Here's an example from a week ago where we analyzed PbSiO3 (natural Alamosite assumed stoichiometry) using SiO2 as the primary standard. Here are the results for all 11 matrix corrections:

Summary of All Calculated (averaged) Matrix Corrections:
St  386 Set   8 Alamosite (PbSiO3)
FFAST    Chantler (NIST v 2.1, 2005)

Elemental Weight Percents:
ELEM:       Si      Mg      Mn      Fe      Pb       O   TOTAL
     1  10.370   -.013   -.005    .011  73.151  16.939 100.454   Armstrong/Brown/Scott-Love (prZ)
     2   9.228   -.010   -.005    .011  73.151  16.939  99.314   Philibert/Duncumb-Reed
     3   9.691   -.011   -.005    .012  73.151  16.939  99.777   Heinrich/Duncumb-Reed
     4   9.302   -.011   -.005    .011  73.151  16.939  99.388   Love-Scott I
     5   9.423   -.011   -.005    .011  73.151  16.939  99.509   Love-Scott II
     6   8.037   -.010   -.004    .010  73.151  16.939  98.123   Packwood Phi(prZ) (EPQ-91)
     7  10.056   -.012   -.005    .012  73.151  16.939 100.141   Bastin (original) (prZ)
     8   9.481   -.011   -.005    .011  73.151  16.939  99.566   Bastin PROZA Phi (prZ) (EPQ-91)
     9   9.314   -.011   -.005    .011  73.151  16.939  99.399   Pouchou and Pichoir-Full (PAP)
    10   9.146   -.011   -.005    .011  73.151  16.939  99.232   Pouchou and Pichoir-Simplified (XPP)
    11   9.996   -.012   -.005    .011  73.151  16.939 100.080   Armstrong/Donovan and Moy BSC/BKS (prZ)

AVER:    9.459   -.011   -.005    .011  73.151  16.939  99.544
SDEV:     .612    .001    .000    .000    .000    .000    .612
SERR:     .185    .000    .000    .000    .000    .000

MIN:     8.037   -.013   -.005    .010  73.151  16.939  98.123
MAX:    10.370   -.010   -.004    .012  73.151  16.939 100.454

Percent Variances:
ELEM:       Si      Mg      Mn      Fe      Pb       O
PUBL:    9.910    n.a.    n.a.    n.a.  73.151  16.939
STDS:       14      12      25     395     ---     ---

ELEM:       Si      Mg      Mn      Fe      Pb       O
     1    4.65     ---     ---     ---     ---     ---           Armstrong/Brown/Scott-Love (prZ)
     2   -6.88     ---     ---     ---     ---     ---           Philibert/Duncumb-Reed
     3   -2.21     ---     ---     ---     ---     ---           Heinrich/Duncumb-Reed
     4   -6.13     ---     ---     ---     ---     ---           Love-Scott I
     5   -4.91     ---     ---     ---     ---     ---           Love-Scott II
     6  -18.90     ---     ---     ---     ---     ---           Packwood Phi(prZ) (EPQ-91)
     7    1.47     ---     ---     ---     ---     ---           Bastin (original) (prZ)
     8   -4.33     ---     ---     ---     ---     ---           Bastin PROZA Phi (prZ) (EPQ-91)
     9   -6.01     ---     ---     ---     ---     ---           Pouchou and Pichoir-Full (PAP)
    10   -7.71     ---     ---     ---     ---     ---           Pouchou and Pichoir-Simplified (XPP)
    11     .87     ---     ---     ---     ---     ---           Armstrong/Donovan and Moy BSC/BKS (prZ)

AVER:    -4.55     .00     .00     .00     .00     .00        
SDEV:     6.18     .00     .00     .00     .00     .00        
SERR:     1.86     .00     .00     .00     .00     .00        

MIN:    -18.90     .00     .00     .00     .00     .00        
MAX:      4.65     .00     .00     .00     .00     .00        

That's pretty wild, right?

