Dear all,


It would seem the physical approach scored (see below).


Cheers,

Wolfram

> -----Original Message-----
> From: Sunita R Shah [mailto:[log in to unmask]]
> Sent: 18 June 2004 20:35
> To: Dr W Meier-Augenstein
> Subject: Re: [ISOGEOCHEM] Physical/violent solution to
> Edwards Active Pressure Gauge problem
>
>
> Dear Wolfram,
>
> I just tried what you suggested, and it worked!  Finnigan has
> agreed to replace our gauge, so hopefully this will be only a
> temporary fix, but this is a much simpler solution than
> venting the whole system and taking the gauge apart.  Thank
> you so much.
>
> Suni
>
> On Fri, 18 Jun 2004, Dr W Meier-Augenstein wrote:
>
> > Date: Fri, 18 Jun 2004 18:37:13 +0100
> > From: Dr W Meier-Augenstein <[log in to unmask]>
> > To: [log in to unmask]
> > Subject: [ISOGEOCHEM] Physical/violent solution to Edwards Active
> >     Pressure Gauge problem
> >
> > Dear Suni,
> >
> > Another potential solution to this particular problem is to
> remove the
> > red "cap" of the gauge (grip the grey plastic and turn clock-wise
> > about 1/8 to 1/4 turn) and pull the gauge head towards you.
> >
> > Here comes the science bit. Tap (actually more of a
> controlled whack)
> > the gauge at the flange with a blunt instrument, a 32"
> spanner will do
> > nicely. This ought to loosen any dirt within the ion source part of
> > the gauge and, hey presto (after reassembling the gauge head) your
> > system should give you a "normal" read back.
> >
> > There is no guarantee this will yield the desired result but it's
> > surprising how often it does. It certainly beats shutting
> your system
> > down and venting it to air when it could have been avoided.
> >
> > Lastly, if you have to replace the active gauge make sure
> you have a
> > Al knife edge seal to go with your new gauge.
> >
> >
> > Cheers,
> >
> > Wolfram
> >
> >
> >
> > > -----Original Message-----
> > > From: Stable Isotope Geochemistry
> [mailto:[log in to unmask]]
> > > On Behalf Of Sunita R Shah
> > > Sent: 17 June 2004 18:36
> > > To: [log in to unmask]
> > > Subject: Re: Edwards Active Pressure Gauge problems
> > >
> > >
> > > Thank you for your quick reply.  I was hoping for an
> easier fix, but
> > > what you wrote makes a lot of sense.  Thanks also for taking the
> > > time to explain it to me.
> > >
> > > Suni
> > >
> > > On Thu, 17 Jun 2004, Howard Sanford wrote:
> > >
> > > > Date: Thu, 17 Jun 2004 12:56:01 -0400
> > > > From: Howard Sanford <[log in to unmask]>
> > > > Reply-To: Stable Isotope Geochemistry <[log in to unmask]>
> > > > To: [log in to unmask]
> > > > Subject: Re: [ISOGEOCHEM] Edwards Active Pressure Gauge problems
> > > >
> > > > Suni Shah wrote:
> > > >
> > > > >   The only way we can get the gauge to give
> > > > > real readings in Isodat is to remove the pressure
> gauge, take it
> > > > > apart, scrub all of the parts and start over.  Has anyone
> > > else come
> > > > > across this behavior?
> > > > >
> > > >
> > > > Yes, this is normal for this type of gauge. It itself
> is a type of
> > > > ionization source, and like any ionization source, it gets
> > > dirty and
> > > > has to be cleaned to work properly. I've had them in LC/MS
> > > > systems, MALDI-TOFs, and now in the Delta and from time to time
> > > > you
> > > just have
> > > > to take it apart and clean it. Though nine months is a little
> > > > quick for a Delta. I'd expect that on a LC/MS that gets
> a lot of
> > > > use. But then I've found some of these gauges to be more rugged
> > > > than others, even if it is the exact same model of
> gauge. Even the
> > > > same
> > > gauge can
> > > > sometimes need to be cleaned once every 3 months and
> then with no
> > > > change in instrument usage last for 3 years without
> being cleaned.
> > > >
> > > > If it becomes a big hassle you can always just buy another
> > > set of the
> > > > 'guts' from Edwards (I think its <$500US but don't quote
> > > me) and then
> > > > just swap it out when it gets dirty and clean the other at your
> > > > leisure.
> > > >
> > > >
> > > > --
> > > > Howard Sanford
> > > > 919-513-3039
> > > > North Carolina State University
> > > > Dept. of Soil Science
> > > > Box 7619
> > > > 3114 Williams Hall
> > > > Raleigh, NC 27695
> > > > http://www.soil.ncsu.edu/services/sims/
> > > >
> > >
> >
>