Recent Posts

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1
Probe for EPMA / Re: New Features In Probe for EPMA
« Last post by John Donovan on August 21, 2019, 07:26:48 pm »
During the 2019 M&M meeting Anette von der Handt gave us a few suggestions that we thought would be useful to implement. They are now available with the current version (update from the Help menu), and include first, a new "string selection" feature in the Analyze! and Automate!  windows. With this feature you can type in a string and the program will auto select all samples that contain the string. For example in the Analyze! window screenshot here, the user has typed "MB2":



We also re-arranged the controls a bit and second, brought out the "Display Samples with Data" checkbox and added another one of these checkboxes in the Plot! window, so one only sees samples that contain data, or at least contains "enabled" (not disabled) data.:



Here's a view of the new Automate! window with some re-arranged controls and the new "string selection" feature:



Maybe the layout in these windows are a bit more pleasing to the eye?
2
Cameca / Re: PHA issues
« Last post by dawncruth on August 21, 2019, 11:19:12 am »
Thanks!
3
Cameca / Re: PHA issues
« Last post by Probeman on August 21, 2019, 11:06:31 am »
Dave Adams mentions the bubbler fluid here (the trick is getting the right keywords!):

https://probesoftware.com/smf/index.php?topic=1109.msg7380#msg7380

john
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Cameca / Re: PHA issues
« Last post by dawncruth on August 21, 2019, 09:46:25 am »
John -
You mention oil filled bubblers for your Camecas. My service tech installed a bubbler for the P-10 and just recommended "mineral spirits" or isopropyl alcohol as the fluid. The alcohol evaporates pretty quickly so I'm looking for an alternative solution. Which oil is in your bubbler?

Dawn
5
Probe for EPMA / Re: Wish List for PFE Features
« Last post by John Donovan on August 20, 2019, 03:13:14 pm »
Hi John,

Any chance you could remove the popup window 'bad negative zz' and just log the error message. The problem is it opens the window consecutively many times.

When processing the data, do you do anything different with bad negative zz values. Once I've clicked the message box 20-30x the data often seems ok.


Thanks

Ben

Hi Ben,
I modified the matrix correction error messages to just log the error to the log window when it encounters negative values for certain mathematical operations.  You can update to Probe for EPMA v. 12.7.1 whenever you are ready.

Let me know if this works better for you.
john
6
CalcImage / Re: Cyclic patterns in quant data
« Last post by Probeman on August 19, 2019, 10:04:12 pm »
40 millisec is a pretty short time for that beam current (I assume you meant 40 nano-amps!). It could be simply due to counting statistics, once the background is subtracted.

One will see the same effect on an EDS spectrum when zoomed in (see attached).

Take a look at the net intensity maps and let us know what you see.
john
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CalcImage / Re: Cyclic patterns in quant data
« Last post by Ken Orr on August 19, 2019, 09:46:41 pm »
The dwell time was 40 ms with 15 kv and 40 amps. And a 2 ┬Ám pixel size. They were 16 hour maps. I don't have net intensity maps as yet. Does 40 ms sound like that might be the issue?
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CalcImage / Re: Cyclic patterns in quant data
« Last post by Probeman on August 19, 2019, 08:39:13 pm »
Hi Ken,
Just a wild guess here.

Could the raw counts per pixel be close to small integers, e.g., 1, 2, 3, etc. photons?   In other words were these pixels acquired with a very short dwell time per pixel, so only a few photons were captured?  Take a look at the net intensity maps, and look at the count rate...

By the way, what was the pixel dwell time and beam current?
john
9
CalcImage / Cyclic patterns in quant data
« Last post by Ken Orr on August 19, 2019, 08:25:57 pm »
Hi,

I'm using the polygon extraction tool to extract the quant data from my maps. When I look into the data and start plotting elements up, a cyclic pattern emerges (see attachments). I'm plotting around 40000 points from a single pyroxene grain.
This pattern occurs in all the elements. Does anyone have any ideas as to why this is happening?

Thanks.
10
OK, now on to Probe for EPMA.   We think the implementation of the ferrous/ferric calculation (from Droop, 1987) is pretty good, but please download the latest version (12.7.1) and let us know what you think.  The CalcZAF implementation is described here:

https://probesoftware.com/smf/index.php?topic=691.msg8592#msg8592

So let's take an example of hematite. Calculating all iron as FeO we get these results:

Un    3 Hematite, Results in Elemental Weight Percents

ELEM:       Fe       O
TYPE:     ANAL    CALC
BGDS:      LIN
TIME:    10.00     ---
BEAM:    30.00     ---

ELEM:       Fe       O   SUM
    29  68.992  19.766  88.758
    30  69.126  19.805  88.931
    31  68.758  19.699  88.457

AVER:   68.959  19.757  88.715
SDEV:     .186    .053    .240
SERR:     .108    .031
%RSD:      .27     .27
STDS:       39     ---

STKF:    .6810     ---
STCT:   228.06     ---

UNKF:    .6566     ---
UNCT:   219.89     ---
UNBG:      .48     ---

ZCOR:   1.0503     ---
KRAW:    .9642     ---
PKBG:   456.58     ---

Un    3 Hematite, Results in Oxide Weight Percents

ELEM:      FeO       O   SUM
    29  88.758    .000  88.758
    30  88.931    .000  88.931
    31  88.457    .000  88.457

AVER:   88.715    .000  88.715
SDEV:     .240    .000    .240
SERR:     .138    .000
%RSD:      .27  -91.65
STDS:       39     ---

Note the low totals (~88%) due to the missing ferric oxygen.  Now we specify the ferrous/ferric calculation and the mineral cations and oxygen (2 and 3 respectively for hematites) as seen here:



and re-calculating we now obtain these results:

Un    3 Hematite, Results in Elemental Weight Percents
 
ELEM:       Fe       O
TYPE:     ANAL    CALC
BGDS:      LIN
TIME:    10.00     ---
BEAM:    30.00     ---

ELEM:       Fe       O   SUM
    29  70.168  30.155 100.323
    30  70.305  30.213 100.518
    31  69.930  30.052  99.982

AVER:   70.134  30.140 100.274
SDEV:     .190    .081    .271
SERR:     .109    .047
%RSD:      .27     .27
STDS:       39     ---

STKF:    .6810     ---
STCT:   228.06     ---

UNKF:    .6566     ---
UNCT:   219.89     ---
UNBG:      .48     ---

ZCOR:   1.0682     ---
KRAW:    .9642     ---
PKBG:   456.58     ---

Ferrous/Ferric Calculation Results:
        Ferric/TotalFe   FeO        Fe2O3    Oxygen from Fe2O3
    29       1.000        .000     100.323      10.052
    30       1.000        .000     100.518      10.071
    31       1.000        .000      99.982      10.017

AVER:        1.000        .000     100.274      10.047

Un    3 Hematite, Results in Oxide Weight Percents

ELEM:      FeO       O   SUM
    29  90.271  10.052 100.323
    30  90.447  10.071 100.518
    31  89.965  10.017  99.982

AVER:   90.228  10.047 100.274
SDEV:     .244    .027    .271
SERR:     .141    .016
%RSD:      .27     .27
STDS:       39     ---

Our totals are now much better but because we included this excess oxygen in the matrix correction as suggested by Brian Joy, even more impressive is that our Fe went from 68.959 to 70.134 wt%!

We also added this ferrous/ferric output to the User Specified Output options as seen here:



so now these results can be output to Excel as usual:

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