Note the magnitude of the atomic number correction (from DebugMode in PFE or CalcZAF), for the last data point:

SAMPLE: 2545, ITERATIONS: 3, Z-BAR: 48.30882

 ELEMENT  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR STP-POW BKS-COR   F(x)u      Ec   Eo/Ec    MACs  STDNUM uZAF/sZAF
   Si ka  1.6104   .9949   .7741  1.2402   .6403  1.2089   .5346  1.8390 10.8755 1355.02      14    1.0382
   Mg ka  2.4771  1.0000   .7735  1.9161   .6260  1.2358   .3264  1.3050 15.3257 2742.98      12    1.3592
   Mn ka  1.1342  1.0000   .8759   .9935   .8040  1.0894   .8562  6.5390  3.0586 356.758      25    .95158
   Fe ka  1.1032   .9854   .8580   .9327   .7936  1.0811   .8833  7.1120  2.8121 289.657     395    .88853

 ELEMENT   K-RAW K-RATIO ELEMWT% OXIDWT% ATOMIC% FORMULA TAKEOFF KILOVOL                                        
   Si ka  .20530  .08033   9.962   -----  20.085    .000   40.00   20.00                                        
   Mg ka -.00019 -.00008   -.016   -----   -.037    .000   40.00   20.00                                        
   Mn ka -.00008 -.00006   -.006   -----   -.006    .000   40.00   20.00                                        
   Fe ka  .00024  .00016    .015   -----    .015    .000   40.00   20.00                                        
   Pb                     73.151   -----  19.993    .000
   O                      16.939   -----  59.950    .000
   TOTAL:                100.045   ----- 100.000    .000

And here for those interested are the analysis for all data points using the Armstrong/Donovan and Moy matrix correction:

St  386 Set   8 Alamosite (PbSiO3)
TakeOff = 40.0  KiloVolt = 20.0  Beam Current = 30.0  Beam Size =   10
(Magnification (analytical) =  20000),        Beam Mode = Analog  Spot
(Magnification (default) =     1000, Magnification (imaging) =    100)
Image Shift (X,Y):                                         .00,    .00

Tsumeb, South West Africa
From Mineralogical Research, CA
(assumed stoichiometric)
Number of Data Lines:   6             Number of 'Good' Data Lines:   6
First/Last Date-Time: 04/19/2026 10:56:41 PM to 04/19/2026 11:08:42 PM

Average Total Oxygen:         .000     Average Total Weight%:  100.080
Average Calculated Oxygen:    .000     Z-Bar (Z Fraction^0.7):  48.289
Average Excess Oxygen:        .000     Average Atomic Weight:   56.630
Average ZAF Iteration:        3.00     Average Quant Iterate:     2.00

St  386 Set   8 Alamosite (PbSiO3), Results in Elemental Weight Percents
 
ELEM:       Si      Mg      Mn      Fe      Pb       O
TYPE:     ANAL    ANAL    ANAL    ANAL    SPEC    SPEC
BGDS:      LIN     LIN     LIN     LIN
TIME:    60.00   60.00   60.00   60.00     ---     ---
BEAM:    29.88   29.88   29.88   29.88     ---     ---

ELEM:       Si      Mg      Mn      Fe      Pb       O   SUM  
  2540  10.013   -.014   -.001    .008  73.151  16.939 100.096
  2541  10.000   -.007   -.011    .011  73.151  16.939 100.083
  2542  10.020   -.009   -.001    .009  73.151  16.939 100.109
  2543  10.001   -.020   -.005    .009  73.151  16.939 100.074
  2544   9.982   -.009   -.003    .014  73.151  16.939 100.074
  2545   9.962   -.016   -.006    .015  73.151  16.939 100.045

AVER:    9.996   -.012   -.005    .011  73.151  16.939 100.080
SDEV:     .021    .005    .004    .003    .000    .000    .022
SERR:     .009    .002    .001    .001    .000    .000
%RSD:      .21  -38.89  -76.31   27.89     .00     .00

PUBL:    9.910    n.a.    n.a.    n.a.  73.151  16.939 100.000
%VAR:      .87     ---     ---     ---     ---     ---
DIFF:     .086     ---     ---     ---     ---     ---
STDS:       14      12      25     395     ---     ---

