How do I specify a non-pure element standard in CalcZAF?

[JohnF]

I am trying to run the "check all spectrometers for equivalent K-ratio" test on my microprobe. That is, verify
(1) that all spectrometers give equivalent K-ratios for a specific crystal  and
(2) that the values returned are the correct values.

I have acquired Mg, Si and Al Ka counts on TAP on 3 spectrometers, on both oxide standards, and on a "good" reference material (NIST K412) which I am using as the test. I see 2 spectrometers give very close counts to one another and the 3rds is somewhat different. The question is, are the 2 correct and the 1 is not? For that I want to use CalcZAF to determine the theoretical raw-K-ratio for the 3 characteristic peaks, but when I "enter composition from database" for K412 (which I have as a std in the std database), and click "calculate" it shows the theoretical k-ratio relative to pure element std. If I click on an element (e.g. Mg), Element Properties box pops up, and Assigned Standard is a box, but it is greyed out and I cannot tell it to use my MgO as the std. I'm sure there is some way to tell it to use MgO but I don't see how.  What is the solution?

Thanks for making this great software available. 

[John Donovan]

Hi John,
Simply use the Output | Save CalcZAF Format menu in PFE to export your data and re-calculate it in CalcZAF. Note that if you enter a composition in CalcZAF it calculates intensities (k-ratios) from the composition. But if you enter intensities (manually or by importing from PFE), it will calculate concentrations.

But for your k-ratio comparison, you can simply look at the k-raw when the element is assigned as the primary element and is re-calculated as a standard. 

Or convert using the std k-factor. Of course that depends on the matrix correction.

But for simply comparing that all your spectrometers give the same k-ratio within precision, all of this is really unnecessary since you just want to know if they all agree.  Who is to say what they "should be" except by measurement!

[John Donovan]

I should also add, that adding a compound standard is easy if you first select one of the intensity to concentration calculation options in CalcZAF.  Then just click on each element to modify the primary standard.

Edit: of course you'll need to add the standards to the calculation using the Standard | Add/Remove Standards To/From Run menu.

See the example CalcZAF.dat file for examples by clicking the File | Open CalcZAF Input data File menu:



Simply click the Load Next Dataset From Input File button to see each data set one at a time and click the Calculate button to see the calculation results:

[John Donovan]

If the standard composition you want to specify for quantitative analysis in CalcZAF is *not* in the standard database, then you will need to add it to the standard database (Standard.mdb) using the Standard | New menu in Standard.exe. All standard compositions in Probe Software applications are indexed by a unique integer standard number.

If you would like a good introduction to using CalcZAF, this thread provides a starting point:

http://probesoftware.com/smf/index.php?topic=81.0