Polarographic 02 Sensor Project

cstmwrks · 8th October 2006, 05:14

Found my book of notes from Walter and some patent drawings. Two small details I was attempting to find were the values of a 32A75 thermister. It has been guessed that the thermister was an NTC type. The other was the modern equivelent of a philbrick T-52 op amp. I have the info on the KOH formula, the original sorce for the silver and platinum and some hints and details that will be pretty useful should a set of these ever get made.
Bill

teknosofen · 10th October 2006, 11:46

Quote: (Originally Posted by cstmwrks)

Found my book of notes from Walter and some patent drawings. Two small details I was attempting to find were the values of a 32A75 thermister. It has been guessed that the thermister was an NTC type. The other was the modern equivelent of a philbrick T-52 op amp. I have the info on the KOH formula, the original sorce for the silver and platinum and some hints and details that will be pretty useful should a set of these ever get made.
Bill

Hi Bill!

I resend a piece of a mail you might recognize, see below, I hope mr Pease is still alive and well.

If you check the characteristics of the membrane, it is likely that the rate of diffusion will increase with increased temp (and thus the cell current at a given PO2), this ought to help you guessing if the thermistor is a NTC or PTC type.

Good Luck!

// Åke

>
> My colleague Rolf Castor says that the man who probably knows all
> about the old electronics parts is mr Bob Pease (rap@galaxy.nsc.com)
> who writes in the Electronic design magazine. He is presently touring
> Europe but my colleague got a prompt reply so he seems to be online.
> Mr Castors relaxed comment was that probably any reasonably good
> quality low bias OP-Amp will bo the job.
>
> The following is true for the galvanic fuel cells: The thermistor
> compensates for the effect of temperature on the diffusion of oxygen
> through the membrane. It is the membrane that limits the reaction
> process, not the chemistry itself. The result is that the resistor
> network and thermistor is tuned to the membrane characteristics. If
> this is true also for the polarographic cells, the exact value of the
> thermistor might not be that very interesting unless you find a very
> similar membrane to the Kanwisher/Stark one.
>
> Dr Gambert, the owner of http://www.it-wismar.de is a very
> knowledgeable person in electrochemistry and he might be willing to
> help you if you ask him, even though he makes most of his living from
> manufacturing galvanic cells.

DanFountain · 11th October 2006, 18:24

Quote: (Originally Posted by cstmwrks)

Found my book of notes from Walter and some patent drawings. Two small details I was attempting to find were the values of a 32A75 thermister. It has been guessed that the thermister was an NTC type. The other was the modern equivelent of a philbrick T-52 op amp. I have the info on the KOH formula, the original sorce for the silver and platinum and some hints and details that will be pretty useful should a set of these ever get made.
Bill

Bill,

Found the T52 opamp! philbrickarchive.org
Hope this helps.

Dan

8th October 2006, 05:14	#1 (permalink)
cstmwrks The old ways still work. Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Sep 2006 Location: Boise Idaho Posts: 238	Polarographic 02 Sensor Project Found my book of notes from Walter and some patent drawings. Two small details I was attempting to find were the values of a 32A75 thermister. It has been guessed that the thermister was an NTC type. The other was the modern equivelent of a philbrick T-52 op amp. I have the info on the KOH formula, the original sorce for the silver and platinum and some hints and details that will be pretty useful should a set of these ever get made. Bill
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10th October 2006, 11:46	#2 (permalink)
teknosofen Rebreather diver... Current Rebreather/s: Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet MK 15.X Other CCR Other SCR Home Build Join Date: May 2005 Location: Sweden Posts: 9	Re: Polarographic 02 Sensor Project Quote: (Originally Posted by cstmwrks) Found my book of notes from Walter and some patent drawings. Two small details I was attempting to find were the values of a 32A75 thermister. It has been guessed that the thermister was an NTC type. The other was the modern equivelent of a philbrick T-52 op amp. I have the info on the KOH formula, the original sorce for the silver and platinum and some hints and details that will be pretty useful should a set of these ever get made. Bill Hi Bill! I resend a piece of a mail you might recognize, see below, I hope mr Pease is still alive and well. If you check the characteristics of the membrane, it is likely that the rate of diffusion will increase with increased temp (and thus the cell current at a given PO2), this ought to help you guessing if the thermistor is a NTC or PTC type. Good Luck! // Åke > > My colleague Rolf Castor says that the man who probably knows all > about the old electronics parts is mr Bob Pease (rap@galaxy.nsc.com) > who writes in the Electronic design magazine. He is presently touring > Europe but my colleague got a prompt reply so he seems to be online. > Mr Castors relaxed comment was that probably any reasonably good > quality low bias OP-Amp will bo the job. > > The following is true for the galvanic fuel cells: The thermistor > compensates for the effect of temperature on the diffusion of oxygen > through the membrane. It is the membrane that limits the reaction > process, not the chemistry itself. The result is that the resistor > network and thermistor is tuned to the membrane characteristics. If > this is true also for the polarographic cells, the exact value of the > thermistor might not be that very interesting unless you find a very > similar membrane to the Kanwisher/Stark one. > > Dr Gambert, the owner of http://www.it-wismar.de is a very > knowledgeable person in electrochemistry and he might be willing to > help you if you ask him, even though he makes most of his living from > manufacturing galvanic cells.
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11th October 2006, 18:24	#3 (permalink)
DanFountain This is my custom title! Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Dec 2005 Location: Lake Superior Posts: 113	Re: Polarographic 02 Sensor Project Quote: (Originally Posted by cstmwrks) Found my book of notes from Walter and some patent drawings. Two small details I was attempting to find were the values of a 32A75 thermister. It has been guessed that the thermister was an NTC type. The other was the modern equivelent of a philbrick T-52 op amp. I have the info on the KOH formula, the original sorce for the silver and platinum and some hints and details that will be pretty useful should a set of these ever get made. Bill Bill, Found the T52 opamp! philbrickarchive.org Hope this helps. Dan Last edited by DanFountain : 11th October 2006 at 18:35. Reason: Wrong link!
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