AN ANALYTICAL XRAY SERVICES LABORATORY
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Posted by: In: Uncategorized 12 May 2016 0 comments

The last post in this series showed what can happen to the optics path of an XRD system in the wrong environment after several years of neglect. The end result of this kind of build-up is attenuation of the beam. The user will see this as a loss of intensity, but little else. In the XRF world, things are a little different because everything in the beam path can be expected to fluoresce as well as attenuate the beam. Depending upon the position and type of material, this can cause a range of interesting effects.

In the most basic case, the beam is simply attenuated as it would be in the XRD causing a loss of intensity. This would be the case with certain types of blockages in the incident beam. Several years ago I got a call from a senior tech at Bruker who was trying to help a client remotely. They’d been running fine until their intensities abruptly dropped nearly in half across the board. Checking the electronics and searching for evidence of a broken sample yielded no answers. Running previously analyzed samples proved that this was definitely not sample related. Owing to the urgency of their situation, I flew out right away with a solid kit of spare parts only to find a Post-It note sitting right on the port of the tube. Just in case there was any doubt, it had the identifier of the first sample which exhibited the symptoms written on it. It must have gotten stuck to the bottom of the cup before being loaded into the autosampler and carried all the way into the measurement position. We had a good laugh (and still do).

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Other attenuation issues aren’t so obvious. A client running heavy greases in a He environment saw a 90% drop in light element intensity while heavy elements performed fine. After some remote trouble-shooting we were able to eliminate several possibilities, but fell short of a real solution. As it turns out, the issue was caused by a crack in one of the He flush lines. These instruments don’t simply flood the chamber with He during this cycle. Rather, they start by opening two He valves (one high flow and one low flow) while turning on the vacuum pumps. Once the lines are purged, the valves close and a vacuum is pulled on the chamber. At this point, the pumps shut off and the chamber is vented to He. The split hose was leaking a very small quantity of air into the chamber at the same time it was venting to He. Even this very small amount of air was enough to devastate light element intensities.

20150107_153115-LowThe pictured issue is another very common problem. Dust from powdered samples or worse, spills or drips from liquid samples can build up on the port of the tube. The result of contamination like this is usually minimal attenuation, but it can result in a very noticeable change in the reported intensities for a given element. Most users would catch this when running a monitor standard and many would simply run a drift correction to compensate, but the best course of action is to get your service provider involved right away. They’ll be able to assess the situation quickly and might offer a better solution than simply patching the issue with a data massaging correction. At least they’ll be in the loop if the symptoms become more serious.

There are some options for keeping your port safe from this kind of contamination. We like superfluous films which keep bits of material from falling onto the tube. Mylar, Kapton (Polyimide) and Prolene (Polyprolylene) are popular choices depending upon your application. Bruker systems starting with the S4 offer a filter position with a Be shield which protects the tube window itself and works well. More exotic options (inverted optics) promise to eliminate this problem, but this offers its own challenges. For instance, the users most concerned about this kind of contamination are running liquids. Pulling a vacuum on a liquid cup makes a mess no matter where your optics are and running a liquid in an inverted cup is an added complication and opportunity for error that we’d prefer to avoid.

Posted by: In: Uncategorized 26 Apr 2016 0 comments

Most of you already know that CNC machining has been a hobby of mine for several years now. Few things are more mesmerizing to me than watching shards of metal fly off a block until the part I designed emerges at the end. I got a new project last week that I thought would be fun to share and in case you’re curious, I actually run the mill in my home garage so I can work into the evening without sacrificing too much time with my wife and kids.

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The first and second generation D8 XRD systems came with a very large octagonal housing. These are very useful when you need lots of space for extended optics, accessories or anything else you might need to store. They are particularly hard to ship though. The factory method calls for lots of bracing and crating to keep the large glass panels safe, but when one of these is shipped to us, it rarely gets this treatment. As long as the handlers are careful, this isn’t a problem, but we’ve still seen many of them with the handles broken off the bottom of the doors. Replacements are available directly from Bruker, but I’m not one to pass up a chance to run the milling machine and 3D printer.

These new Al handles are beautiful and were a great project for me to get familiar with the new mill. I’ve made several extra sets just in case the need arises in the future too.

Posted by: In: Uncategorized 30 Mar 2016 0 comments

I’m continually amazed at just how many XRD users we encounter who are only vaguely aware of what their machines can do. These instruments are relatively simple in mechanical terms, but the data they generate can unlock an amazing array of information about the sample. We’ve traveled all over the country over the last 40 years and spoken with countless XRD and XRF users. Many of these are novice users who understand the basics of their application, but little more. Some were relying on courses they’d taken in college many years before. Many had attended one class or another, but rarely felt they came away prepared for the work they’d be doing. I’ve heard so many people describe the information going “straight over my head” that I’m convinced there’s a better way to train users on the broad scope of analyses their diffractometer can perform.

