[meteorite-list] XRF Test results UNWA First try

From: Norm Lehrman <nlehrman_at_meteoritecentral.com>
Date: Thu, 30 Jun 2011 22:19:13 -0700 (PDT)
Message-ID: <1309497553.60555.YahooMailRC_at_web81004.mail.mud.yahoo.com>

All,

I work with a hand-held Niton XRF on a regular basis, and they are amazing
machines if one recognizes their proper applications and limitations.? The first
limitation is that they can't measure anything lighter than sodium (or more
realistically, sulfur) unless you buy a super expensive helium-purged unit.? The
light elements present their own set of problems even then.? For example, a
significant part of the signal return would be from the air, not the sample,
unless you undertake the measurements in a vacuum.??? However, the inability to
measure the light elements has a few benefits.? You can measure directly through
low molecular weight substances, so plastic bags or surface coatings are no
problem.

Detection limits vary from element to element and sample to sample depending on
spectral interference from other elements present.? One must always consider
results in light of the detection limit, which is reported for every reading.?
It is common to see results like "5ppm +/- 150ppm" (in which case the 5 ppm is
utterly meaningless), so an analytical report that doesn't include the detection
limits can be entirely misleading. (The unit allows one to configure the
reporting format such that detection limits are included).? Some elements, such
as gold, can only be resolved from interfering wavelengths at high
concentrations, so the machine becomes quite useless when dealing with more
typical ppb concentrations of gold.

So, some of the elemental ratios of the lighter rock-forming elements that are
often cited in chondrite classifications are not going to be measured with a
portable XRF.? For the heavier elements like iron and nickel, it is pure magic.?
The machine can be set to automatically average multiple readings so that
inhomogeneities in the sample are averaged.? When working with flat slabs, you
can even "paint" the sample window back and forth while the reading is in
progress to get better representations of the average composition.? The units
come from the factory able to directly recognize a range of industrial metal
alloys.? You could quite certainly develop your own standards so that the
read-out could actually be "campo" or "sikhote" rather than a list of elements!

The bottom line is that, like every tool, one must understand what it can and
cannot do.? Then work with the strengths and avoid the weaknesses.

The last unit my employers purchased a few months ago was priced at $29,900 plus
another $2300 for a portable analytical chamber (in which you can get good
readings on a medium-sand-sized particle).? The operating costs are virtually
nil, but the x-ray tube does have a finite life (around 10,000 measurements),
after which the unit must be returned to the factory for a replacement tube (I
haven't had to replace one yet, but I think the cost is in the $10,000 range).?
There are licensing requirements that vary from state to state and country to
country.

Cheers,
Norm
www.tektitesource.com

?


----- Original Message ----
From: Jim Wooddell <jimwooddell at gmail.com>
To: Meteorite List <meteorite-list at meteoritecentral.com>
Sent: Fri, July 1, 2011 2:00:36 AM
Subject: Re: [meteorite-list] XRF Test results UNWA First try

Hello Count

The one we are playing with now is a Niton XL3t.? It's about $30k but
don't quote me on that.? Google Niton XRF and you'll find it.
A few people have responded and we are going to see if we can add to
the element list.
Kind Regards,
Jim Wooddell

