Time Dependent Intensity (TDI) Corrections

[John Donovan]

Here are the same data but with the "TDI weighting" feature applied as seen here:

So is it worth allowing more than a factor of 10 "weighting" to the initial TDI measured points?

[Probeman]

Was wondering if I could throw a quick question to the group about combining TDI's and multiple setups/samples using the nice "Combine Selected Samples" option in Analyze. Apologies if this has already been discussed elsewhere, but I haven't been able to find mention of this error message in either the documentation or other forum threads.

For this particular project, I have two Unknown samples to combine. Each was run with different sample setup (i.e. different element and beam conditions). TDI's were enabled for both setups, and there are no duplicate elements between each setup.
Thanks,
OKN

Hi Owen,
This is fixed now, but in a slightly different manner than you might have been expecting.

When the samples are combined using the Analyze! | Combine Selected Samples button, a temporary sample is created with the elements from all selected samples.  The problem with TDI is that the TDI is actually based on the sample number and data row and channel.  But since the TDI data for a combined sample comes from multiple samples there is no way indicate where the TDI intensities should be loaded from once the channels are combined.

So you have two samples selected at different beam energies, both with TDI acquisition, first sample here:

Un    3 SON68_20kV, Results in Elemental Weight Percents

ELEM:       Ba      La      Ce      Pr      Cr      Nd      Mn      Fe      Ni      Zn      Ca      Te      Cs       O       H      Li
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    CALC    SPEC    DIFF
BGDS:      LIN     LIN    S-Lo     LIN     LIN     LIN     LIN     LIN     LIN     LIN     EXP     LIN     EXP
TIME:    30.00   30.00   30.00   30.00   30.00   30.00   40.00   20.00   40.00   20.00   40.00   60.00   60.00
BEAM:    15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00
AGGR:                                                                                                                               

ELEM:       Ba      La      Ce      Pr      Cr      Nd      Mn      Fe      Ni      Zn      Ca      Te      Cs       O       H      Li   SUM
   129    .571    .556    .679    .256    .315   1.597    .239   2.065    .316   1.946   2.669    .168    .908  48.591    .000  39.124 100.000
   130    .687    .752    .615    .357    .293   1.543    .219   2.019    .329   2.045   2.603    .168    .917  48.453    .000  39.000 100.000
   131    .538    .598    .808    .431    .313   1.706    .271   2.089    .337   1.997   2.618    .156    .909  48.375    .000  38.853 100.000
   132    .508    .578    .935    .346    .287   1.550    .238   2.062    .318   1.939   2.645    .166    .919  48.491    .000  39.017 100.000
   133    .696    .759    .603    .275    .331   1.747    .248   2.148    .341   2.093   2.627    .151    .920  48.303    .000  38.756 100.000
   134    .545    .726    .654    .271    .341   1.827    .242   2.089    .323   1.992   2.607    .163    .904  48.411    .000  38.903 100.000
   135    .480    .654    .635    .393    .313   1.664    .235   2.070    .315   2.041   2.610    .162    .918  48.496    .000  39.015 100.000
   136    .532    .611    .796    .385    .285   1.829    .232   2.058    .332   1.922   2.588    .163    .904  48.415    .000  38.946 100.000
   137    .535    .832    .756    .293    .342   1.694    .223   2.108    .326   1.897   2.625    .155    .918  48.400    .000  38.896 100.000
   138    .495    .851    .685    .357    .346   1.705    .243   2.049    .326   2.021   2.632    .149    .904  48.376    .000  38.860 100.000

AVER:     .559    .692    .717    .336    .317   1.686    .239   2.076    .326   1.989   2.623    .160    .912  48.431    .000  38.937 100.000
SDEV:     .075    .107    .105    .059    .023    .101    .014    .035    .009    .063    .023    .007    .007    .080    .000    .106    .000
SERR:     .024    .034    .033    .019    .007    .032    .005    .011    .003    .020    .007    .002    .002    .025    .000    .033
%RSD:    13.34   15.44   14.72   17.68    7.28    6.01    6.01    1.71    2.66    3.14     .87    4.38     .75     .17     .00     .27
STDS:      542     457     458     459     124     460      21     315     315      87      41     160      94       0       0       0

STKF:    .5347   .5322   .5285   .5427   .2925   .5473   .2770   .3168   .3365   .4846   .3194   .7728   .2593   .0000   .0000   .0000
STCT:    753.7   852.7  1138.6  1390.6  2588.5  1395.9  2698.1  3702.3  5150.6  7250.3 63999.2 57600.3 22181.0      .0      .0      .0

