Hi all,
I have been playing with the feature in PfEPMA where you can designate different coatings for standards/unknowns and was wondering if anyone knew how well or if this feature worked.
I have attached a excel file that shows the results of the PfEPMA matrix correction with and without the coating correction. In this case my carbon standard was un-coated, the rest of the standards were C coated, with the exception of the Fe and Si standards were Pt coated at the same time as the unknown. I would have thought add/removing this correction would have a larger effect on the wt %, does anyone have any insight as to why the correction is so small. I have done some of the monte carlo modeling and we should be seeing more counts on the platinum coated sample.
Cheers,
phil
Edit by JJD to add Excel sheet as attachment
The coating correction in PFE is quite a crude correction. One part is an absorption correction for low energy x-rays emitted through the coating and the second, is a correction for electron energy loss from primary electrons going through the coating.
It does not account for additional emitted x-rays from the coating.
An improved coating correction has been implemented in Probe for EPMA (and CalcZAF) based on a modified coating correction by Kerrick, et. al., Amer. Min. 58, 920-925 (1973). You'll need v. 10.3.6 to utilize these new methods.
There are two parts to this coating correction:
1. A correction for "electron absorption" which compensates for the decrease in over voltage as the beam decelerates through the coating thickness.
' Intensity correction from electron energy loss due to coating
ratio! = (100# - ((8.3 * sample(1).CoatingDensity! * sample(1).CoatingThickness! / ANGPERNM&) / (sample(1).KilovoltsArray!(chan%) ^ 2 - (sample(1).LineEdge!(chan%) / EVPERKEV#) ^ 2))) / 100#
2. A correction for x-ray attenuation as the emitted x-ray transmits through the coating layer (coating thickness / Sin (theta)).
' Calculate thickness based on takeoff angle
radians! = sample(1).takeoff! * PI! / 180#
thickness! = sample(1).CoatingThickness! / Sin(radians!)
' Calculate x-ray transmission based on Sin thickness in angstroms
transmission! = NATURALE# ^ (-1# * atotal! * sample(1).CoatingDensity! * thickness! * CMPERANGSTROM#)
A test sample was prepared of an ultra pure Ti metal coated with pure Ag. The thickness was determined by XRR as 120 nm as shown in the following diffraction fringes:
(https://smf.probesoftware.com/oldpics/i59.tinypic.com/30wbdb4.jpg)
A separate determination was performed using StrataGEM using 6, 8 and 15 keV which gave 124.7 nm assuming a density of 10.5 for Ag and no carbon coat on the pure Ti or the Ag coated Ti.
(https://smf.probesoftware.com/oldpics/i57.tinypic.com/s2acuc.jpg)
(https://smf.probesoftware.com/oldpics/i57.tinypic.com/35jcmye.jpg)
Results from initial EPMA measurements produce the following k-ratios:
6 keV 0.0298
8 keV 0.0795
15 keV 0.463
Results from MC modeling and PFE coating corrections will be posted later this week and thanks to John Armstrong for his assistance.
The coating correction is specified for both standards and unknowns within each probe run database. This way, your coating specifications cannot be modified unless you want to. For example to specify the coating parameters for your standards separately or all at once using the Standard | Edit Standard Parameters (coating) menu as seen here:
(https://smf.probesoftware.com/oldpics/i62.tinypic.com/2eg7cdg.jpg)
For your unknowns the coating parameters can also be assign to each unknown or all selected as seen here:
(https://smf.probesoftware.com/oldpics/i60.tinypic.com/14e7tyo.jpg)
These flags are always defaulted to the coating parameters defined in the Probewin.ini file, but can be modified by editing these keywords:
[standards]
StandardCoatingFlag=1 ; 0 = not coated, 1 = coated
StandardCoatingElement=6 ; assume carbon
StandardCoatingDensity=2.1
StandardCoatingThickness=200 ; in angstroms
and the coating flags for electron absorption and x-ray transmission can be turned on from the Analytical | Analysis Options as seen here:
(https://smf.probesoftware.com/oldpics/i59.tinypic.com/vmsqi8.jpg)
I re-ran the Ag coated Ti sample at 8, 9, 10, 11, 12, 13, 14, 15, 20 and 25 keV on my SX50 and after processing with STRATAGem* I obtained 119.6 nm. This compares quite well to the XRR measurement of 119.7 nm!
I call this "spurious accuracy" (credit to Joe Michael for the concept)! That is, too good to be true! ;)
In fact the STRATAGem* keV vs. K-ratio plot seems to show a small but systematic bias in the data. The student that performed the deposition and XRR thinks this is due to the Ag density at the surface of the Ti not being exactly 10.5. But for the purposes of a coating correction let us assume that the Ag film is 120 nm.
See attached documents below.
* © Copyright 1993-2016 SAMx
Here are some preliminary results comparing 6, 8 and 15 keV measurements of Ti Ka on a Ti sample coated with 120 nm of Ag (see attached spreadsheet).
(https://smf.probesoftware.com/oldpics/i60.tinypic.com/1glyz8.jpg)
As you can see the MC calculations with an assumed coating thickness of 120 nm are close, but the MC k-ratios seem to indicate a coating thickness of a little over 100 nm thickness for the Ag.
Be that as it may, we can now start to test the coating correction in Probe for EPMA... but remember, this coating correction was calibrated for 20 nm of carbon, not 120 nm of Ag! So we can assume that it will fail, but how bad will it fail and can this coating correction be improved further?
Let's start with what should be the easiest coating correction for this sample, Ti Ka underneath 120 nm of Ag, at 25 keV. Without the coating correction, we obtain the following:
Un 68 coated Ti (MVA)
TakeOff = 40.0 KiloVolt = 25.0 Beam Current = 30.0 Beam Size = 0
(Magnification (analytical) = 20000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 400)
Image Shift (X,Y): .00, .00
Pre Acquire String : mag 100000
Post Acquire String : mag 400
Number of Data Lines: 5 Number of 'Good' Data Lines: 5
First/Last Date-Time: 05/22/2014 03:19:44 AM to 05/22/2014 03:32:22 AM
Average Total Oxygen: .000 Average Total Weight%: 68.318
Average Calculated Oxygen: .000 Average Atomic Number: 22.000
Average Excess Oxygen: .000 Average Atomic Weight: 47.900
Average ZAF Iteration: 1.00 Average Quant Iterate: 2.00
Un 68 coated Ti (MVA), Results in Elemental Weight Percents
ELEM: Ti
BGDS: LIN
TIME: 80.00
BEAM: 30.14
ELEM: Ti SUM
305 68.423 68.423
306 68.206 68.206
307 68.639 68.639
308 68.538 68.538
309 67.784 67.784
AVER: 68.318 68.318
SDEV: .339 .339
SERR: .152
%RSD: .50
STDS: 2522
With a 68% total (relative to pure Ti) we can see that 120 nm of Ag significantly affects the production and emission of Ti Ka x-rays. Now we'll turn the correction on as discussed here above:
http://smf.probesoftware.com/index.php?topic=23.msg1258#msg1258
and now we obtain the following results corrected for the 120 nm of Ag on Ti:
Un 68 coated Ti (MVA)
TakeOff = 40.0 KiloVolt = 25.0 Beam Current = 30.0 Beam Size = 0
(Magnification (analytical) = 20000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 400)
Image Shift (X,Y): .00, .00
Pre Acquire String : mag 100000
Post Acquire String : mag 400
Number of Data Lines: 5 Number of 'Good' Data Lines: 5
First/Last Date-Time: 05/22/2014 03:19:44 AM to 05/22/2014 03:32:22 AM
Average Total Oxygen: .000 Average Total Weight%: 99.101
Average Calculated Oxygen: .000 Average Atomic Number: 22.000
Average Excess Oxygen: .000 Average Atomic Weight: 47.900
Average ZAF Iteration: 1.00 Average Quant Iterate: 2.00
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=Ag, Density=10.5 gm/cm3, Thickness=1200 angstroms, Sin(Thickness)=1866.87 angstroms
Un 68 coated Ti (MVA), Results in Elemental Weight Percents
ELEM: Ti
BGDS: LIN
TIME: 80.00
BEAM: 30.14
ELEM: Ti SUM
305 99.253 99.253
306 98.938 98.938
307 99.567 99.567
308 99.420 99.420
309 98.326 98.326
AVER: 99.101 99.101
SDEV: .492 .492
SERR: .220
%RSD: .50
STDS: 2522
Not bad at all, in fact it looks like "spurious accuracy" too good to be true, but let's look at the other lower voltages here in this table, which we expect to be more significant coating corrections:
(https://smf.probesoftware.com/oldpics/i59.tinypic.com/htut7a.jpg)
Clearly we got lucky on the 25 keV correction, but the lower voltages increasingly produce an over correction in the Ti concentrations, at least until the electron absorption correction goes negative!
Clearly this 20 nm carbon coating correction can be improved. Suggestions...?
John,
I am a little confused about when the modifications to the coating parameters are applied. I open the Standards coating parameters dialog from the Standard menu, modify my standard coatings (some coated with 20nm C, some uncoated), close the dialog and then recalculate the analysis, but the modified coating parameters don't seem to have been applied? What am I doing wrong?