On Thu, Jun 30, 2011 at 3:47 PM, Count Deiro <countdeiro at earthlink.net> wrote:
> Anyone on List like to smarten me up as to what one of these XRF "guns" cost
>and where one could be purchased?
>
> Count Deiro
> IMCA 3536
>
>
> -----Original Message-----
>>From: Jim Wooddell <jimwooddell at gmail.com>
>>Sent: Jun 30, 2011 2:01 PM
>>To: cdtucson at cox.net
>>Cc: Meteorite List <meteorite-list at meteoritecentral.com>
>>Subject: Re: [meteorite-list] XRF Test results UNWA First try
>>
>>Hi!
>>
>>I am not trying to compare. ?All I need is a go - no go. ?Then it's
>>off to a lab for classification.
>>
>>I had sent this lady a list for elements. ?She is going to see if she
>>can do them when she get home. ?Her gun is one of the better higher
>>end units.
>>
>>So I will add Cr Mn and Na, thank you.
>>
>>I had so far....
>>Ca
>>Cr
>>Si
>>Ni
>>Mg
>>Ga
>>Al
>>Fe
>>Mn
>>Ti
>>Na
>>
>>Thanks
>>
>>Jim
>>
>>
>>On Thu, Jun 30, 2011 at 1:14 PM, ?<cdtucson at cox.net> wrote:
>>> Jim,
>>> My posts are moderated so, they do not post in real time but , ?until Art
>>>releases them. Please excuse these delays.
>>> I don't know of any such links with XRF generated data.
>>> I only had my own data that I paid Blaine to produce from my own rocks.
>>> In order to compare data with that of known meteorites you have to have data
>>>for a few certain elements. Not the info you got from your XRF results.
>>> All of the published needed data that is used to plot these charts with are
>>>basically the same.
>>> the data you got for your UNWA is arbitrary in that nobody really uses much of
>>>what you were given for much of anything.
>>> The elements you do need data for are at a minimum is ?the following;
>>>
>>> Si, Ti, Al, Cr if possible because Cr is very telling , Fe, Mn, Mg, Ca,Na,
>Ni,
>>> With this data you can then go to published meteorite classifications and
>>>compare your numbers with theirs as reflected both in print form and on charts
>>>and graphs.
>>>
>>> This is the info that Blaine furnishes with his XRF gun services he provides.
>>>It should be useful to use to plot charts with but, this is the question that
>>>remains unanswered. What good does having this info really do if nobody
>>>acknowledges the comparisons as significant or relevant?
>>> Carl
>>> meteoritemax
>>>
>>>
>>>
>>>
>>>
>>> "Democracy is two wolves and a lamb voting on what to have for dinner. Liberty
>>>is a well-armed lamb contesting the vote".
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ---- Jim Wooddell <jimwooddell at gmail.com> wrote:
>>>> Hello Carl,
>>>>
>>>>
>>>> If you have links to XRF test result data on meteorites, can you
>>>> please provide them to me?
>>>>
>>>> Thank you
>>>>
>>>> Jim Wooddell
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Thu, Jun 30, 2011 at 10:14 AM, ?<cdtucson at cox.net> wrote:
>>>> > Jim, Scientists, List,
>>>> > I 'd like to hear more on this topic as well. Preferably from a qualified
>>>>Scientist as far as where exactly this test ends up taking us?
>>>> > I have ?personally had several of these tests done on dozens of prospect
>>>>rocks. ?. In my mind I thought I could easily use this chemical data to compare
>>>>my data with known meteorites and determine based on like chemistry what I might
>>>>have. This way no scientist is bothered by me until I had something to show
>>>>them.
>>>> > At the end of the day. ?The results have ?turned out to be less telling than
>>>>I expected.
>>>> > My madness was based on the fact that nearly all if not all rare meteorites
>>>>that are classified as a particular classification are plotted on little charts
>>>>and graphs to show that they plot with other known material of the same
>>>>classification. And states the case that since known meteorite "A" plots in all
>>>>of these areas and meteorite "B" plots right with them, then it too is the same
>>>>classification. I know O tests are also needed but that is not in question here.
>>>> > What I question is; ?that this test in and of itself evidently proves
>>>>nothing?
>>>> > In fact it seems that Scientists already know this? ?So, these tests have
>>>>proven to be a complete and utter waste of time money and energy when done by
>>>>laymen?
>>>> > This because I ended up having several rocks with the correct chemistry to
>>>>plot EXACTLY ?on the Mars and Lunar charts right with the known meteorites. (to
>>>>add to this confusion, there are also known meteorites that do not plot