We began offering training classes as soon as we started Texray hoping to fill the gap between tedious trial-and-error and, for some, ineffective large format courses. Along the way we’ve expanded our class offerings to include everything from basic theory (even general chemistry) to advanced analytical techniques such as Rietveld refinement among others. Texray is also certified by MDI to offer field training classes on all their analytical software. This allows us to arrange for demo licenses of some very powerful software for all attendees for the duration of the class.

Flexible:

Many of the clients we’ve worked with have small gaps in their knowledge which leaves them lost on the first day of a large format class. In our small groups, the curriculum is determined by the current knowledge level of the attendees and their own goals. No time needs to be spent on applications which they’ll never use and no one gets “left in the dust” on day one. Multi-stage classes begin with basic theory and progress to advanced techniques to allow for new users to get their feet wet and experienced users to broaden their skills all in a single session. Attendees may jump in and out according to their skill level.

Economical:

When a company is asked to send an employee for outside training, it usually requires a full week of their time during which they’re not covering their usual responsibilities. Travel costs and down time usually mean that a given lab will only send one or two primary users to the training class. With an on-site course from Texray, attendance is unlimited. Training two or more users represents a huge cost savings. There’s no faster or more economical way to bring your whole team up to speed.

Effective:

A highly skilled instructor comes to your site. You’ll work with your own hardware and software to eliminate the learning curve which can become an significant obstacle after large group courses. You’ll receive training targeted specifically to your applications and at a pace dictated by the attendees, not a fixed curriculum. All attendees will be provided with temporary licenses for Jade 2010 software for hands-on work throughout the class.

Posted by: In: Uncategorized 24 Mar 2016 0 comments

I’ve been wanting to write this post for a long time. I think about it every time we get a call or email from someone who wants to talk about an application that’s a little “outside the box” or just making contact to learn more about what we do. The conversation always follows a similar pattern through which they explain what’s needed and I get to offer advice based on my experience, or lack there of, with that type of work. Every time I think I’ve heard it all, I’ll get a call for something completely new. It’s a fascinating world we live in and a great time to be a scientist. That brings me to my point, these callers always seem surprised that when they call, the phone is answered by someone who is technically knowledgeable, at least familiar with the science and quite happy to talk at length about their needs. I tell them all the same thing, “This isn’t just a job, we live for this stuff.”

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CNC machining is a relatively small part of what we do at KSA and Texray, but it’s a personal hobby I enjoy quite a bit. I’ve cut many of these SS branding iron heads friends and charity auctions. They’re fun, not too complicated and really cool.

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Posted by: In: Uncategorized 24 Mar 2016 0 comments

Preventative maintenance has always been a difficult subject for me. The manufacturers all recommend an annual visit to go over their instruments in the hopes that small issues would be dealt with before they became large issues, but it’s never easy to tell a client that their perfectly functional system requires thousands of dollars in maintenance. That being said, over the last 40 years, we’ve performed countless PM routines all over the world on at least 13 different models of XRD and XRF instrumentation and almost every one of those visits has turned up at least one issue which needed attention for one reason or another. This will be the first of several posts detailing various problems we’ve encountered during these visits.

A long time client at one of our most prestigious national laboratories had gone several years without any maintenance being performed on their Siemens D500. Over that time, corrosion built up in this small receiving area before the incident beam optics. I should be very clear that this has no effect on the shutter assembly, fail-safe features or safety in general. However, if left unchecked, flakes will eventually fall into the beam path. The symptom is simply that intensities are lower. This is not the first time we’ve been called out to replace a tube only to find that the low intensities were due to attenuation. Running through a basic PM before installing the new tube saved $6000 of your tax dollars.

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Posted by: In: Uncategorized 07 Sep 2015 0 comments Tags: , , , ,

Every once in a while we get a call for components destined for custom equipment. NIST has built some extremely precise XRD instrumentation from various base components. These are operated in highly controlled environments to qualify certified reference materials (CRM). Some of our other clients have built much more proprietary, but no less impressive systems which I’d love to show in detail if the designs weren’t closely guarded intellectual property.

One of the most interesting and exciting projects we’ve seen recently is the hard-xray monochromator system developed by Dr. Gerald Seidler of University of Washington and his colleagues. The instrument itself has myriad applications, but the general idea is that many experiments which currently require synchrotron time can be performed in a laboratory setting. We’ve worked on other projects like this which were meant more qualification systems to avoid wasting synchrotron time if the experiment didn’t actually require it, but Dr. Seidlers instrument is geared toward bringing XAFS, XES and XANES right into the lab setting.  Read the full paper here.Capture

Posted by: In: Uncategorized 03 Sep 2015 0 comments

There are several key meetings and conferences each year which might concern material scientists in general, but there’s only one exclusively dedicated to analytical X-ray techniques. The Denver X-ray Conference (DXC) has been organized by the International Center for Diffraction Data (ICDD) for the past 64 years! I don’t get to attend as often as I’d like, but I’ve never regretted making the trip. It’s not always in Denver, but The Westin Hotel in Westminster, CO played host yet again this year which makes everything very convenient and relatively inexpensive. I was fortunate enough to merit an invitation from our good friends at Materials Data, Inc. this year and attended as their guest.