Having modified the coatings, if I select all samples (unkn and Sts) in Analyze! open the calculations options window, then close it again, the modifications are applied, but this seems like a round about way of updating the changes.
Please enlighten me!
gareth
Happy to do so!
Basically PFE loads defaults for the standard and unknown coating parameters based on the values in the Probewin.ini file.
Then those options are disabled at a global level (you'll see why in a minute), so they are loaded but not utilized by default in the matrix corrections.
To turn on the coating parameters explicitly you need to go to the Analytical | Analysis Option menu dialog and check these options:
(https://smf.probesoftware.com/oldpics/i57.tinypic.com/2mxpctl.jpg)
Because the user will generally only be modifying their unknown coating parameters, this global flag is turned on automatically if the user edits the coating parameters in the Calculation Options dialog for unknown samples. This is explained in the post here above:
http://smf.probesoftware.com/index.php?topic=23.msg1258#msg1258
This action is similar to how specifying a spectral interference correction in the Standard Assignments dialog also turns on the global interference correction flag in Analysis Options.
Why do it like this? So every correction the software performs can be toggled on/off without having to re-specify all the sample level parameters!
Question for you: does your version have the new purple interactive Help button visible? That is in the latest version and takes you right here in the forum!
Thanks for the reply, John, but this doesn't really answer my question. When I modify the standard coatings, the new parameters are not applied, unless I go through the route I described previously.
I am running the current version, purple buttons and all!
I don't have to modify standard coatings very often, so I'll not worry about it any further.
Gareth
Quote from: Gseward on June 26, 2014, 08:37:59 PM
Thanks for the reply, John, but this doesn't really answer my question. When I modify the standard coatings, the new parameters are not applied, unless I go through the route I described previously.
Right, exactly. That is a feature (as opposed a bug)- because one doesn't often modify the standard coatings!
In other words- I want the user to specifically want the coating correction applied when simply browsing the standard coating parameters.
john
JohnD:
Can you please clarify: if the two boxes for Coating Corrections (electron energy, X-ray absorption) are NOT checked in Analysis Calculations Options, while meanwhile there are default settings for Carbon coating on both std and unknowns, is NO correction done for the carbon coating? And ONLY when the two boxes are checked, and only then, is there a correction (albeit small) made?
thanks.
JohnF
Quote from: JohnF on September 03, 2017, 09:47:18 AM
JohnD:
Can you please clarify: if the two boxes for Coating Corrections (electron energy, X-ray absorption) are NOT checked in Analysis Calculations Options, while meanwhile there are default settings for Carbon coating on both std and unknowns, is NO correction done for the carbon coating? And ONLY when the two boxes are checked, and only then, is there a correction (albeit small) made?
thanks.
JohnF
JohnF,
That is correct.
The coating element, thickness, on/off flags in the Analyze! | Calculation Options dialog are specified on a sample basis. The Analytical | Analysis Options menu dialog are a way to turn all these sample coating calculations on/off on a global basis.
JohnD
I should add that you will notice that the coating options in the Analyze! | Calculation Options dialog are disabled for standard samples.
This is because coating parameters for standards are specified from the Standard | Edit Standard Coating Parameters menu dialog as seen here:
(https://smf.probesoftware.com/gallery/395_04_09_17_11_09_36.png)
john
Probeman here.
While at M&M last week I was asked a question about analyzing standards in Probe for EPMA. That is one acquires data on a standard and then from the Analyze! window one clicks the Analyze button to get a quantitative analysis of that standard *as though it were an unknown*.
Of course if the standard is the primary (assigned) standard for that element, the element in question will iterate to the correct concentration, because the standard is analyzing itself as the standard. That is why the %VAR (percent variance) value for that element is displayed in parentheses- because it isn't really a test of the analytical quality.
More interesting is when one analyzes a standard (as an unknown from the Analyze! window), and that standard contains a non-zero concentration of an element (or a zero concentration to check for spectral interferences!), and that standard is *not* the primary standard for the element in question. Then we have the so-called secondary standard situation which is the best way to check for accuracy in EPMA.
And of course because the program knows that this sample is a standard, it can also print out the published analysis of the standard from the standard database for comparison.
But it is important to remember that for the quantification of unknowns, the only elements utilized in the primary standard are the elements that are actually assigned as the primary standard for that element. All the other elements in that standard are only useful for accuracy evaluation of major elements, or zero concentrations for interference corrections, or of course as standards for the MAN background correction.
So, when you have the situation where the standards are coated with, for example carbon, and the unknowns are not coated, say for carbon analysis of a steel, you will be analyzing the coating. So, the standard for iron might be pure Fe, and one would get an analysis (from the Analyze! window) like this:
St 526 Set 3 Iron metal
St 526 Set 3 Iron metal
TakeOff = 40.0 KiloVolt = 15.0 Beam Current = 50.0 Beam Size = 0
(Magnification (analytical) = 40000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 1572)
Image Shift (X,Y): .00, .00
From Johnson-Matthey, Vacuum remelted, Batch BM1664
Optical emission: Al < 1ppm, Ca < 1 ppm,
Cr 2 ppm, Co 20 ppm, Cu 3 ppm, Ni 3 ppm
Si 60 ppm, Sn 10 ppm, Ag < 1 ppm
Oxygen 310 ppm, Nitrogen 10 ppm
Number of Data Lines: 3 Number of 'Good' Data Lines: 3
First/Last Date-Time: 08/13/2019 01:58:46 PM to 08/13/2019 02:07:32 PM
WARNING- Using Exponential Off-Peak correction for n ka
WARNING- Using Exponential Off-Peak correction for c ka
WARNING- Using Exponential Off-Peak correction for si ka
WARNING- Using Exponential Off-Peak correction for cu ka
WARNING- Using Exponential Off-Peak correction for o ka
Average Total Oxygen: .000 Average Total Weight%: 113.447
Average Calculated Oxygen: .000 Average Atomic Number: 24.060
Average Excess Oxygen: .000 Average Atomic Weight: 41.316
Average ZAF Iteration: 5.00 Average Quant Iterate: 2.00
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms
St 526 Set 3 Iron metal, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 40.00 40.00 40.00 40.00 20.00 20.00 20.00 40.00 20.00 20.00 20.00
BEAM: 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn SUM
156 -.160 10.904 -.002 .011 -.006 .002 -.016 .357 102.982 .011 .008 114.091
157 -.085 10.732 -.020 .007 -.019 -.013 -.003 .372 101.793 -.003 -.007 112.755
158 -.285 10.792 -.025 .006 .011 -.002 .033 .432 102.560 -.019 -.009 113.495
AVER: -.177 10.809 -.016 .008 -.004 -.004 .005 .387 102.445 -.003 -.003 113.447
SDEV: .101 .087 .012 .002 .015 .007 .025 .040 .603 .015 .009 .669
SERR: .058 .050 .007 .001 .008 .004 .015 .023 .348 .009 .005
%RSD: -57.10 .81 -78.83 30.67 -328.34 -169.36 544.36 10.29 .59 -433.32 -346.16
PUBL: n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 100.000 n.a. n.a. 100.000
%VAR: --- --- --- --- --- --- --- --- (2.45) --- ---
DIFF: --- --- --- --- --- --- --- --- (2.45) --- ---
STDS: 604 506 542 514 528 523 529 913 526 524 525
STKF: .1637 .9635 .9910 1.0000 1.0000 1.0000 .9974 .2509 1.0000 .9988 1.0000
STCT: 28.99 853.49 258.45 1148.84 609.87 416.77 562.01 195.43 210.20 154.13 188.74
UNKF: -.0006 .0285 -.0001 .0001 .0000 -.0001 .0000 .0021 1.0000 .0000 .0000
UNCT: -.11 25.22 -.03 .06 -.03 -.02 .02 1.64 210.20 -.01 .00
UNBG: 1.31 .99 .39 .22 2.37 .64 2.90 2.40 .68 .28 .39
ZCOR: 2.8933 3.7968 1.1943 1.4322 1.0712 .8660 1.1135 1.8413 1.0245 .7501 1.0443
KRAW: -.0037 .0295 -.0001 .0001 .0000 -.0001 .0000 .0084 1.0000 .0000 .0000
PKBG: .92 26.40 .91 1.29 .99 .97 1.01 1.68 310.00 .98 .99
INT%: ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- -.04
Note that the total is quite high because the standard is carbon coated, and we are analyzing for carbon. And note also that the Fe concentration is wrong because we are adding 10 percent or so of carbon from the carbon coating.
But this extra carbon seen when a carbon coated standard is analyzed as an unknown, has zero effect on the standardization of unknowns because only the Fe intensities (in this standard) are being utilized for the unknown analysis. And of course we have specified in Probe for EPMA that the standards are carbon coated and the unknowns are not.
