Standard/ unknown different coating?

[John Donovan]

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.

[Rom]

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?

[John Donovan]

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.

[Rom]

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).

[John Donovan]

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.

[Rom]

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).

[John Donovan]

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.

[Rom]

Yes, but why composition of the main (not secondary) doesn't change without default cover thickness changing?

[John Donovan]

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.

[Rom]

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?

[John Donovan]

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"!   

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.

[Rom]

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.

[John Donovan]

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? 

[John Donovan]

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.

[Rom]

Thank you very much, it works right.