>>>>perfectly on these charts ?so, they are simply left off the chart but,
>>>>acknowledged with a different color plot mark.).
>>>> > I thought this would be an easy home test. Simply go to Randy's site and copy
>>>>all of his amazing charts and plot your results directly onto the same charts he
>>>>provided. If they plot with Randy's plots then , they are from the moon. Go to a
>>>>number of other sites and print out these same charts from Mars and plot your
>>>>results right with theirs.
>>>> > This method actually worked out for Calcalong Creek. The first Lunar found
>>>>outside of Antarctica.
>>>> > Bonyton, Hill and Haag saw a meteorite that looked Lunar so, they broke down
>>>>it's chemistry and determined that since it's ratios were similar to the known
>>>>moon's ratios. (yes, there were also like minerals) ?. Therefore it is Lunar.
>>>>This determination was made prior to having Oxygen isotopic studies done on the
>>>>material. (which as we all now know is important). ?In fact the formal
>>>>presentation of this amazing little meteorite not only declares it has a Lunar
>>>>origin but, it also reemphasizes the fact that these chemical ratios are
>>>>actually definitive of origin. Therefore any meteorite that matches these ratios
>>>>must originate from the same parent body. Which ?In that case was the Earth's
>>>>moon.
>>>> > Again, I have found this is either not the case for the layman or the testing
>>>>is flawed?
>>>> > Blaine knows his testing gun pretty well by now and he feels his numbers are
>>>>pretty accurate and it seems to me they must be at least as good as the Mars
>>>>probes and other remote sensing devises are that we use and trust?
>>>> > This said because I also have rocks that plot exactly with some of the ones
>>>>the Mars probes sniffed. They too are charted and graphed so it is very easily
>>>>to plot your own results right on the same charts generated by other scientists.
>>>> > I have spent Hours working on these charts and yet no matter how close they
>>>>plot to other known material.
>>>> > If the rock did not fall from the sky and hit you on the head and leave
>>>>fusion crust embedded in your skull. Then it is not worthy of study so these XRF
>>>>tests are virtually useless???
>>>> > So, the question is ; what have ratios to do with this after all?
>>>> > It seems to me that a test that proves a rock was in space available to the
>>>>public is the only real way to determine origin unless you are a Scientist
>>>>working in the field. Home tests just don't seem to work out. Do they?
>>>> > Carl
>>>> > Meteoritemax
>>>> >
>>>> >
>>>> > --
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > "Democracy is two wolves and a lamb voting on what to have for dinner.
>>>>Liberty is a well-armed lamb contesting the vote".
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > ---- Jim Wooddell <jimwooddell at gmail.com> wrote:
>>>> >> Hi all!
>>>> >>
>>>> >> I sent a sample UNWA (for her to keep) to a person that had never
>>>> >> tested meteorites before with her Niton XL3t gun with a 50kv x-ray
>>>> >> tube. ?She normally test other types of environmental testing with her
>>>> >> gun and is very good at it.
>>>> >>
>>>> >> She return a standard report using two different methods of testing.
>>>> >> Table 1 is Test All mode and Table 2 is Metals & Minerals.
>>>> >>
>>>> >> The results are in Parts Per Million.
>>>> >>
>>>> >> I was wondering if I may ask for comments and suggestions on this
>>>> >> report? ?You can see it here:
>>>> >> http://desertsunburn.no-ip.org/57gUNWA.jpg
>>>> >>
>>>> >> Thanks
>>>> >>
>>>> >> Jim Wooddell
>>>> >> ______________________________________________
>>>> >> Visit the Archives at
>>>>http://www.meteoritecentral.com/mailing-list-archives.html
>>>> >> Meteorite-list mailing list
>>>> >> Meteorite-list at meteoritecentral.com
>>>> >> http://six.pairlist.net/mailman/listinfo/meteorite-list
>>>> >
>>>
>>______________________________________________
>>Visit the Archives at
>http://www.meteoritecentral.com/mailing-list-archives.html
>>Meteorite-list mailing list
>>Meteorite-list at meteoritecentral.com
>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>
>
______________________________________________
Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html
Meteorite-list mailing list
Meteorite-list at meteoritecentral.com
http://six.pairlist.net/mailman/listinfo/meteorite-list
Received on Fri 01 Jul 2011 01:19:13 AM PDT