When we do this, we can analyze a uncoated sample using a standard that is carbon coated and the differences in the coating are compensated for in the matrix correction:
Un 6 H13 trav
TakeOff = 40.0 KiloVolt = 15.0 Beam Current = 50.0 Beam Size = 0
(Magnification (analytical) = 40000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 1572)
Image Shift (X,Y): .00, .00
Number of Data Lines: 5 Number of 'Good' Data Lines: 1
First/Last Date-Time: 08/13/2019 04:01:21 PM to 08/13/2019 04:27:59 PM
WARNING- Using Exponential Off-Peak correction for n ka
WARNING- Using Exponential Off-Peak correction for c ka
WARNING- Using Exponential Off-Peak correction for si ka
WARNING- Using Exponential Off-Peak correction for cu ka
WARNING- Using Exponential Off-Peak correction for o ka
WARNING- Using Time Dependent Intensity (TDI) Element Correction
Average Total Oxygen: .000 Average Total Weight%: 100.766
Average Calculated Oxygen: .000 Average Atomic Number: 24.805
Average Excess Oxygen: .000 Average Atomic Weight: 46.435
Average ZAF Iteration: 4.00 Average Quant Iterate: 3.00
No Sample Coating and/or No Sample Coating Correction
Un 6 H13 trav, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 60.00 60.00 60.00 60.00 36.00 40.00 36.00 90.00 20.00 40.00 40.00
BEAM: 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn SUM
165 3.406 2.406 1.224 .872 .194 .953 .092 .284 86.449 4.550 .334 100.766
AVER: 3.406 2.406 1.224 .872 .194 .953 .092 .284 86.449 4.550 .334 100.766
SDEV: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
SERR: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
%RSD: .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00
STDS: 604 506 542 514 528 523 529 913 526 524 525
STKF: .1637 .9635 .9910 1.0000 1.0000 1.0000 .9974 .2509 1.0000 .9988 1.0000
STCT: 29.07 853.49 258.45 1148.84 609.87 416.77 562.01 195.43 210.20 154.13 188.74
UNKF: .0142 .0061 .0103 .0061 .0018 .0107 .0008 .0015 .8480 .0573 .0032
UNCT: 3.02 5.58 2.72 7.15 1.14 4.53 .48 1.28 181.90 9.01 .62
UNBG: 1.25 .74 .32 .28 2.39 .68 2.82 2.54 .64 .29 .39
ZCOR: 2.4014 3.9407 1.1922 1.4274 1.0606 .8939 1.1019 1.8968 1.0194 .7941 1.0359
KRAW: .1040 .0065 .0105 .0062 .0019 .0109 .0009 .0066 .8654 .0585 .0033
PKBG: 3.41 8.50 9.52 26.38 1.48 7.63 1.17 1.51 283.94 32.20 2.60
INT%: ---- ---- ---- ---- ---- ---- ---- ---- .00 ---- -1.01
TDI%: .000 3.192 -.735 .000 .851 .000 .000 -4.725 2.630 .000 .000
DEV%: .0 4.6 6.6 .0 4.9 .0 .0 3.8 .4 .0 .0
TDIF: ---- LOG-LIN LOG-LIN ---- LOG-LIN ---- ---- LOG-LIN LOG-LIN ---- ----
TDIT: .00 111.00 112.00 .00 103.00 .00 .00 151.00 74.00 .00 .00
TDII: ---- 6.32 3.03 ---- 3.55 ---- ---- 3.69 183. ---- ----
TDIL: ---- 1.84 1.11 ---- 1.27 ---- ---- 1.31 5.21 ---- ----
Quote from: UofO EPMA Lab on August 13, 2019, 04:45:57 PM
While at M&M last week I was asked a question about analyzing standards in Probe for EPMA. That is one acquires data on a standard and then from the Analyze! window one clicks the Analyze button to get a quantitative analysis of that standard *as though it were an unknown*.
Of course if the standard is the primary (assigned) standard for that element, the element in question will iterate to the correct concentration, because the standard is analyzing itself as the standard. That is why the %VAR (percent variance) value for that element is displayed in parentheses- because it isn't really a test of the analytical quality.
Of course it should be pointed out that even though Probe for EPMA only utilizes the intensities of the elements actually assigned as the primary standard for that element, if one is analyzing a standard sample as an unknown in the Analyze! window, the matrix corrections will not be able to exactly converge correctly on the (ideal or published) concentration of the assigned element for this primary standard, if there is something significantly wrong with the other (unassigned) elements in that standard sample.
So in the case of our Fe (pure metal) standard shown in the previous post, because we have analyzed carbon on a carbon coated standard, of course we detect a significant amount (~10 wt%) of carbon as being in the Fe metal standard. Now the matrix iteration correctly calculates the std k-factor for our pure metal standard (the one we are analyzing as an unknown!) as being 1.0, but when it calculates the matrix correction physics for our Fe standard as containing ~10 wt% carbon, of course it cannot converge to the 100% Fe as one might expect:
St 526 Set 3 Iron metal, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 40.00 40.00 40.00 40.00 20.00 20.00 20.00 40.00 20.00 20.00 20.00
BEAM: 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn SUM
156 -.160 10.904 -.002 .011 -.006 .002 -.016 .357 102.982 .011 .008 114.091
157 -.085 10.732 -.020 .007 -.019 -.013 -.003 .372 101.793 -.003 -.007 112.755
158 -.285 10.792 -.025 .006 .011 -.002 .033 .432 102.560 -.019 -.009 113.495
AVER: -.177 10.809 -.016 .008 -.004 -.004 .005 .387 102.445 -.003 -.003 113.447
SDEV: .101 .087 .012 .002 .015 .007 .025 .040 .603 .015 .009 .669
SERR: .058 .050 .007 .001 .008 .004 .015 .023 .348 .009 .005
%RSD: -57.10 .81 -78.83 30.67 -328.34 -169.36 544.36 10.29 .59 -433.32 -346.16
PUBL: n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 100.000 n.a. n.a. 100.000
%VAR: --- --- --- --- --- --- --- --- (2.45) --- ---
DIFF: --- --- --- --- --- --- --- --- (2.45) --- ---
STDS: 604 506 542 514 528 523 529 913 526 524 525And again, this doesn't matter for any other sample that uses this Fe standard, because only the measured Fe intensities (from the standard sample), and the (ideal) composition from the standard database is being utilized for the std k-factor calculation, but if one really wants to see the composition of any carbon coated standards analyzed as though they were actual unknowns, one can simply select all the standards (except of course the carbon standard!), then click the Elements/Cations button and then click the carbon row and check the "Disable Quant" checkbox and click OK and OK. Then we will get output like this when analyzing our carbon coated standards as unknowns:
St 526 Set 3 Iron metal, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 40.00 --- 40.00 40.00 20.00 20.00 20.00 40.00 20.00 20.00 20.00
BEAM: 49.56 --- 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56 49.56
ELEM: N C-D Mo Si Ni V Cu O Fe Cr Mn SUM
156 -.124 --- -.002 .011 -.006 .002 -.016 .299 100.558 .011 .008 100.741
157 -.066 --- -.020 .007 -.018 -.012 -.003 .311 99.405 -.003 -.007 99.595
158 -.221 --- -.025 .007 .011 -.002 .032 .362 100.161 -.018 -.009 100.297
AVER: -.137 --- -.016 .008 -.004 -.004 .005 .324 100.041 -.003 -.003 100.211
SDEV: .078 --- .012 .002 .014 .007 .025 .033 .586 .014 .009 .578
SERR: .045 --- .007 .001 .008 .004 .014 .019 .338 .008 .005
%RSD: -57.14 --- -78.83 30.68 -328.37 -169.35 544.25 10.33 .59 -433.25 -346.11
PUBL: n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 100.000 n.a. n.a. 100.000
%VAR: --- --- --- --- --- --- --- --- (.04) --- ---
DIFF: --- --- --- --- --- --- --- --- (.04) --- ---
STDS: 604 --- 542 514 528 523 529 913 526 524 525
Quote from: UofO EPMA Lab on August 13, 2019, 04:45:57 PM
When we do this, we can analyze a uncoated sample using a standard that is carbon coated and the differences in the coating are compensated for in the matrix correction:
Un 6 H13 trav
TakeOff = 40.0 KiloVolt = 15.0 Beam Current = 50.0 Beam Size = 0
(Magnification (analytical) = 40000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 1572)
Image Shift (X,Y): .00, .00
Number of Data Lines: 5 Number of 'Good' Data Lines: 1
First/Last Date-Time: 08/13/2019 04:01:21 PM to 08/13/2019 04:27:59 PM
WARNING- Using Exponential Off-Peak correction for n ka
WARNING- Using Exponential Off-Peak correction for c ka
WARNING- Using Exponential Off-Peak correction for si ka
WARNING- Using Exponential Off-Peak correction for cu ka
WARNING- Using Exponential Off-Peak correction for o ka
WARNING- Using Time Dependent Intensity (TDI) Element Correction
Average Total Oxygen: .000 Average Total Weight%: 100.766
Average Calculated Oxygen: .000 Average Atomic Number: 24.805
Average Excess Oxygen: .000 Average Atomic Weight: 46.435
Average ZAF Iteration: 4.00 Average Quant Iterate: 3.00
No Sample Coating and/or No Sample Coating Correction
Un 6 H13 trav, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 60.00 60.00 60.00 60.00 36.00 40.00 36.00 90.00 20.00 40.00 40.00
BEAM: 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn SUM
165 3.406 2.406 1.224 .872 .194 .953 .092 .284 86.449 4.550 .334 100.766
AVER: 3.406 2.406 1.224 .872 .194 .953 .092 .284 86.449 4.550 .334 100.766
SDEV: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
SERR: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
%RSD: .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00
STDS: 604 506 542 514 528 523 529 913 526 524 525
STKF: .1637 .9635 .9910 1.0000 1.0000 1.0000 .9974 .2509 1.0000 .9988 1.0000
STCT: 29.07 853.49 258.45 1148.84 609.87 416.77 562.01 195.43 210.20 154.13 188.74
UNKF: .0142 .0061 .0103 .0061 .0018 .0107 .0008 .0015 .8480 .0573 .0032
UNCT: 3.02 5.58 2.72 7.15 1.14 4.53 .48 1.28 181.90 9.01 .62
UNBG: 1.25 .74 .32 .28 2.39 .68 2.82 2.54 .64 .29 .39
ZCOR: 2.4014 3.9407 1.1922 1.4274 1.0606 .8939 1.1019 1.8968 1.0194 .7941 1.0359
KRAW: .1040 .0065 .0105 .0062 .0019 .0109 .0009 .0066 .8654 .0585 .0033
PKBG: 3.41 8.50 9.52 26.38 1.48 7.63 1.17 1.51 283.94 32.20 2.60
INT%: ---- ---- ---- ---- ---- ---- ---- ---- .00 ---- -1.01
TDI%: .000 3.192 -.735 .000 .851 .000 .000 -4.725 2.630 .000 .000
DEV%: .0 4.6 6.6 .0 4.9 .0 .0 3.8 .4 .0 .0
TDIF: ---- LOG-LIN LOG-LIN ---- LOG-LIN ---- ---- LOG-LIN LOG-LIN ---- ----
TDIT: .00 111.00 112.00 .00 103.00 .00 .00 151.00 74.00 .00 .00
TDII: ---- 6.32 3.03 ---- 3.55 ---- ---- 3.69 183. ---- ----
TDIL: ---- 1.84 1.11 ---- 1.27 ---- ---- 1.31 5.21 ---- ----
And what happens if you switch on the C coating correction here? Does it change something significantly?