UNKF:    .0048   .0060   .0062   .0029   .0029   .0143   .0021   .0185   .0030   .0168   .0264   .0014   .0080   .0000   .0000   .0000
UNCT:      6.8     9.6    13.3     7.4    25.5    36.4    20.5   216.4    45.2   251.0  5285.8   105.8   687.4      .0      .0      .0
UNBG:      3.2     3.4     4.8     4.7     6.5     4.4     7.3     9.2    16.3    26.5   138.4   146.8   212.6      .0      .0      .0

ZCOR:   1.1579  1.1595  1.1639  1.1696  1.1002  1.1826  1.1379  1.1206  1.1055  1.1859   .9943  1.1277  1.1355   .0000   .0000   .0000
KRAW:    .0090   .0112   .0116   .0053   .0098   .0261   .0076   .0585   .0088   .0346   .0826   .0018   .0310   .0000   .0000   .0000
PKBG:     3.24    3.94    3.85    2.64    4.95    9.39    3.84   24.74    3.78   10.49   39.22    1.72    4.23     .00     .00     .00
INT%:     ----   -5.53   -2.53  -14.01    -.32    -.09    ----    ----    ----    ----     .00   -2.44    -.79    ----    ----    ----

TDI%:    7.866    ----    ----    ----    ----  -1.910    ----    ----    ----    ----    .022    ----    ----    ----    ----    ----
DEV%:      6.9    ----    ----    ----    ----     2.3    ----    ----    ----    ----      .1    ----    ----    ----    ----    ----
TDIF:  LOG-LIN    ----    ----    ----    ---- LOG-LIN    ----    ----    ----    ---- LOG-LIN    ----    ----    ----    ----    ----
TDIT:    47.40    ----    ----    ----    ----   48.40    ----    ----    ----    ----   54.20    ----    ----    ----    ----    ----
TDII:     10.1    ----    ----    ----    ----    40.5    ----    ----    ----    ----   5426.    ----    ----    ----    ----    ----
TDIL:     2.31    ----    ----    ----    ----    3.70    ----    ----    ----    ----    8.60    ----    ----    ----    ----    ----


Then the second one like this:

Un    5 SON68_10kV, Results in Elemental Weight Percents
 
ELEM:       Na      Al      Si       B      Mg      Sr       Y       P      Zr      Mo       O       H      Li
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    CALC    SPEC    DIFF
BGDS:      EXP     EXP     LIN     EXP     EXP     LIN     LIN     LIN     LIN     LIN
TIME:    15.00   15.00   15.00  200.00  150.00   40.00   20.00   40.00   20.00   40.00
BEAM:    15.04   15.04   15.04   15.04   15.04   15.04   15.04   15.04   15.04   15.04
AGGR:                                                                                                       

ELEM:       Na      Al      Si       B      Mg      Sr       Y       P      Zr      Mo       O       H      Li   SUM
   144   6.842   2.423  21.155   4.656    .001    .324    .186    .115   2.061   1.195  51.526    .000   9.517 100.000
   145   6.948   2.450  21.233   4.609    .007    .315    .175    .124   2.022   1.256  51.463    .000   9.399 100.000
   146   6.925   2.524  20.990   4.697    .005    .299    .157    .123   1.941   1.248  51.555    .000   9.536 100.000
   147   6.815   2.493  21.064   4.538    .003    .291    .130    .130   2.109   1.266  51.469    .000   9.694 100.000
   148   7.018   2.503  20.931   4.699    .005    .319    .094    .123   2.094   1.231  51.489    .000   9.494 100.000
   149   7.058   2.464  21.138   4.684    .003    .281    .164    .125   1.958   1.220  51.513    .000   9.390 100.000
   150   6.908   2.487  20.987   4.723    .003    .243    .105    .128   1.998   1.210  51.616    .000   9.592 100.000
   151   6.802   2.396  20.882   4.474    .003    .338    .140    .118   1.995   1.262  51.472    .000  10.117 100.000
   152   6.757   2.397  21.040   4.513    .005    .293    .097    .116   2.071   1.224  51.528    .000   9.959 100.000
   153   6.953   2.472  21.107   4.630   -.002    .329    .077    .119   2.005   1.236  51.517    .000   9.557 100.000

AVER:    6.903   2.461  21.053   4.622    .003    .303    .132    .122   2.025   1.235  51.515    .000   9.625 100.000
SDEV:     .097    .044    .108    .087    .003    .028    .038    .005    .057    .023    .047    .000    .237    .000
SERR:     .031    .014    .034    .027    .001    .009    .012    .002    .018    .007    .015    .000    .075
%RSD:     1.41    1.79     .51    1.88   76.32    9.21   28.55    4.09    2.79    1.89     .09     .00    2.47
STDS:      281     261     281     281     232     151     439     439      88     280       0       0       0