STKF:    .3913   .4276   .7418   .6867     ---     ---
STCT:  2304.52  745.26  466.57 1036.19     ---     ---

UNKF:    .0806  -.0001   .0000   .0001     ---     ---
UNCT:   474.75    -.11    -.03     .18     ---     ---
UNBG:    11.48    1.53    1.62    5.04     ---     ---

ZCOR:   1.2402  1.9158   .9936   .9328     ---     ---
KRAW:    .2060  -.0002  -.0001   .0002     ---     ---
PKBG:    42.37     .93     .98    1.04     ---     ---

Quote from: Ben Buse on April 27, 2026, 07:10:03 AMAlso need to figure out how to load files into calcimage best.

At moment I'm creating a new blank project in calcimage and then loading each of the files as grd files. Is there a better way of doing this.

I can work with you on this, but for now can you use MAN WDS maps as Jon suggests?

Quote from: Ben Buse on April 27, 2026, 07:10:03 AMI tried loading the wds elements through the create project wizzard. But when I added eds grd files at the end, it said must be added before off peak maps.

Yes, that is because the Wizard is looking for PrbImg files to convert to GRD files.  You could possibly create/modify the CalcImage .CIP file to contain all the WDS and EDS GRD files in the proper order.

You've seen this button?

https://smf.probesoftware.com/index.php?topic=1544.msg11942#msg11942

The idea was to query the EDS vendor software to extract net intensity/live time maps for each EDS element. We almost got it all working in Thermo as we needed Thermo to add an API function to obtain the EDS live times per pixel because one needed to extract those manually using the PathFinder application.  Then Thermo bought FEI and dropped all development for EPMA EDS systems...

If you contact me off-line I can share the read/write code for the CalcImage .CIP format with you.

Quote from: Ben Buse on April 27, 2026, 07:10:03 AMOk here's the eds & wds combined.

Although need to check the quant...

Also need to figure out how to load files into calcimage best.

At moment I'm creating a new blank project in calcimage and then loading each of the files as grd files. Is there a better way of doing this.

I tried loading the wds elements through the create project wizzard. But when I added eds grd files at the end, it said must be added before off peak maps.

The totals look quite high at the minute. How are you background correcting the EDS intensities?

For CalcImage, are you doing WDS background maps or MAN backgrounds? I usually use MAN background intensities for WDS maps and load them in using the wizard, then add EDS maps via "Add Images Files to Project (*.GRD)"

Quote from: aducharme on April 27, 2026, 12:08:51 AM

Quote from: Probeman on April 20, 2026, 11:09:55 AMDo you want to "break" the EPMA 1% accuracy barrier?  You need to make sure your PHA peaks are completely above the baseline level at the highest count rate you anticipate measuring and be in *integral* PHA mode.

Paul Carpenter, 2008: "Avoid tight PHA window, use integral mode unless a PHA interference is observed" and "Use integral mode unless PHA energy discrimination required" (https://epmalab.uoregon.edu/Workshop2/Carpenter_Oregon_Workshop_2007.pdf)

Nice find. 

Yes, Paul has been saying this all along, but there's a critical component that I'm not seeing in his presentation.

For example, he says: "Low energy pulses must be discriminated from baseline noise. Need proper setting of noise threshold, baseline, and window settings of WDS pulse height analyzer."

And that is certainly true. But it would be better to merely say: make sure that the PHA peak is completely above the baseline level at the highest count rate that one intends to measure.

Then there is no need to perform "count rate matching" as he claims a bit later on: "Pulse energy shift with varying count rate results in instability. At high count rates pulses are poorly discriminated from baseline noise. Use similar count rates on standard and sample".  I say we don't need to "count rate match" if we tune our PHAs properly...