Hi Philipp,
Well of course if the sample was actually carbon coated, the measured carbon concentration would be much higher since we would be measuring that additional carbon, but if you're asking if the physics calculations would be different, the answer is yes.
The presence of a coating does two things. It first reduces the effective landing energy of the incident electrons, which mostly affects the calculation for low overvoltage elements such as Fe. And second it decreases the transmission of x-rays out of the sample, mostly low energy emission lines such as oxygen for example. But this latter effect can be offset by the increase in ionization efficiency due to less overvoltage for these low energy edges.
The only way to know is to do the physics calculation. The coating correction calculation in PFE is rather simple, and includes a calculation for electron energy loss from the coating material and thickness, and a calculation for x-ray absorption for the emitted x-rays. The code is on GitHub.
For the previous example I had to relocate the specific file and found that I had re-standardized since the post you quoted, so the uncoated calculation numbers are slightly different. So I will show both the uncoated and coated calculations here, first the calculation assuming the standards are coated and the sample is uncoated (the actual situation):
Un 6 H13 trav
TakeOff = 40.0 KiloVolt = 15.0 Beam Current = 50.0 Beam Size = 0
(Magnification (analytical) = 40000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 1572)
Image Shift (X,Y): .00, .00
Number of Data Lines: 5 Number of 'Good' Data Lines: 1
First/Last Date-Time: 08/13/2019 04:01:21 PM to 08/13/2019 04:27:59 PM
WARNING- Using Exponential Off-Peak correction for n ka
WARNING- Using Exponential Off-Peak correction for c ka
WARNING- Using Exponential Off-Peak correction for si ka
WARNING- Using Exponential Off-Peak correction for cu ka
WARNING- Using Exponential Off-Peak correction for o ka
WARNING- Using Time Dependent Intensity (TDI) Element Correction
Average Total Oxygen: .000 Average Total Weight%: 100.818
Average Calculated Oxygen: .000 Average Atomic Number: 24.804
Average Excess Oxygen: .000 Average Atomic Weight: 46.430
Average ZAF Iteration: 4.00 Average Quant Iterate: 3.00
No Sample Coating and/or No Sample Coating Correction
Un 6 H13 trav, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 60.00 60.00 60.00 60.00 36.00 40.00 36.00 90.00 20.00 40.00 40.00
BEAM: 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn SUM
165 3.412 2.401 1.244 .901 .197 .965 .093 .284 86.432 4.555 .335 100.818
AVER: 3.412 2.401 1.244 .901 .197 .965 .093 .284 86.432 4.555 .335 100.818
SDEV: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
SERR: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
%RSD: .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00
STDS: 604 506 542 514 528 523 529 913 526 524 525
STKF: .1637 .9635 .9910 1.0000 1.0000 1.0000 .9974 .2509 1.0000 .9988 1.0000
STCT: 29.03 855.51 254.38 1112.32 602.82 412.03 558.75 195.85 210.25 154.02 188.04
UNKF: .0142 .0061 .0104 .0063 .0019 .0108 .0008 .0015 .8478 .0573 .0032
UNCT: 3.02 5.58 2.72 7.15 1.14 4.53 .48 1.28 181.90 9.01 .62
UNBG: 1.25 .74 .32 .28 2.39 .68 2.82 2.54 .64 .29 .39
ZCOR: 2.4026 3.9431 1.1922 1.4271 1.0606 .8942 1.1019 1.8988 1.0195 .7944 1.0360
KRAW: .1041 .0065 .0107 .0064 .0019 .0110 .0009 .0066 .8652 .0585 .0033
PKBG: 3.41 8.50 9.52 26.38 1.48 7.63 1.17 1.51 283.94 32.20 2.60
INT%: ---- ---- ---- ---- ---- ---- ---- ---- .00 ---- -1.01
TDI%: .000 3.192 -.735 .000 .851 .000 .000 -4.725 2.630 .000 .000
DEV%: .0 4.6 6.6 .0 4.9 .0 .0 3.8 .4 .0 .0
TDIF: ---- LOG-LIN LOG-LIN ---- LOG-LIN ---- ---- LOG-LIN LOG-LIN ---- ----
TDIT: .00 111.00 112.00 .00 103.00 .00 .00 151.00 74.00 .00 .00
TDII: ---- 6.32 3.03 ---- 3.55 ---- ---- 3.69 183. ---- ----
TDIL: ---- 1.84 1.11 ---- 1.27 ---- ---- 1.31 5.21 ---- ----
And here the same calculation assuming that both the standards and samples are coated (and as stated above, the sample was actually not coated, so this is a physically unreal situation):
Un 6 H13 trav
TakeOff = 40.0 KiloVolt = 15.0 Beam Current = 50.0 Beam Size = 0
(Magnification (analytical) = 40000), Beam Mode = Analog Spot
(Magnification (default) = 400, Magnification (imaging) = 1572)
Image Shift (X,Y): .00, .00
Number of Data Lines: 5 Number of 'Good' Data Lines: 1
First/Last Date-Time: 08/13/2019 04:01:21 PM to 08/13/2019 04:27:59 PM
WARNING- Using Exponential Off-Peak correction for n ka
WARNING- Using Exponential Off-Peak correction for c ka
WARNING- Using Exponential Off-Peak correction for si ka
WARNING- Using Exponential Off-Peak correction for cu ka
WARNING- Using Exponential Off-Peak correction for o ka
WARNING- Using Time Dependent Intensity (TDI) Element Correction
Average Total Oxygen: .000 Average Total Weight%: 103.635
Average Calculated Oxygen: .000 Average Atomic Number: 24.695
Average Excess Oxygen: .000 Average Atomic Weight: 45.780
Average ZAF Iteration: 4.00 Average Quant Iterate: 3.00
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms
Un 6 H13 trav, Results in Elemental Weight Percents
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn
BGDS: EXP EXP LIN EXP LIN LIN EXP EXP LIN LIN LIN
TIME: 60.00 60.00 60.00 60.00 36.00 40.00 36.00 90.00 20.00 40.00 40.00
BEAM: 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49 48.49
ELEM: N C Mo Si Ni V Cu O Fe Cr Mn SUM
165 4.082 2.468 1.265 .917 .201 .984 .095 .317 88.315 4.648 .342 103.635
AVER: 4.082 2.468 1.265 .917 .201 .984 .095 .317 88.315 4.648 .342 103.635
SDEV: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
SERR: .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
%RSD: .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00
STDS: 604 506 542 514 528 523 529 913 526 524 525
STKF: .1637 .9635 .9910 1.0000 1.0000 1.0000 .9974 .2509 1.0000 .9988 1.0000
STCT: 29.03 855.51 254.38 1112.32 602.82 412.03 558.75 195.85 210.25 154.02 188.04
UNKF: .0170 .0063 .0106 .0064 .0019 .0110 .0009 .0016 .8652 .0584 .0033
UNCT: 3.02 5.58 2.72 7.15 1.14 4.53 .48 1.28 181.90 9.01 .62
UNBG: 1.25 .74 .32 .28 2.39 .68 2.82 2.54 .64 .29 .39
ZCOR: 2.3957 3.9291 1.1921 1.4258 1.0617 .8953 1.1032 1.9250 1.0208 .7955 1.0373
KRAW: .1041 .0065 .0107 .0064 .0019 .0110 .0009 .0066 .8652 .0585 .0033
PKBG: 3.41 8.50 9.52 26.38 1.48 7.63 1.17 1.51 283.94 32.20 2.60
INT%: ---- ---- ---- ---- ---- ---- ---- ---- .00 ---- -1.03
TDI%: .000 3.192 -.735 .000 .851 .000 .000 -4.725 2.630 .000 .000
DEV%: .0 4.6 6.6 .0 4.9 .0 .0 3.8 .4 .0 .0
TDIF: ---- LOG-LIN LOG-LIN ---- LOG-LIN ---- ---- LOG-LIN LOG-LIN ---- ----
TDIT: .00 111.00 112.00 .00 103.00 .00 .00 151.00 74.00 .00 .00
TDII: ---- 6.32 3.03 ---- 3.55 ---- ---- 3.69 183. ---- ----
TDIL: ---- 1.84 1.11 ---- 1.27 ---- ---- 1.31 5.21 ---- ----
As we can see, the assumption of a coated sample, when it was not actually coated, provides a poor result.
