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.