUDs?

CO2 is measured at X %... a BIG RED LIGHT starts flashing like a PI hooker... and a buzzer goes off????
can it be done?
an affordable diver friendly CO2 sensor?

the tech specs didnt load for me... but tell me.. will it work?

Yankee Rebel

Yankee Rebel · 11th July 2007, 16:50

crap im exhausted but cant sleep..
ok heres whats on my mind...

put the sensor in the scrubber.. on the scrubbed side of the stack... anything that goes thru the sorbstack SHOULD be below the ppm threshold thats set... remote wire it like a O2 cell with cable glands etc.
the controller for it and battery.. put into a pod like an ECCR... wouldnt have to take up more room than a beer can?
hygrophobic(sp?) membrane acrossed the face of the cell if it is suceptible to moisture and humidity?

set it up so that at a given PPM, it starts the LED"s flashing.. one of those small buzzers in the electronics pod to buzz nice and loud.... kinda like the gouges on the fog line on the highway... wakes you right up...

thatd be the basic design right there.. programming would be simple.. just like a basic HUD.. except there is only one setting.. when that PPM threshold has ben reached it goes nuts.. when the CO2 drops down below that... it stops making a racket and raising hell.. that way if youre overbreathing the scrubber... when you stop.. it stops...

ok.. now that i got that off my chest and outta my head...

andif it works and is viable.. no commercial manufacturers may use it to profit without express permission!!!! lol

Yankee Rebel

Barrie Law · 11th July 2007, 17:08

Quote: (Originally Posted by Yankee Rebel)

crap im exhausted but cant sleep..
ok heres whats on my mind...

put the sensor in the scrubber.. on the scrubbed side of the stack... anything that goes thru the sorbstack SHOULD be below the ppm threshold thats set... remote wire it like a O2 cell with cable glands etc.
the controller for it and battery.. put into a pod like an ECCR... wouldnt have to take up more room than a beer can?
hygrophobic(sp?) membrane acrossed the face of the cell if it is suceptible to moisture and humidity?

set it up so that at a given PPM, it starts the LED"s flashing.. one of those small buzzers in the electronics pod to buzz nice and loud.... kinda like the gouges on the fog line on the highway... wakes you right up...

thatd be the basic design right there.. programming would be simple.. just like a basic HUD.. except there is only one setting.. when that PPM threshold has ben reached it goes nuts.. when the CO2 drops down below that... it stops making a racket and raising hell.. that way if youre overbreathing the scrubber... when you stop.. it stops...

ok.. now that i got that off my chest and outta my head...

andif it works and is viable.. no commercial manufacturers may use it to profit without express permission!!!! lol

Yankee Rebel

Hi Yankee Rebel,

Shoudn't you patent that before you go to bed...

Rebreathing Red · 11th July 2007, 17:27

Hey Yankee, the sensor has a heating element in it. This may be a problem in a high O2 environment since if it gets hot enough it could start a fire...

cramerdn · 11th July 2007, 18:17

It says its sensitive from 0-10,000 ppm but it doesn't say in waht increments. For instance if it reads in 5,000 ppm increments it may not really be too usefull. Now the alchohol sensor below it...

**nigelh** · 11th July 2007, 18:34

Quote: (Originally Posted by Rebreathing Red)

Hey Yankee, the sensor has a heating element in it. This may be a problem in a high O2 environment since if it gets hot enough it could start a fire...

The power consumption of over a watt worried me and the sub 60 second response time doesn't look good even though the graph is much faster.
However it's a chemical cell so it should be pp Sensitive.

Hey I make instruments.
A couple to play with can't hurt...
...unless it gases off something nasty.

gibbogeo · 11th July 2007, 22:01

Quote: (Originally Posted by cramerdn)

It says its sensitive from 0-10,000 ppm but it doesn't say in waht increments. For instance if it reads in 5,000 ppm increments it may not really be too usefull. Now the alchohol sensor below it...

Here:

CO2 Sensor

Show the output curve. Seems tome that below 350-400 ppm it give the same mV.

York · 12th July 2007, 09:07

Hrm, I think the expression commonly used is something like carriage before the horse?
Great that we know how to implement it once it works.

The sensor is based on the NASICON-reaction, which requires a high temperature. Therefore it has a heating element, and the screen and outer housing is mainly so you don't burn your fingers - probably not a good idea in an oxygen-rich environment. The heating requires A LOT of power, so battery consumption becomes an issue. Additionally, the chemically reaction involves oxygen, so changes in PO2 will probably affect the CO2-reading as well. I don't expect that this can be compensated using the reading from the O2-sensors, as these are not precise enough.
The sensor itself looks slightly different than in the spec-sheet (see picture below - been there, tried it)
As a result of the heat-dependency it is VERY sensitive to flow, or more precisely changes to flow. This is probably the biggest obstacle. Additionaly, the calibration changes with flow temperature, so calibrating it will get very frickly.
On top of all that, the sensor requires quite a long time to warm up even under ideal conditions - 15 minutes or so.
It's a neat little sensor, but I doubt we will see any application in rebreathers of this puppy.

Back to the drawing board ...