Hi John,
Thanks for replying! I think what I meant was:
You Write
Quote from: Probeman on September 18, 2019, 09:02:16 AM
No Sample Coating and/or No Sample Coating Correction
So, does it mean all coating correction is off?
Why not switch it on and define the standards as carbon coated and the unknown not?
Quote from: Philipp Poeml on September 20, 2019, 02:27:16 PM
Hi John,
Thanks for replying! I think what I meant was:
You Write
Quote from: Probeman on September 18, 2019, 09:02:16 AM
No Sample Coating and/or No Sample Coating Correction
So, does it mean all coating correction is off?
Why not switch it on and define the standards as carbon coated and the unknown not?
No, it just means that the (global) coating corrections were turned on in the Analytical | Analysis Options dialog, but that no sample coating was specified for this particular sample.
I think if you read this topic from the beginning it explains all this. For example, see here:
https://smf.probesoftware.com/index.php?topic=23.msg1402#msg1402
I see. Then I got it wrong. So coating correction was on for standards, but the sample was specified as uncoated. That makes total sense. Sorry for the confusion.
Quote from: Philipp Poeml on September 20, 2019, 03:07:54 PM
I see. Then I got it wrong. So coating correction was on for standards, but the sample was specified as uncoated. That makes total sense. Sorry for the confusion.
No worries, it's good to ask questions!
Yes. The global coating corrections (for standards and unknowns) in the Analytical | Analysis Options dialog were both turned on (energy loss and x-ray absorption from the coating), the standard sample coatings were specified in the Standard | Edit Standard Coating Parameters menu (the standard coatings are usually specified by default in the Probewin.ini file, but they are ignored if the Analysis Options parameters are not checked), and the unknown sample did not have a coating specified in the Analyze! Calculation Options dialog.
The reason the coating parameters are specified in different places for standards and unknowns is that the standards coating parameters are global, and the unknown coating parameters are specified on a sample by sample basis.
We recently were running some magnetite analyses for a customer and after standardizing we analyzed a few unknown grains and found surprisingly low totals, even after we specified calculating excess oxygen by applying the method of Droop (1987) as described in this post:
https://smf.probesoftware.com/index.php?topic=92.msg8593#msg8593
Un 41 Chill-9 Mgt-Ilm 1_MGT Replace, Results in Elemental Weight Percents
ELEM: Fe Mg Ti V Mn Cr Al Si Ca O
TYPE: ANAL ANAL ANAL ANAL ANAL ANAL ANAL ANAL ANAL CALC
BGDS: MAN MAN MAN MAN MAN MAN MAN MAN MAN
TIME: 50.00 120.00 80.00 60.00 60.00 60.00 60.00 60.00 40.00 ---
BEAM: 50.35 50.35 50.35 50.35 50.35 50.35 50.35 50.35 50.35 ---
ELEM: Fe Mg Ti V Mn Cr Al Si Ca O SUM
469 53.826 1.046 9.557 .275 .423 -.002 1.061 .038 .013 26.413 92.650
470 53.689 1.039 9.748 .265 .419 .001 1.057 .039 .012 26.434 92.702
471 53.788 1.046 9.764 .274 .419 .003 1.067 .043 .021 26.500 92.925
472 53.684 1.040 9.588 .260 .423 -.007 1.064 .051 .044 26.390 92.535
473 53.646 1.042 9.752 .264 .427 -.003 1.079 .044 .057 26.462 92.770
474 53.809 1.048 9.729 .267 .432 -.008 1.047 .036 .055 26.500 92.913
475 53.318 1.058 9.764 .272 .424 -.013 1.027 .092 .066 26.375 92.385
476 53.640 1.056 10.168 .270 .433 -.005 .989 .026 .037 26.600 93.214
477 53.530 1.076 10.094 .270 .428 -.005 .987 .029 .035 26.541 92.986
478 53.220 1.084 10.430 .262 .437 .003 .962 .036 .045 26.583 93.061
479 52.999 1.083 10.291 .243 .438 .000 .952 .041 .024 26.421 92.492
AVER: 53.559 1.056 9.899 .266 .428 -.003 1.026 .043 .037 26.474 92.785
SDEV: .268 .017 .295 .009 .007 .005 .046 .018 .018 .077 .259
SERR: .081 .005 .089 .003 .002 .001 .014 .005 .005 .023
%RSD: .50 1.61 2.98 3.43 1.58 -154.27 4.47 40.66 48.92 .29
STDS: 395 12 22 23 25 24 306 14 306 ---
So of course we first tried to analyzed some standards as unknowns and they came out just fine. Well it turned out that this user had carbon coated their thin sections themselves and because they weren't quite sure of the procedure they apparently laid on a *very* thick coat of carbon. After we removed the thin section from the probe it did indeed appear to be quite dark, so we walked over to the stylus profilometer and measured the carbon coat, after scratching some areas clean with a razor blade. And lo and behold, indeed we had close to 70 nm of carbon on these thin sections! :o
So we went back to the probe and turned on the coating correction in the Analysis Options menu by checking the two boxes as described here:
https://smf.probesoftware.com/index.php?topic=23.msg1402#msg1402
and then we specified this extra thick carbon coat in the Calculation Options as shown here:
(https://smf.probesoftware.com/gallery/395_21_01_20_4_41_32.png)
and now we analyze the sample again and now it's much better:
Un 41 Chill-9 Mgt-Ilm 1_MGT Replace, Results in Elemental Weight Percents
ELEM: Fe Mg Ti V Mn Cr Al Si Ca O
TYPE: ANAL ANAL ANAL ANAL ANAL ANAL ANAL ANAL ANAL CALC
BGDS: MAN MAN MAN MAN MAN MAN MAN MAN MAN
TIME: 50.00 120.00 80.00 60.00 60.00 60.00 60.00 60.00 40.00 ---
BEAM: 50.35 50.35 50.35 50.35 50.35 50.35 50.35 50.35 50.35 ---
ELEM: Fe Mg Ti V Mn Cr Al Si Ca O SUM
469 57.884 1.137 10.181 .287 .453 -.003 1.142 .040 .014 28.369 99.504
470 57.736 1.129 10.384 .276 .449 .001 1.137 .042 .013 28.391 99.556
471 57.842 1.137 10.401 .286 .449 .003 1.148 .046 .022 28.462 99.796
472 57.731 1.130 10.214 .270 .453 -.008 1.144 .054 .047 28.343 99.379
473 57.690 1.133 10.389 .275 .458 -.004 1.161 .047 .061 28.420 99.629
474 57.865 1.139 10.364 .278 .463 -.009 1.126 .039 .058 28.461 99.784
475 57.338 1.150 10.402 .283 .455 -.014 1.105 .098 .070 28.327 99.214
476 57.683 1.148 10.832 .281 .464 -.005 1.064 .028 .039 28.567 100.101
477 57.565 1.169 10.753 .281 .459 -.006 1.062 .031 .037 28.504 99.857
478 57.232 1.178 11.111 .273 .468 .003 1.035 .038 .048 28.547 99.933
479 56.994 1.177 10.963 .252 .470 .000 1.024 .044 .026 28.374 99.324
AVER: 57.596 1.148 10.545 .277 .458 -.004 1.104 .046 .040 28.433 99.643
SDEV: .289 .018 .314 .010 .007 .005 .049 .019 .019 .082 .277
SERR: .087 .006 .095 .003 .002 .002 .015 .006 .006 .025
%RSD: .50 1.61 2.98 3.54 1.58 -143.60 4.47 40.64 48.93 .29
STDS: 395 12 22 23 25 24 306 14 306 ---
Note that the reason for Fe being so affected by this extra thick carbon coat is not due to x-ray absorption. The major effect is from electron energy loss from this extra thick carbon coat and hence a significantly lower landing energy for the incident electrons. This lowers the overvoltage (at 15 keV) significantly enough to cause the previously observed low totals.