STKF:    .0640   .0828   .2341   .0066   .0938   .4257   .4321   .1692   .4147   .0090   .0000   .0000   .0000
STCT:   1474.0  3324.4  9472.6   165.7  3124.8  2747.9  2986.8  3775.3  3178.5    91.1      .0      .0      .0

UNKF:    .0493   .0210   .1899   .0062   .0000   .0024   .0010   .0010   .0152   .0093   .0000   .0000   .0000
UNCT:   1135.5   841.4  7684.5   155.8      .9    15.5     6.8    22.8   116.3    93.9      .0      .0      .0
UNBG:     12.9    34.0    48.8    22.2    19.8     7.2     6.4     7.1     6.8    11.1      .0      .0      .0

ZCOR:   1.3994  1.1737  1.1084  7.4651  1.2519  1.2667  1.3509  1.1945  1.3342  1.3254   .0000   .0000   .0000
KRAW:    .7703   .2531   .8112   .9401   .0003   .0056   .0023   .0060   .0366  1.0309   .0000   .0000   .0000
PKBG:    90.41   25.80  159.02    8.03    1.05    3.19    2.10    4.21   18.31    9.49     .00     .00     .00
INT%:     ----    ----    ----    ----    ----    ----    ----    ----    -.02    ----    ----    ----    ----

TDI%:     .846    ----    ----  -1.926    ----   1.600    ----    ----    ----    ----    ----    ----    ----
DEV%:       .3    ----    ----      .3    ----     3.1    ----    ----    ----    ----    ----    ----    ----
TDIF:  LOG-LIN    ----    ---- LOG-LIN    ---- LOG-LIN    ----    ----    ----    ----    ----    ----    ----
TDIT:    30.20    ----    ----  213.20    ----   55.80    ----    ----    ----    ----    ----    ----    ----
TDII:    1149.    ----    ----    177.    ----    22.6    ----    ----    ----    ----    ----    ----    ----
TDIL:     7.05    ----    ----    5.18    ----    3.12    ----    ----    ----    ----    ----    ----    ----


What you need to do to combine the normal intensity data and the TDI data is to select both samples and click the Combine the Selected Samples into a New Sample button as seen here:



When the samples are combined you will see a new sample which now has the TDI data from both selected samples referenced by the new sample
as seen here:



Now when you click the normal Analyze button for the newly created sample, the output will look like this:

Un    7 (Un    3  SON68_20kV, Un    5  SON68_10kV), Results in Elemental Weight Percents
 
ELEM:       Ba      La      Ce      Pr      Cr      Nd      Mn      Fe      Ni      Zn      Ca      Te      Cs      Na      Al      Si       B      Mg      Sr       Y       P      Zr      Mo       O       H      Li
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    CALC    SPEC    DIFF
BGDS:      LIN     LIN    S-Lo     LIN     LIN     LIN     LIN     LIN     LIN     LIN     EXP     LIN     EXP     EXP     EXP     LIN     EXP     EXP     LIN     LIN     LIN     LIN     LIN
TIME:    30.00   30.00   30.00   30.00   30.00   30.00   40.00   20.00   40.00   20.00   40.00   60.00   60.00   15.00   15.00   15.00  200.00  150.00   40.00   20.00   40.00   20.00   40.00
BEAM:    15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.00   15.04   15.04   15.04   15.04   15.04   15.04   15.04   15.04   15.04   15.04
AGGR:                                                                                                                                                                                                               

