Hey Bjoern,

I'm definitely not familiar with re-aligning the cavity.  Seems like you would actually need manufacturer equipment to do that.  Definitely a changing the oil vs. transmission rebuild situation. 

As far as recommendations concerning repair vs. repurchase I think that all depends on your situation and future goals.  If you only see yourself needing to get data for a small amount of time/samples then maybe just a repair?  I'm not sure how much a new similar Picarro is but a comparable LGR model to what I have is roughly $60k so you would be paying a third of a new machine to have a much older machine hopefully keep working?  Maybe they have a trade in policy so you can get the price of a new one lowered a bit if you intend to keep running samples into the extended future.

Good luck!

Vince

On Wed, Apr 12, 2017 at 3:46 PM, mwolhowe . <[log in to unmask]> wrote:
Ah, yes actual spec problems in the cavity are well outside my purview. There are some less serious issues I've resolved myself, so I had my fingers crossed. Good luck!

Dr. Matthew Wolhowe
Postdoctoral Research Fellow
University of Washington School of Oceanography

On Wed, Apr 12, 2017 at 3:04 PM, Bjoern Wissel <[log in to unmask]> wrote:

Hello Vince,

 

Thanks for your suggestions. The actual diagnosis (see below) is a slight misalignment in the cavity as well as a minor leak. We can fix the leak part in-house (damaged thread on the intake nut, which are Swagelok components) but the cavity repair is supposed to be done at the factory.

 

Cheers, Bjoern

 

When looking at your instrument it seems that there might be a slight miss alignment in the cavity.  When running further test I was able to scan the spectra and it looks like it is mostly effecting your 18 O region.  With this a slightly miss alignment in the optical components will create a shadow or doublet of the measured spectra.  I originally thought that since your instrument was off it would disappear,  I also looked at trying to remedy the issue by increasing your threshold but you are already at the maximum.  Unfortunately this means that your instrument must come back for a cavity repair.  

If you do not wish to send back the instrument you can use it but we cannot guarantee out spec on the COC form.  I would try to run a drift test to find out what your current precision is.  If you are okay with your precision you are able to still use the instrument.  Please let me know your thoughts.

 

 

--

Björn Wissel, PhD

Associate Director, Institute of Environmental Change and Society

Adjunct Professor, Department of Biology

525 Research and Innovation Centre

University of Regina

Regina, SK S4S 0A2 Canada

phone    306 585-4890

fax      306 337-2410

e-mail   [log in to unmask]

 

www.iecs-uregina.ca

www.uregina.ca/biology/index.php?page=faculty/Wissel2

 

From: Stable Isotope Geochemistry [mailto:[log in to unmask]u] On Behalf Of Randall Debes
Sent: April-12-17 3:50 PM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] Picarro L2120i CRDS question

 

Hi Bjorn,

 

I don't have a Picarro CRDS, I'm using a LGR CRDS circa 2010 so the actual physical schematics might be different but the technology is similar.  I've been troubleshooting for instrument for years so I might be able to give some direction.  

 

What exactly are the issues?  You mentioned H2O concentration, does that mean the injection volume is changing during the run? How are the d18O values changing?  Does it seem like instrumental drift?

 

The concentration could be a matter of clogged lines, faulty syringes, or a leak in the plumbing somewhere (maybe a faulty/sticking valve).  I have replaced my sample transfer line and filter many times because the samples I am running are high in dissolved silica so it builds up in the system.  You might want to clean the injection block as well.  

 

As for the cavity replacement, unless the mirrors are broken or scratched, I don't think that is really necessary.  I have cleaned the mirrors on my instrument which helped with odd d18O drift.  Picarro probably has a procedure for this, LGR did and they even sent me a kit with everything I needed to do it myself.  

 

I've been keeping my instrument alive myself for years due to lack of "send it to LGR" money as well.  LGR and Picarro tout these instruments as "rugged, reliable, and field ready" but more and more I think that description is more meant for the first couple years after purchase.

 

Cheers!

 

Vince

 

On Wed, Apr 12, 2017 at 11:18 AM, mwolhowe . <[log in to unmask]> wrote:

Bjorn-

What's the actual diagnosis? I've had to fix some things myself due to "send it in to Picarro" money not being there, as has a colleague of mine with even more experience. So far Picarro support has been pretty helpful with leading me through the do-it-yourself options, but maybe it's something one of us has experience taking care of?

Dr. Matthew Wolhowe

Postdoctoral Research Fellow

University of Washington School of Oceanography

 

On Wed, Apr 12, 2017 at 10:05 AM, Andrew Schauer <[log in to unmask]> wrote:

Hi Björn,

 

We now budget for this sort of repair as it has happened to us once. I wonder if we should be thinking of these instruments more as modern smart phones and computers where we can't expect more than 5 years out of them. So sad. 

 

andy

 

On Wed, Apr 12, 2017 at 8:14 AM, Bjoern Wissel <[log in to unmask]> wrote:

Dear list members,

 

We have been using a Picarro L2120i water analyzer since 2012. In total we probably analyzed about 5000 samples (incl. standards), at eight injections each. Most samples are from Canadian prairie lakes which have slightly elevated salinity of up to 1 to 2 psi.

 

Recently, we ran into an issue that effects H2O concentration and del18O measurements. After diagnosis we are looking at a $20K fix/replacement of the cavity and a downtime of several months.

 

Based on the age, model and use of the instrument I am trying to gauge if a repair is warranted of if we should rather invest in a new CRDS.

I would greatly appreciate any comments, experiences, suggestions regarding this issue.

 

Thanks and all the best, Bjoern

 

 

--

Björn Wissel, PhD

Associate Director, Institute of Environmental Change and Society

Adjunct Professor, Department of Biology

525 Research and Innovation Centre

University of Regina

Regina, SK S4S 0A2 Canada

phone    306 585-4890

fax      306 337-2410

e-mail   [log in to unmask]

 

www.iecs-uregina.ca

www.uregina.ca/biology/index.php?page=faculty/Wissel2

 



 

--

 



 

--

Randall (Vince) Debes

Research/Lab Aide

Arizona State University

School of Earth and Space Exploration





--
Randall (Vince) Debes
Research/Lab Aide
Arizona State University
School of Earth and Space Exploration
Tel: 4802205918