Just for fun, here is the excess oxygen calculation along with the oxide and cation output:
Ferrous/Ferric Calculation Results:
Ferric/TotalFe FeO Fe2O3 Oxygen from Fe2O3
469 .350 48.405 28.964 2.902
470 .344 48.734 28.388 2.844
471 .343 48.877 28.381 2.843
472 .349 48.386 28.767 2.882
473 .343 48.764 28.288 2.834
474 .347 48.585 28.737 2.879
475 .342 48.516 28.060 2.811
476 .338 49.150 27.850 2.790
477 .340 48.911 27.946 2.800
478 .330 49.348 26.984 2.704
479 .333 48.892 27.151 2.720
AVER: .342 48.779 28.138 2.819
Un 41 Chill-9 Mgt-Ilm 1_MGT Replace, Results in Oxide Weight Percents
ELEM: FeO MgO TiO2 V2O3 MnO Cr2O3 Al2O3 SiO2 CaO O SUM
469 74.467 1.885 16.982 .423 .585 -.004 2.157 .087 .020 2.902 99.504
470 74.278 1.872 17.322 .406 .579 .001 2.148 .089 .018 2.844 99.556
471 74.414 1.886 17.350 .420 .580 .004 2.169 .099 .031 2.843 99.796
472 74.271 1.874 17.038 .398 .585 -.012 2.162 .116 .065 2.882 99.379
473 74.218 1.878 17.329 .405 .591 -.005 2.193 .101 .085 2.834 99.629
474 74.443 1.889 17.288 .409 .597 -.013 2.127 .083 .082 2.879 99.784
475 73.765 1.907 17.351 .417 .587 -.020 2.087 .210 .099 2.811 99.214
476 74.210 1.903 18.068 .414 .600 -.008 2.009 .060 .055 2.790 100.101
477 74.057 1.939 17.937 .414 .592 -.008 2.007 .067 .052 2.800 99.857
478 73.629 1.953 18.534 .401 .604 .005 1.955 .081 .067 2.704 99.933
479 73.322 1.951 18.288 .370 .607 .000 1.934 .095 .036 2.720 99.324
AVER: 74.097 1.903 17.590 .407 .592 -.005 2.086 .099 .055 2.819 99.643
SDEV: .371 .031 .524 .014 .009 .008 .093 .040 .027 .063 .277
SERR: .112 .009 .158 .004 .003 .002 .028 .012 .008 .019
%RSD: .50 1.61 2.98 3.54 1.58 -143.60 4.47 40.64 48.93 2.25
STDS: 395 12 22 23 25 24 306 14 306 ---
Un 41 Chill-9 Mgt-Ilm 1_MGT Replace, Results Based on Sum of 3 Cations
ELEM: Fe Mg Ti V Mn Cr Al Si Ca O SUM
469 2.297 .104 .471 .013 .018 .000 .094 .003 .001 3.929 6.929
470 2.290 .103 .480 .012 .018 .000 .093 .003 .001 3.930 6.930
471 2.288 .103 .480 .012 .018 .000 .094 .004 .001 3.929 6.929
472 2.293 .103 .473 .012 .018 .000 .094 .004 .003 3.930 6.930
473 2.285 .103 .480 .012 .018 .000 .095 .004 .003 3.929 6.929
474 2.290 .104 .478 .012 .019 .000 .092 .003 .003 3.931 6.931
475 2.280 .105 .482 .012 .018 -.001 .091 .008 .004 3.932 6.932
476 2.276 .104 .498 .012 .019 .000 .087 .002 .002 3.934 6.934
477 2.276 .106 .496 .012 .018 .000 .087 .002 .002 3.934 6.934
478 2.261 .107 .512 .012 .019 .000 .085 .003 .003 3.936 6.936
479 2.265 .107 .508 .011 .019 .000 .084 .003 .001 3.937 6.937
AVER: 2.282 .104 .487 .012 .018 .000 .091 .004 .002 3.932 6.932
SDEV: .011 .002 .014 .000 .000 .000 .004 .001 .001 .003 .003
SERR: .003 .001 .004 .000 .000 .000 .001 .000 .000 .001
%RSD: .50 1.59 2.88 3.47 1.53 -143.63 4.54 40.88 48.99 .07
Greetings!
I try to learn use the coating thickness option and made some tests.
I used 2 standards of Au in different blocks with different thickness of carbon coating:
Standard 1 - main standard, standard 2 - standard as unknown.
My results (% wt Au):
1. options do not "ON" (Analytical/Analysis options) (wt%): Standard 1 - 100.011 / Standard 2 - 101.757
2. options "ON" (Analytical/Analysis options), (wt%): Standard 1 (100 A) - 102.205 / Standard 2 (200 A) - 103.989
Standard 1 (200 A) - 100.011 / Standard 2 (200 A) - 101.757
Standard 1 (300 A) - 97.817 / Standard 2 (200 A) - 99.525
3. Also options "ON" (Analytical/Analysis options), (wt%): Standard 1 (200 A) - 100.011 / Standard 2 (100 A) - 101.757
Standard 1 (200 A) - 100.011 / Standard 2 (200 A) - 101.757
Standard 1 (200 A) - 100.011 / Standard 2 (300 A) - 101.757
So, it means (please, correct me if I wrong):
-if options "OFF" (Analytical/Analysis options), the system uses the correction with default (200 A) coating thickness of main standard.
-the system do not use the correction for standards which are not using as main standards. Because these standards are not "unknowns" and and these standards do not standardize.
Is it correct?
Thank you.
Please read carefully this whole topic.
It is difficult to understand what you are doing without more information. For example, in addition to turning on the coating corrections for electron energy loss and x-ray absorption in the Analytical | Analysis Options dialog, did you specify the standard coating in the Standard menu and also the unknown coating for the standard as an unknown in the Analyze! | Calculation Options dialog?
Quote from: John Donovan on January 18, 2023, 08:47:31 AM
Please read carefully this whole topic.
Of course, many times ))
Quote from: John Donovan on January 18, 2023, 08:47:31 AM
It is difficult to understand what you are doing without more information. For example, in addition to turning on the coating corrections for electron energy loss and x-ray absorption in the Analytical | Analysis Options dialog, did you specify the standard coating in the Standard menu
Of course, I choose in "Standard/Edit Standard coating parameters" "use coating" checkbox and thickness 100, 200 or 300 A which I noted in my question.
I can see that system uses "coating correction" with correct Thickness in main window of PFE with all other calculation results.
Quote from: John Donovan on January 18, 2023, 08:47:31 AM
... and also the unknown coating for the standard as an unknown in the Analyze! | Calculation Options dialog?
It is impossible because I work only with standards:
Standard 1 - is a main standard
Standard 2 - is also a standard but it is not using for standardize and its composition calculated based on Standard 1
Quote from: Rom on January 18, 2023, 04:59:45 PM
Quote from: John Donovan on January 18, 2023, 08:47:31 AM
... and also the unknown coating for the standard as an unknown in the Analyze! | Calculation Options dialog?
It is impossible because I work only with standards:
Standard 1 - is a main standard
Standard 2 - is also a standard but it is not using for standardize and its composition calculated based on Standard 1
OK, I think that is the problem.
Try running the unassigned standard (with the different coating thickness) as an unknown, and specify the coating on that material using the Calculation Options dialog.
Yes, of course it works good. I did it many times.
But in the case like I asked I see
1. System uses "coating correction" (coating thickness by default, 200A) even if my checkboxes in Analytical/Analysis options are OFF.
2. System does not use "coating correction" with coating thickness different of default for unassigned standard.
Quote from: Rom on January 18, 2023, 07:21:11 PM
Yes, of course it works good. I did it many times.
But in the case like I asked I see
1. System uses "coating correction" (coating thickness by default, 200A) even if my checkboxes in Analytical/Analysis options are OFF.
Yes. The system applies the coating correction based on the flags in the Analytical | Analysis Options flags.
Quote from: Rom on January 18, 2023, 07:21:11 PM
2. System does not use "coating correction" with coating thickness different of default for unassigned standard.
The standards would need to have different standard numbers if you do not acquire them as unknowns. Try acquiring them as unknowns and let me know how that works.
1. Unfortunately even if flags OFF, the system uses the correction. I showed upper the same result with and without flags in Analytical/Analysis Options.
2. Of course my standards 1 & 2 have different Standard numbers because they are different ))).
If I'll use standard 2 like Unknown - everything will good.
Quote from: Rom on January 19, 2023, 02:59:10 AM
1. Unfortunately even if flags OFF, the system uses the correction. I showed upper the same result with and without flags in Analytical/Analysis Options.
2. Of course my standards 1 & 2 have different Standard numbers because they are different ))).
If I'll use standard 2 like Unknown - everything will good.
Is that last sentence a question?