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The main draw for me is the educational sessions. Classes taught by legends in the industry on everything from basic XRF and XRD theory to advanced structure determination and pair distribution function (PDF) analysis. Topics vary year to year, but this time I sat in on mainly XRD courses. Instructors are usually prominent university professors or industry experts. ICDD has a strict policy against overt advertising in these sessions which means information is presented in “platform neutral” terms and is beneficial for all attendees. The exhibit hall is full of vendors promoting everything from complete XRF and XRD systems (PANalytical, Bruker, Rigaku, Thermo etc) to sample preparation equipment (Chemplex, Spex, Claisse, Mikron, Angstrom). One of the most interesting products I saw was the latest D2 Phaser from Bruker with a new LynxEye PSD capable of eliminating Cu KB1 peaks without the need for a Ni filter. This doesn’t sound like that impressive of a feat until one considers that this will triple the intensities with an inverse effect on data collection times.

Proto has expanded their offerings to include a benchtop XRD with some impressive capabilities. Most notably, it is the only benchtop I’m aware of which offers independent control of the Theta and 2Theta axes. Grazing incidence and rocking curves are valuable data collection techniques which have thus far been unavailable to small XRD users. It’s always going to be hard for a small instrument to match the data quality of a true, research grade XRD such as the D500, D5000 and D8 lines, but they’ve certainly upped their game in this area.

 

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Oxford was onhand to show off some of their very impressive low temperature stages. The more elaborate offerings are capable of cooling a sample to 12K… You read that correctly, 12 Kelvin. They do this with a regenerative He-based cooling system. I installed a D8 last year at Johns Hopkins which was purchased as nothing more than a base for one of these stages.

 

 

 

I spend most of my time bouncing between industrial, academic and government laboratories maintaining and upgrading their hardware so I see many of the attendees throughout the year though it’s rare to spend time with them casually. It’s always a good time with laughs, enlightenment and education.

 

Posted by: In: Uncategorized 03 Jul 2015 0 comments

We’ve been using additive fabrication (3D printing) and traditional subtractive methods (CNC machining) for years so when we started looking for a fun item to give away at the AAPG conference, we decided that a special Texray/KSA billet Aluminum microsplitter would be a great way to show our prospective clients that we’re not just in the business of chemical analysis, we’re passionate about it.

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It is often quipped that sampling technique is the first and most important step toward accurate results. It’s easy to get carried away focusing on instrumental repeatability and analytical error, but these can only ensure accurate results for the aliquot measured. Some of our clients are only producing materials in mg batches, but we got to talk to the users on the other end of the spectrum at AAPG last month. These geologists are concerned with the chemistry of huge formations so getting a representative analysis is critical. They’ll take thousands of samples and combine the results into extremely complicated data sets. Many of the companies exhibiting there were selling data and data representation tools and nothing else. One company specialized in moving massive quantities of data over existing internet infrastructure. Apparently many of these outfits are generating so much data that the only way to move it rapidly enough is to ship boxes of hard disk drives from the exploration site to the central lab.

Those are extreme cases and require exotic solutions. The more common situation is that a client will ship 1kg of material for us to analyze. Sampling at this scale is still an important part of getting accurate results so while it would be very easy to simply spoon a measurable aliquot from the bag, we prefer a more precise and elegant solution. Microsplitters (also referred to as “rifflers”) are a great way for labs to reduce larger bulk materials with reasonable certainty that the they’ll retain a representative sample. These indispensable little devices consist of a top section (the funnel), a splitting mechanism (I call it the comb), and two or three receptacles (bins). The comb is not simply a series of straight slits, each one has a ramped bottom which alternates between one bin or the other. In this way, the sample is divided between the two bins more or less evenly. The contents of one bin are discarded and the contents of the other bin are dumped into the funnel to be split again until the desired volume is reached. This is why it’s best to have three bins on hand.

The gallery below includes a few pictures from the initial rapid prototyping through the finished product. In the end, I added some fancy legs to the side to make it easier to use. Note that the slits are cut with a slitting saw on out CNC milling machine. This allowed for slots which have rounded edges at the top and bottom. This is critical to avoid clumping and makes a very smooth transition at the top and bottom of the comb. We may offer these as a regular product if there is enough interest to justify a production run. If that happens, customized engraving would be an option. Contact us if you’re interested.

 

Posted by: In: Uncategorized 15 Jun 2015 0 comments

AAPG2015

We had a great time at AAPG 2015. Many of our existing customers were there including some from overseas. The oil industry is in a bit of a slump, but it didn’t stop the big players (Baker Hughes, Weatherford Labs, Core Labs, Saudi Aramco, etc) from putting together very impressive booths and lots of extra activities.

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We will be exhibiting at this year’s American Association of Petroleum Geologists Annual Conference and Exhibition (AAPG ACE 2015) in Denver, CO from May 31-June 3.

Stop by our Booth #2152, speak to our team of experts, and check out video demos of what is happening at Texray. We will be handing out gifts and hosting a contest for some great prizes.

We look forward to seeing you there. If you are interested in attending but have not registered, Contact Us on how you can get a FREE Exhibit Registration.