ELEM:       Ba      La      Ce      Pr      Cr      Nd      Mn      Fe      Ni      Zn      Ca      Te      Cs      Na      Al      Si       B      Mg      Sr       Y       P      Zr      Mo       O       H      Li   SUM
   155    .601    .581    .707    .265    .326   1.651    .244   2.101    .320   1.944   2.921    .183    .962   7.321   2.502  21.436   4.468    .001    .327    .186    .115   2.057   1.184  46.078    .000   1.518 100.000
   156    .723    .786    .641    .369    .303   1.595    .224   2.054    .333   2.044   2.851    .182    .972   7.446   2.532  21.523   4.416    .007    .318    .175    .124   2.018   1.244  45.862    .000   1.256 100.000
   157    .567    .625    .841    .446    .323   1.763    .277   2.126    .341   1.996   2.866    .170    .963   7.432   2.611  21.287   4.498    .005    .302    .157    .122   1.938   1.236  45.869    .000   1.237 100.000
   158    .535    .604    .974    .358    .297   1.602    .242   2.097    .321   1.937   2.895    .181    .973   7.301   2.576  21.352   4.347    .003    .295    .130    .130   2.105   1.254  45.912    .000   1.576 100.000
   159    .733    .794    .628    .284    .342   1.806    .253   2.186    .344   2.092   2.876    .164    .975   7.537   2.590  21.229   4.498    .005    .323    .094    .123   2.091   1.219  45.724    .000   1.089 100.000
   160    .574    .759    .682    .280    .353   1.889    .247   2.126    .327   1.992   2.854    .178    .958   7.568   2.548  21.433   4.487    .004    .285    .165    .125   1.955   1.208  45.863    .000   1.140 100.000
   161    .506    .683    .662    .406    .323   1.721    .239   2.107    .319   2.041   2.856    .176    .972   7.403   2.571  21.277   4.531    .003    .246    .105    .128   1.995   1.199  46.064    .000   1.467 100.000
   162    .560    .638    .828    .399    .295   1.890    .237   2.093    .336   1.920   2.831    .177    .957   7.294   2.478  21.175   4.282    .003    .342    .140    .118   1.992   1.250  45.839    .000   1.926 100.000
   163    .564    .870    .787    .303    .354   1.751    .228   2.144    .329   1.896   2.872    .168    .971   7.245   2.478  21.330   4.314    .005    .296    .097    .116   2.067   1.212  45.874    .000   1.727 100.000
   164    .522    .890    .713    .369    .358   1.762    .248   2.085    .330   2.020   2.882    .162    .958   7.460   2.557  21.403   4.432   -.002    .333    .078    .119   2.002   1.224  45.832    .000   1.265 100.000

AVER:     .589    .723    .746    .348    .327   1.743    .244   2.112    .330   1.988   2.870    .174    .966   7.401   2.544  21.345   4.427    .004    .307    .133    .122   2.022   1.223  45.892    .000   1.420 100.000
SDEV:     .079    .112    .110    .062    .024    .105    .015    .036    .009    .063    .025    .008    .007    .108    .046    .106    .086    .003    .028    .038    .005    .056    .023    .106    .000    .271    .000
SERR:     .025    .035    .035    .019    .008    .033    .005    .011    .003    .020    .008    .002    .002    .034    .015    .034    .027    .001    .009    .012    .002    .018    .007    .034    .000    .086
%RSD:    13.35   15.45   14.71   17.71    7.29    6.00    6.02    1.71    2.65    3.15     .88    4.38     .75    1.46    1.82     .50    1.95   76.34    9.21   28.54    4.09    2.79    1.88     .23     .00   19.06
STDS:      542     457     458     459     124     460      21     315     315      87      41     160      94     281     261     281     281     232     151     439     439      88     280       0       0       0

STKF:    .5347   .5316   .5280   .5422   .2922   .5467   .2766   .3168   .3365   .4843   .3190   .7728   .2588   .0642   .0830   .2346   .0066   .0941   .4272   .4328   .1695   .4154   .0091   .0000   .0000   .0000
STCT:    753.7   852.7  1138.6  1390.6  2588.5  1395.9  2698.1  3702.3  5150.6  7250.3 63999.2 57600.3 22181.0  1474.0  3324.4  9472.6   165.7  3124.8  2747.9  2986.8  3775.3  3178.5    91.1      .0      .0      .0

UNKF:    .0048   .0060   .0061   .0029   .0029   .0142   .0021   .0185   .0030   .0168   .0263   .0014   .0080   .0494   .0210   .1903   .0062   .0000   .0024   .0010   .0010   .0152   .0093   .0000   .0000   .0000
UNCT:      6.8     9.6    13.3     7.4    25.5    36.4    20.5   216.4    45.2   251.0  5285.8   105.8   687.3  1135.5   841.4  7684.5   155.8      .9    15.5     6.8    22.8   116.3    93.9      .0      .0      .0
UNBG:      3.2     3.4     4.8     4.7     6.5     4.4     7.3     9.2    16.3    26.5   138.4   146.8   212.6    12.9    34.0    48.8    22.2    19.8     7.2     6.4     7.1     6.8    11.1      .0      .0      .0