I checked the coating corrections just now and they appear to be working fine. For example, look at the Ca concentration in this feldspar standard without a coating correction (using anorthite as a primary Ca standard):
St 305 Set 1 Labradorite (Lake Co.), Results in Elemental Weight Percents
ELEM: Al Fe Si Na Ca K Mg O
TYPE: ANAL ANAL ANAL ANAL ANAL SPEC SPEC SPEC
BGDS: EXP LIN EXP LIN LIN
TIME: 10.00 10.00 10.00 10.00 10.00 --- --- ---
BEAM: 30.02 30.02 30.02 30.02 30.02 --- --- ---
ELEM: Al Fe Si Na Ca K Mg O SUM
131 16.524 .526 24.125 2.988 9.695 .100 .084 46.823 100.866
132 16.566 .468 23.898 3.044 9.698 .100 .084 46.823 100.680
133 16.566 .586 23.851 2.923 9.719 .100 .084 46.823 100.653
134 16.459 .516 24.216 3.022 9.552 .100 .084 46.823 100.773
135 16.587 .518 24.262 2.929 9.541 .100 .084 46.823 100.843
AVER: 16.540 .523 24.070 2.981 9.641 .100 .084 46.823 100.763
SDEV: .051 .042 .186 .054 .087 .000 .000 .000 .095
SERR: .023 .019 .083 .024 .039 .000 .000 .000
%RSD: .31 8.05 .77 1.82 .90 .00 .00 .00
PUBL: 16.359 .319 23.957 2.841 9.577 .100 .084 46.823 100.060
%VAR: 1.11 63.89 .47 4.94 .67 .00 .00 .00
DIFF: .181 .204 .113 .140 .064 .000 .000 .000
STDS: 13 26 14 301 306 --- --- ---
I now set the carbon coating thickness for the anorthite standard from 200 angstroms to 400 angstroms (making sure to click the Apply Parameters to Selected Standard button from the Standard | Edit Standard Coating Parameters menu:
St 305 Set 1 Labradorite (Lake Co.), Results in Elemental Weight Percents
ELEM: Al Fe Si Na Ca K Mg O
TYPE: ANAL ANAL ANAL ANAL ANAL SPEC SPEC SPEC
BGDS: EXP LIN EXP LIN LIN
TIME: 10.00 10.00 10.00 10.00 10.00 --- --- ---
BEAM: 30.02 30.02 30.02 30.02 30.02 --- --- ---
ELEM: Al Fe Si Na Ca K Mg O SUM
131 16.524 .526 24.125 2.988 9.695 .100 .084 46.823 100.866
132 16.566 .468 23.898 3.044 9.698 .100 .084 46.823 100.680
133 16.566 .586 23.851 2.923 9.719 .100 .084 46.823 100.653
134 16.459 .516 24.216 3.022 9.552 .100 .084 46.823 100.773
135 16.587 .518 24.262 2.929 9.541 .100 .084 46.823 100.843
AVER: 16.540 .523 24.070 2.981 9.641 .100 .084 46.823 100.763
SDEV: .051 .042 .186 .054 .087 .000 .000 .000 .095
SERR: .023 .019 .083 .024 .039 .000 .000 .000
%RSD: .31 8.05 .77 1.82 .90 .00 .00 .00
PUBL: 16.359 .319 23.957 2.841 9.577 .100 .084 46.823 100.060
%VAR: 1.11 63.89 .47 4.94 .67 .00 .00 .00
DIFF: .181 .204 .113 .140 .064 .000 .000 .000
STDS: 13 26 14 301 306 --- --- ---
No change, right? Because I didn't yet turn on the *two* coating parameter flags from the Analytical | Analysis Options dialog, as I do now (that is, Use Conductive Coating Correction for Electron Absorption and Use Conductive Coating Correction for X-Ray Transmission):
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=1.35 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms
St 305 Set 1 Labradorite (Lake Co.), Results in Elemental Weight Percents
ELEM: Al Fe Si Na Ca K Mg O
TYPE: ANAL ANAL ANAL ANAL ANAL SPEC SPEC SPEC
BGDS: EXP LIN EXP LIN LIN
TIME: 10.00 10.00 10.00 10.00 10.00 --- --- ---
BEAM: 30.02 30.02 30.02 30.02 30.02 --- --- ---
ELEM: Al Fe Si Na Ca K Mg O SUM
131 16.523 .526 24.127 2.987 9.589 .100 .084 46.823 100.760
132 16.564 .468 23.900 3.043 9.592 .100 .084 46.823 100.574
133 16.564 .586 23.854 2.923 9.613 .100 .084 46.823 100.546
134 16.458 .516 24.219 3.022 9.447 .100 .084 46.823 100.669
135 16.585 .518 24.264 2.928 9.436 .100 .084 46.823 100.739
AVER: 16.539 .523 24.073 2.980 9.536 .100 .084 46.823 100.658
SDEV: .051 .042 .186 .054 .086 .000 .000 .000 .095
SERR: .023 .019 .083 .024 .039 .000 .000 .000
%RSD: .31 8.05 .77 1.82 .90 .00 .00 .00
PUBL: 16.359 .319 23.957 2.841 9.577 .100 .084 46.823 100.060
%VAR: 1.10 63.89 .48 4.91 -.43 .00 .00 .00
DIFF: .180 .204 .116 .139 -.041 .000 .000 .000
STDS: 13 26 14 301 306 --- --- ---
Note the two statements just before the analysis results showing the coating parameters for this secondary standard are being utilized and now the results are different for Ca. Now I turn off those those conductive coating corrections in the Analytical | Analysis Options dialog and the results are the same as originally:
St 305 Set 1 Labradorite (Lake Co.), Results in Elemental Weight Percents
ELEM: Al Fe Si Na Ca K Mg O
TYPE: ANAL ANAL ANAL ANAL ANAL SPEC SPEC SPEC
BGDS: EXP LIN EXP LIN LIN
TIME: 10.00 10.00 10.00 10.00 10.00 --- --- ---
BEAM: 30.02 30.02 30.02 30.02 30.02 --- --- ---
ELEM: Al Fe Si Na Ca K Mg O SUM
131 16.524 .526 24.125 2.988 9.695 .100 .084 46.823 100.866
132 16.566 .468 23.898 3.044 9.698 .100 .084 46.823 100.680
133 16.566 .586 23.851 2.923 9.719 .100 .084 46.823 100.653
134 16.459 .516 24.216 3.022 9.552 .100 .084 46.823 100.773
135 16.587 .518 24.262 2.929 9.541 .100 .084 46.823 100.843
AVER: 16.540 .523 24.070 2.981 9.641 .100 .084 46.823 100.763
SDEV: .051 .042 .186 .054 .087 .000 .000 .000 .095
SERR: .023 .019 .083 .024 .039 .000 .000 .000
%RSD: .31 8.05 .77 1.82 .90 .00 .00 .00
PUBL: 16.359 .319 23.957 2.841 9.577 .100 .084 46.823 100.060
%VAR: 1.11 63.89 .47 4.94 .67 .00 .00 .00
DIFF: .181 .204 .113 .140 .064 .000 .000 .000
STDS: 13 26 14 301 306 --- --- ---
I don't know what you are doing wrong, but again without more information it's difficult to tell. I suggest re-reading this topic more carefully.
Ok. Lets look at my 2 questions separately. So, firstly only question #1.
If you take your "start" results and turn on the *two* coating parameter flags from the Analytical | Analysis Options dialog WITHOUT changing carbon coating thickness for the anorthite standard from 200 angstroms to 400 angstroms in Standard menu
nothing will change - right?
It means coating parameters by default (200A) used in any case: OFF or ON *two* coating parameter flags from the Analytical | Analysis Options dialog - right?
Quote from: Rom on January 19, 2023, 04:20:06 PM
Ok. Lets look at my 2 questions separately. So, firstly only question #1.
If you take your "start" results and turn on the *two* coating parameter flags from the Analytical | Analysis Options dialog WITHOUT changing carbon coating thickness for the anorthite standard from 200 angstroms to 400 angstroms in Standard menu
nothing will change - right?
It means coating parameters by default (200A) used in any case: OFF or ON *two* coating parameter flags from the Analytical | Analysis Options dialog - right?
If the coating material and thickness on the two samples are the same, then yes, the results will be (essentially) the same whether you assume a coating correction or not.
If the coating material and thickness are not the same, then again yes, you must declare the coating material and thickness for each sample and turn on the coating correction flags.
Yes, you are right.
If we turn on the *two* coating parameter flags from the Analytical | Analysis Options dialog - both: Standard and Unknown will use the correction. So if the coating thickness for both: Standard and Unknown will the same, the results before and after turn on the *two* coating parameter flags will the same.
It is clear.
But why composition of Standard is not changing independent turn on or turn off the *two* coating parameter flags from the Analytical | Analysis Options dialog?
Composition of Standard will change ONLY if we change default 200A thickness (doesn't matter decrease or increase: 201 and more or 199 and less).
Quote from: Rom on January 19, 2023, 05:59:08 PM
Yes, you are right.
If we turn on the *two* coating parameter flags from the Analytical | Analysis Options dialog - both: Standard and Unknown will use the correction. So if the coating thickness for both: Standard and Unknown will the same, the results before and after turn on the *two* coating parameter flags will the same.
It is clear.
But why composition of Standard is not changing independent turn on or turn off the *two* coating parameter flags from the Analytical | Analysis Options dialog?
Composition of Standard will change ONLY if we change default 200A thickness (doesn't matter decrease or increase: 201 and more or 199 and less).
Normally we do not utilize the coating correction because if both the standard and secondary standard (or unknown) have the same coating material and thickness, then as I stated in my previous post, the effects of the coatings essentially normalize out. Remember, everything in microanalysis is a ratio between the primary standard and the secondary standard (or unknown).