Also, it's not "instability" that occurs with "pulse energy shift" or what I would call "pulse height depression".  What occurs when the PHA peaks starts to shift lower (at higher count rates) or shifts higher (at lower count rates), is not "instability" but rather "non-linearity".  This is exactly why people seem to think that they need to "count rate match" their standard and unknown, but it is simply not necessary as long as one sets their PHA gain or bias high enough so that the PHA peak is *completely* above the baseline level at the highest count rate that one expects to measure (usually the highest concentration (primary std) at the highest beam current to be utilized).

That is, as the PHA shifts higher or lower, the baseline either cuts off pulse counts or includes more pulse counts from the left side tail of the PHA peak, thus introducing a non-linear response as a function of count rate.

Paul then mentions this: "Avoid tight PHA window, use integral mode unless a PHA interference is observed." But I would modify this to say: Because the use of PHA differential mode does not help with same Bragg order interferences, instead allow all interferences (same or higher order) to be counted and deal with the interferences properly using the quantitative interference correction.

I say this because, even in the case of higher order interferences, one cannot be sure that the interference pulses are cleanly separated from the interfered pulses. 

It is far better to obtain a linear response from our detectors/counting electronics and deal with any interference corrections in software. The one exception I can think of is maybe analyzing trace oxygen in a Na compound because it's difficult to find a material containing a known amount of Na but no oxygen, for use as an interference standard!

Ok here's the eds & wds combined.



And input files


Although need to check the quant...

Also need to figure out how to load files into calcimage best.

At moment I'm creating a new blank project in calcimage and then loading each of the files as grd files. Is there a better way of doing this.

I tried loading the wds elements through the create project wizzard. But when I added eds grd files at the end, it said must be added before off peak maps.

you will see the secondary electrons in the simulation result trajectory display as long as the tracking SE in enabled, the blue trajectories are primary electrons, the red ones are backscattered electrons escaped out of surface, and you can see many short trajectories with green color along the primary trajectories, which are secondary electrons.

I could be wrong, but my understanding is that the SE yield only counts the SEs escaped out of the surface.

zhlltu2026

Quote from: Probeman on April 20, 2026, 11:09:55 AMNow just to "knock your socks off" here was the PHA tuning we used for Fe Ka:



Do you want to "break" the EPMA 1% accuracy barrier?  You need to make sure your PHA peaks are completely above the baseline level at the highest count rate you anticipate measuring and be in *integral* PHA mode.

Paul Carpenter, 2008: "Avoid tight PHA window, use integral mode unless a PHA interference is observed" and "Use integral mode unless PHA energy discrimination required" (https://epmalab.uoregon.edu/Workshop2/Carpenter_Oregon_Workshop_2007.pdf)

I really enjoyed this book on the history of electromagnetic fields:

https://www.amazon.com/Faraday-Maxwell-Electromagnetic-Field-Revolutionized/dp/1633886077

"The story of two brilliant nineteenth-century scientists who discovered the electromagnetic field, laying the groundwork for the amazing technological and theoretical breakthroughs of the twentieth centuryTwo of the boldest and most creative scientists of all time were Michael Faraday (1791-1867) and James Clerk Maxwell (1831-1879)."

Some of us (myself included) will lament the fact that NIST no longer seems to be interested in producing accurate microanalytical standards, but we can obtain this standard from them:



To add further insult to injury, apparently we can now also get this standard:



https://www.nist.gov/news-events/news/2025/03/nist-releases-reference-material-aid-gut-microbiome-research

So you might say, we can get shit standards from NIST, but not microanalytical standards!   

Quote from: John Donovan on May 14, 2025, 11:34:07 AMWe just wanted to remind our customers that if you have Probe for EPMA (or even just our free CalcZAF/Standard) software, you can update your software for free any time.

If you are using a relatively recent version of Probe for EPMA (or CalcZAF) you can update either one from the Help menu.  If that doesn't work, just go to our web site resources page and download then latest updates by clicking on one of the Download buttons:

https://www.probesoftware.com/resources/

Just to clarify: Probe Software never charges for software updates, they are always free!

We merely ask that when you purchase a new instrument (every 10 to 20 years!) you also buy our software (and one of our installation and training options) either from JEOL or directly from us.

And don't hesitate to contact us if you have any questions at all.