Or you can use the DMD-3500B dpm also as described in Vance's Oxy Hacker's
Companion.  I built an analyzer with this meter and it works fine; perfectly
accurate compared to commercial units.

Available from www.circuittest.com, or more specifically:
http://www.circuittest.com/Default.asp?Main=/English/OnlineCat.asp?Menu=/Eng
lish/Content/Categories/CatM_C5.asp%26Detail=/English/Content/Items/DMD-3500
B.asp

Thirteen bucks, US.  It has not changed like the PM-128/A.

Cam

----- Original Message -----
From: "Patrick Duffy" <pduffy@al*.ne*>
To: <cobber@ma*.ci*.co*>; "Tech Diver" <techdiver@aquanaut.com>
Sent: Tuesday, February 29, 2000 2:06 AM
Subject: Re: O2 analyzer circuit board change.


> Jim,
>
> It is the same meter, but they have changed the format of the board and
> are now using the smaller rectangular resistors as opposed to the more
> commonly cylinder shaped, color coded ones.
>
> With the older version of the PM128, the O2 Hacker requires you to
> remove the blue resistor to the left of the pot.  With the new version
> of the PM128, you remove the "R3" resistor which is to the right of the
> existing pot.  The rest of the directions in the O2 Hacker remain the
> same.
>
> The trick to removing the new surface mounted resistors is to beat up
> one side and then quickly heat up the other side and "flick" it off the
> board.  They are quite small, so putting it back on will certainly take
> more patience.
>
> Patrick
>
>
> ===============
>
> > Thanks, Bob, I have updated the web site to reflect this information.
> >
> >   Jim
> >  -------------------------------------------------------------------
> >  Learn About Trimix at http://www.cisatlantic.com/trimix/
> >
> > > From: "Robert G. Rowlette"
> > > Date:  Thu, 24 Feb 2000 12:43:19 -0500
> > > To: "Chris Elmore"
> > > Cc:
> > > Subject: Re: O2 analyzer circuit board change.
> > >
> > > You evidently have a PM128A, not the orginal PM128 panel mount LCD
> > > millivolt meter that is specified in the article on Jim Cobb's web
site.
> > > The PM128A uses surface mount devices (SMDs) which are extemely
> > minatuture
> > > and really not easily changed. As recently as last November, I
purchased
> > an
> > > original PM128 - not A - from Parts Express in Dayton, OH. Check the
PE
> > web
> > > site @ ; they may still have some non-A
> > > PM128s left. Also, if I'm not mistaken, the newest version of Vance
> > > Harlow's "The Oxygen Hacker's Companion" deals with this issue.
> > >
> > > Good luck.
> > >
> > > Bob
> > >
> > > At 11:48 AM 2/24/2000 -0500, you wrote:
> > >> The plans on Jim Cobb's website
> > >   for making an
> > O2
> > > analyzer call for a PM128 circuit board. A new circuit board has
replaced
> > > the one illustrated on the website but the layout of the new one is
> > > completely different than the older one. I tried to contact Jim Owens
> > (who
> > > wrote the article) but my email bounced. If anyone knows how to reach
him
> > > or configure the new CB I'd really like to hear from them. Until this
> > gets
> > > figured out I'd caution people from buying the PM128 to make an O2
> > analyzer.
> > >> Thanks,
> > >> C.
> > >>
> > >>
> > >> Chris Elmore
> > >> College of Liberal Arts
> > >> Univ. of SC
> > >> (803) 777-1534 office
> > >> (803) 348-3055 mobile
> > >> Please use this address for all email: chris@sc*.ed*
> >
>
--
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