However there are two situations where the effects of the coatings can be slightly larger, even if the coatings are the same for both samples because these effects are non-linear. First, when we have a situation where the emitted (measured) x-ray is highly absorbed by the coating material, for example O Ka absorbed by carbon (MAC = ~12,000). And second where there is a low over-voltage situation, such as Fe Ka at say 8 keV, due to the energy loss of the electron beam.
Yes, thank you. I expected this affect.
Do you have any ideas which can help me to understand, why composition of Standard is not changing independent turn on or turn off the *two* coating parameter flags from the Analytical | Analysis Options dialog?
Composition of Standard will change ONLY if we change default 200A thickness (doesn't matter decrease or increase: 201 and more or 199 and less).
Quote from: Rom on January 19, 2023, 10:42:47 PM
Yes, thank you. I expected this affect.
Do you have any ideas which can help me to understand, why composition of Standard is not changing independent turn on or turn off the *two* coating parameter flags from the Analytical | Analysis Options dialog?
Composition of Standard will change ONLY if we change default 200A thickness (doesn't matter decrease or increase: 201 and more or 199 and less).
Yes, the composition of the secondary standard (or unknown) will not change if the primary standard and the secondary standard (or unknown) have the same coating material and thickness, regardless of the Conductive Coating settings in the Analytical |Analysis Options dialog.
Yes, but why composition of the main (not secondary) doesn't change without default cover thickness changing?
Quote from: Rom on January 22, 2023, 04:08:35 PM
Yes, but why composition of the main (not secondary) doesn't change without default cover thickness changing?
Because the primary standard always has the composition of the published value. That's what it means to be a primary standard.
But if the primary standard will have coating with thickness (chosen in PFE) 199 and less or 201 and more A, the calculated composition will change. Why the calculated composition will not change with thickness (chosen in PFE) exactly 200A?
Quote from: Rom on January 22, 2023, 06:45:14 PM
But if the primary standard will have coating with thickness (chosen in PFE) 199 and less or 201 and more A, it calculated composition will change. Why the calculated composition will not change with thickness (chosen in PFE) exactly 200A?
Hi Rom,
You are exactly correct!
Apparently I've only tested situations where the standard was uncoated and the unknown was coated with various coatings, or both the standard and the unknown were coated the same (various) coatings, or the standards were coated with the default value of 200 angstroms of carbon and the unknowns coated with (various) coatings (generally the situation in my lab!), and of course for all of these scenarios the coating corrections were turned on.
In the situation you described where the primary standard was coated with a value different than the default coating (200 angstroms of carbon), *and* the standard was analyzed as an unknown *and* the coating correction flags in the Analytical | Analysis Options dialog were turned on, then a problem can be seen. Though it's possible that the difference in the coatings thicknesses were small enough to not be noticed, so "good catch"! ;D
Of course normally we use the same coating on both standards and unknowns and usually we never turn on the coating corrections, so all this time no one (until you) has noticed this issue.
Update Probe for EPMA from the Help menu and you will get this coating bug fix for standards analyzed as unknowns with non-default coatings specified.
Basically, the problem was in the calculation of the "primary" (pure element intensities in routine ZAFSetZAF) when the sample was a standard with a non-standard coating thickness and analyzed as an unknown.
Here is what the old code showed when the standard was coated with 200 angstroms of carbon and analyzed with the coating corrections turned on:
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=1.35 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms
St 522 Set 2 Titanium metal, Results in Elemental Weight Percents
ELEM: Ti O
TYPE: ANAL ANAL
BGDS: LIN LIN
TIME: 10.00 10.00
BEAM: 30.01 30.01
ELEM: Ti O SUM
106 99.276 .711 99.988
107 99.842 .679 100.521
108 99.300 .609 99.908
109 99.230 .554 99.784
110 99.987 .639 100.626
AVER: 99.527 .638 100.165
SDEV: .359 .061 .381
SERR: .160 .027
%RSD: .36 9.60
PUBL: 99.500 .500 100.000
%VAR: (.03) 27.63
DIFF: (.03) .138
STDS: 522 12
No problems with this analysis. And here with the standard coating set to 190 angstroms (again with the old code):
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=1.35 gm/cm3, Thickness=190 angstroms, Sin(Thickness)=295.5877 angstroms
St 522 Set 2 Titanium metal, Results in Elemental Weight Percents
ELEM: Ti O
TYPE: ANAL ANAL
BGDS: LIN LIN
TIME: 10.00 10.00
BEAM: 30.01 30.01
ELEM: Ti O SUM
106 99.333 .713 100.047
107 99.900 .681 100.580
108 99.357 .611 99.967
109 99.287 .555 99.842
110 100.045 .641 100.685
AVER: 99.584 .640 100.224
SDEV: .359 .061 .382
SERR: .160 .027
%RSD: .36 9.60
PUBL: 99.500 .500 100.000
%VAR: (.08) 28.02
DIFF: (.08) .140
STDS: 522 12
OK, it is a little different, but perhaps we can see why this was never noticed previously!
Now the same analysis but with the corrected code where the actual standard coating parameters are now loaded in the "primary intensity" calculation when the sample is a standard:
Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=1.35 gm/cm3, Thickness=190 angstroms, Sin(Thickness)=295.5877 angstroms
St 522 Set 2 Titanium metal, Results in Elemental Weight Percents
ELEM: Ti O
TYPE: ANAL ANAL
BGDS: LIN LIN
TIME: 10.00 10.00
BEAM: 30.01 30.01
ELEM: Ti O SUM
106 99.276 .711 99.988
107 99.842 .679 100.521
108 99.300 .609 99.908
109 99.230 .554 99.784
110 99.987 .639 100.626
AVER: 99.527 .638 100.165
SDEV: .359 .061 .381
SERR: .160 .027
%RSD: .36 9.60
PUBL: 99.500 .500 100.000
%VAR: (.03) 27.63
DIFF: (.03) .138
STDS: 522 12
Now we get the same result as before when all standards are coated with 200 angstroms of carbon! And finally here again, but
without any coating corrections turned on:
No Sample Coating and/or No Sample Coating Correction
St 522 Set 2 Titanium metal, Results in Elemental Weight Percents
ELEM: Ti O
TYPE: ANAL ANAL
BGDS: LIN LIN
TIME: 10.00 10.00
BEAM: 30.01 30.01
ELEM: Ti O SUM
106 99.276 .711 99.988
107 99.842 .679 100.521
108 99.300 .609 99.908
109 99.230 .554 99.784
110 99.987 .639 100.626
AVER: 99.527 .638 100.165
SDEV: .359 .061 .381
SERR: .160 .027
%RSD: .36 9.60
PUBL: 99.500 .500 100.000
%VAR: (.03) 27.63
DIFF: (.03) .138
STDS: 522 12
Again, the same result because all standards have the same coating!
Remember, in situations of very high x-ray absorption by the coating, or in very low over voltage situations, the elemental compositions may be somewhat different due to differences in the coating physics between the primary and secondary (or unknown) compositions.
Hello!
I met with some accounting issue with carbon coating thickness again.
Could you explain why changing carbon coating thickness on one standard doesn't change composition of this and other standards.
For instance, we use 2 standards: MgO and Magnetite.
We set MgO like oxygen standard for both of them (for MgO and for Magnetite).
Initially carbon coating thickness for both of them 200A.
But measured oxygen composition in MgO and Magnetite standards will not change if we'll change carbon coating thickness on MgO or on Magnetite standards.
At the same time if we change carbon coating thickness on MgO standard, oxygen composition in unknowns will change logically.
Quote from: Rom on October 19, 2023, 01:45:05 AM
Hello!
I met with some accounting issue with carbon coating thickness again.
Could you explain why changing carbon coating thickness on one standard doesn't change composition of this and other standards.
For instance, we use 2 standards: MgO and Magnetite.
We set MgO like oxygen standard for both of them (for MgO and for Magnetite).
Initially carbon coating thickness for both of them 200A.
But measured oxygen composition in MgO and Magnetite standards will not change if we'll change carbon coating thickness on MgO or on Magnetite standards.
At the same time if we change carbon coating thickness on MgO standard, oxygen composition in unknowns will change logically.
If one of the standards is the primary standard for oxygen, the oxygen composition should not change. Did you select the two "use coating correction" options in the Analytical | Analysis Options dialog?
Quote from: John Donovan on October 19, 2023, 07:57:25 AM
Quote from: Rom on October 19, 2023, 01:45:05 AM
Hello!
I met with some accounting issue with carbon coating thickness again.
Could you explain why changing carbon coating thickness on one standard doesn't change composition of this and other standards.
For instance, we use 2 standards: MgO and Magnetite.
We set MgO like oxygen standard for both of them (for MgO and for Magnetite).
Initially carbon coating thickness for both of them 200A.
But measured oxygen composition in MgO and Magnetite standards will not change if we'll change carbon coating thickness on MgO or on Magnetite standards.
At the same time if we change carbon coating thickness on MgO standard, oxygen composition in unknowns will change logically.
If one of the standards is the primary standard for oxygen, the oxygen composition should not change. Did you select the two "use coating correction" options in the Analytical | Analysis Options dialog?
OK, this was caused by a silly mistake in the code and is now fixed. Nice catch!
Please update using the Help menu to the latest 13.6.0 of PFE and it will now work as expected.
Thank you very much, it works right.