Joerg

undrh2o · 12th July 2007, 16:35

Have a look at Tom Rose's post in this thread http://www.rebreatherworld.com/cells...nsor-dema.html

11th July 2007, 16:09	#1 (permalink)
Yankee Rebel Custom Title Allowed! Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: Jan 2006 Location: California Posts: 147	$20 Co2 Sensor?? Anyone Seen This? Gas Sensors i saw this and got all excited! im tired and an electronics idiot.. but can anyone do anything with that??? $20 and some fancy wiring? one of those PIC controllers or whatever those tiny porocessors and some programming that you guys do with HUDs? CO2 is measured at X %... a BIG RED LIGHT starts flashing like a PI hooker... and a buzzer goes off???? can it be done? an affordable diver friendly CO2 sensor? the tech specs didnt load for me... but tell me.. will it work? Yankee Rebel
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11th July 2007, 16:50	#2 (permalink)
Yankee Rebel Custom Title Allowed! Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: Jan 2006 Location: California Posts: 147	Re: $20 Co2 Sensor?? Anyone Seen This? crap im exhausted but cant sleep.. ok heres whats on my mind... put the sensor in the scrubber.. on the scrubbed side of the stack... anything that goes thru the sorbstack SHOULD be below the ppm threshold thats set... remote wire it like a O2 cell with cable glands etc. the controller for it and battery.. put into a pod like an ECCR... wouldnt have to take up more room than a beer can? hygrophobic(sp?) membrane acrossed the face of the cell if it is suceptible to moisture and humidity? set it up so that at a given PPM, it starts the LED"s flashing.. one of those small buzzers in the electronics pod to buzz nice and loud.... kinda like the gouges on the fog line on the highway... wakes you right up... thatd be the basic design right there.. programming would be simple.. just like a basic HUD.. except there is only one setting.. when that PPM threshold has ben reached it goes nuts.. when the CO2 drops down below that... it stops making a racket and raising hell.. that way if youre overbreathing the scrubber... when you stop.. it stops... ok.. now that i got that off my chest and outta my head... andif it works and is viable.. no commercial manufacturers may use it to profit without express permission!!!! lol Yankee Rebel
(Offline)

11th July 2007, 17:08	#3 (permalink)
Barrie Law Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jun 2005 Location: Ireland Posts: 459	Re: $20 Co2 Sensor?? Anyone Seen This? Quote: (Originally Posted by Yankee Rebel) crap im exhausted but cant sleep.. ok heres whats on my mind... put the sensor in the scrubber.. on the scrubbed side of the stack... anything that goes thru the sorbstack SHOULD be below the ppm threshold thats set... remote wire it like a O2 cell with cable glands etc. the controller for it and battery.. put into a pod like an ECCR... wouldnt have to take up more room than a beer can? hygrophobic(sp?) membrane acrossed the face of the cell if it is suceptible to moisture and humidity? set it up so that at a given PPM, it starts the LED"s flashing.. one of those small buzzers in the electronics pod to buzz nice and loud.... kinda like the gouges on the fog line on the highway... wakes you right up... thatd be the basic design right there.. programming would be simple.. just like a basic HUD.. except there is only one setting.. when that PPM threshold has ben reached it goes nuts.. when the CO2 drops down below that... it stops making a racket and raising hell.. that way if youre overbreathing the scrubber... when you stop.. it stops... ok.. now that i got that off my chest and outta my head... andif it works and is viable.. no commercial manufacturers may use it to profit without express permission!!!! lol Yankee Rebel Hi Yankee Rebel, Shoudn't you patent that before you go to bed...
(Offline)

11th July 2007, 17:27	#4 (permalink)
Rebreathing Red RBW Member Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Jun 2007 Location: North Carolina Posts: 24	Re: $20 Co2 Sensor?? Anyone Seen This? Hey Yankee, the sensor has a heating element in it. This may be a problem in a high O2 environment since if it gets hot enough it could start a fire...
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11th July 2007, 18:17	#5 (permalink)
cramerdn Obey my dog! Current Rebreather/s: Evolution Dolphin Other Rebreather/s: Dolphin Join Date: Dec 2006 Location: Townsville QLD Posts: 730	Re: $20 Co2 Sensor?? Anyone Seen This? It says its sensitive from 0-10,000 ppm but it doesn't say in waht increments. For instance if it reads in 5,000 ppm increments it may not really be too usefull. Now the alchohol sensor below it... __________________ "Its better to live one day as a tiger than an entire life as a worm." "But who's ever heard of a worm skin rug?"
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11th July 2007, 18:34	#6 (permalink)
nigelh New member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 883	Re: $20 Co2 Sensor?? Anyone Seen This? Quote: (Originally Posted by Rebreathing Red) Hey Yankee, the sensor has a heating element in it. This may be a problem in a high O2 environment since if it gets hot enough it could start a fire... The power consumption of over a watt worried me and the sub 60 second response time doesn't look good even though the graph is much faster. However it's a chemical cell so it should be pp Sensitive. Hey I make instruments. A couple to play with can't hurt... ...unless it gases off something nasty. __________________ nigelh
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11th July 2007, 22:01	#7 (permalink)
gibbogeo Gilberto Bonaga, Italy Current Rebreather/s: Classic Kiss Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Sep 2005 Location: italy Posts: 332	Re: $20 Co2 Sensor?? Anyone Seen This? Quote: (Originally Posted by cramerdn) It says its sensitive from 0-10,000 ppm but it doesn't say in waht increments. For instance if it reads in 5,000 ppm increments it may not really be too usefull. Now the alchohol sensor below it... Here: CO2 Sensor Show the output curve. Seems tome that below 350-400 ppm it give the same mV.
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12th July 2007, 16:35	#9 (permalink)
undrh2o Chris Miller Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Join Date: Apr 2006 Location: Ottawa, Canada Posts: 206	Re: $20 Co2 Sensor?? Anyone Seen This? Have a look at Tom Rose's post in this thread http://www.rebreatherworld.com/cells...nsor-dema.html
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