DIY 02 sensor

cstmwrks

Well I feel a little better having stirred the pot of history just a bit. Dave is right, there is no new discussions per say, just new people discussing it. I never got to speak with Walter Stark, only eMails and one call to the co inventer John Kanwisher who made the sensor. Dave pretty well hit the hammer on the head with a nail, guys like Walter have already forgotten more than most of us will ever know. Thats why my interest in the unit and the "old way" of doing things. Even guys like Will Smithers who knew alot about electronics and had NO problem letting people know that, had commented on the MK15 analog controller ( a 50's design as I recall ) as being one WELL thought out unit.

Skipbreather

A true teaching tool and valuable resource for hardware, technique, and historical perspective.... Let's hope Paul is inclined to put it back up soon. I just tried my 'Nuggets' link, and that one's completely dead.

Interesting how things go full circle. It wasn't all that long ago the 'List' was having some pointed discussion re whether or not it should be echoed (is that the right term?) here on RBW.

Remember this post from early 2005? :

Guys,
Are our posts to nwdesigns being snarfed and
cross posted to a web forum?
There seems to be posts being replied to here
that have never been sent to the list.
Would the administrator of RebreatherWorld
care to explain?
Mr Elliott? What's going on?

Thanks,
Jason.

Times change and communication techniques move on. It would appear "Grasshopper" has lept & flown beyond "Master". The goal remains unchanged: Rebreather divers helping other RB divers be safe and keep alive- all while having some occasionally lively fun in the process.

Ken

cstmwrks

Hi Ake,
The fog is slowly leaving my brain. I do have the patent drawings and now remember trying to figure out the value and type of thermister that was used in the sensor. There was the basic "r" value and the question of did it increase or decrease the R value with an increase in ambiant temp. I had a part number as I recall but could never get a cross ref to anything new. I know one can figure out what you need by building one and testing it but I wanted all the basic details of the original one. I had hoped that John Kanwisher would be kind enough to drop some details but I imagine I fell in the " if you have to ask how" then you should not do it catagory. So much for the short cut!

Bill

DanFountain

This link still works:

Index of /rebreathers/Nuggets

Skipbreather

Thanks! At least the "best of the best" is still there. I just checked the properties of my link and saw it was to the old metacut.com server. To quote Homer Simpson- "DOH!........."

Corallaro

I'm working, a lot slowly on the zinc-air cells,
at the momente the result are not costant.
I am not a great expert of electronics.
someone has made tests?

AD_ward9

Effort saving tip: Try testing them at PPO2 of 2.0 before you get excited.

Alex

Corallaro

I have tested them in a little trasparent homemade hyperbaric chamber with o2 and a ppo2 sensor with a m-03 IT cell att ppo2 of 1.9, beyond, i feared an outbreak.......

3 cells tested of the same confection but opened at different times

one of them works perfectly

two at ppo2 1,7 have a voltage fall

there are directly connected to an lm3914 in dot mode

cstmwrks

When I started this thread I was more in mind to see what the interest was in the polarographic sensor range. Not to bash any ones interest in expanding knowledge but I think the zinc air cells are bad voodoo. They may work like a fuel cell sensor but they are not made as one. The sensors the Electrolung used were for all practical purposes "hand made" and the ART of making and using them has been lost.
I think that enough of the right minds could re invent the wheel as a very viable means of monitoring PP02... for the extreme limited production assembler of course.