ZCOR:   1.2194  1.2141  1.2137  1.2133  1.1386  1.2237  1.1629  1.1402  1.1180  1.1858  1.0896  1.2260  1.2048  1.4974  1.2109  1.1216  7.1547  1.3132  1.2769  1.3527  1.1921  1.3298  1.3104   .0000   .0000   .0000
KRAW:    .0090   .0112   .0116   .0053   .0098   .0261   .0076   .0585   .0088   .0346   .0826   .0018   .0310   .7703   .2531   .8112   .9401   .0003   .0056   .0023   .0060   .0366  1.0309   .0000   .0000   .0000
PKBG:     3.24    3.93    3.84    2.64    4.95    9.39    3.84   24.74    3.78   10.49   39.22    1.72    4.23   90.41   25.80  159.02    8.03    1.05    3.19    2.10    4.21   18.31    9.49     .00     .00     .00
INT%:     ----   -5.60   -2.56  -14.14    -.32    -.10    ----    ----    ----    ----     .00   -2.41    -.80    ----    ----    ----    ----    ----    ----    ----    ----    -.02    ----    ----    ----    ----

TDI%:    7.866    ----    ----    ----    ----  -1.910    ----    ----    ----    ----    .022    ----    ----    .846    ----    ----  -1.926    ----   1.600    ----    ----    ----    ----    ----    ----    ----
DEV%:      6.9    ----    ----    ----    ----     2.3    ----    ----    ----    ----      .1    ----    ----      .3    ----    ----      .3    ----     3.1    ----    ----    ----    ----    ----    ----    ----
TDIF:  LOG-LIN    ----    ----    ----    ---- LOG-LIN    ----    ----    ----    ---- LOG-LIN    ----    ---- LOG-LIN    ----    ---- LOG-LIN    ---- LOG-LIN    ----    ----    ----    ----    ----    ----    ----
TDIT:    47.40    ----    ----    ----    ----   48.40    ----    ----    ----    ----   54.20    ----    ----   30.20    ----    ----  213.20    ----   55.80    ----    ----    ----    ----    ----    ----    ----
TDII:     10.1    ----    ----    ----    ----    40.5    ----    ----    ----    ----   5426.    ----    ----   1149.    ----    ----    177.    ----    22.6    ----    ----    ----    ----    ----    ----    ----
TDIL:     2.31    ----    ----    ----    ----    3.70    ----    ----    ----    ----    8.60    ----    ----    7.05    ----    ----    5.18    ----    3.12    ----    ----    ----    ----    ----    ----    ----

[Probeman]

Bumping this topic forward in case some of you missed this cool new absorbed current acquisition capability in the TDI feature...

http://probesoftware.com/smf/index.php?topic=11.msg2499;topicseen#msg2499

[Anette von der Handt]

Ok, I have been playing with the "Assigned TDI" function and ran into some problems. I would like to double check that I am not blind or am missing an important point when it comes to the Assigned TDI function (although I am thinking it is more that the "Assigned TDI" is the red-headed step child to the "Self TDI" and it hasn't come up yet).

1. I can only see "Self TDI" but not "Assigned TDI" data under "Run" -> "Display Time Dependent (TDI)...."

2. I can only see the TDI data for the first batch of elements under "Standard Assignments" - Elements - Use TDI Assigned Calibration Correction, even though it acquired data for all elements.

3. I also cannot assign then the TDI calibration correction to the second (third, fourth..) batch of elements to a sample acquired by "normal acquisition" even though I have data for all of them (see above).

Thoughts? Thanks!

[John Donovan]

Ok, I have been playing with the "Assigned TDI" function and ran into some problems. I would like to double check that I am not blind or am missing an important point when it comes to the Assigned TDI function (although I am thinking it is more that the "Assigned TDI" is the red-headed step child to the "Self TDI" and it hasn't come up yet).

1. I can only see "Self TDI" but not "Assigned TDI" data under "Run" -> "Display Time Dependent (TDI)...."

2. I can only see the TDI data for the first batch of elements under "Standard Assignments" - Elements - Use TDI Assigned Calibration Correction, even though it acquired data for all elements.

3. I also cannot assign then the TDI calibration correction to the second (third, fourth..) batch of elements to a sample acquired by "normal acquisition" even though I have data for all of them (see above).

Thoughts? Thanks!

Hi Anette,
First- don't use the assigned TDI feature.        But seriously, I'm curious why you are using the assigned TDI feature because it's difficult for me to imagine a situation in which the assigned TDI would be more useful than the self TDI. Certainly the self TDI is more accurate and easier to use!  The only time I can think of where the assigned TDI might be useful is when one wants to be sure that the line to line compositional variation in a sample is not due to the self TDI statistics...

Second- it's not meant to be used how I suspect you are trying to use it.  For example, to see the assigned TDI data, just use the Raw Data button in the Analyze! window for the sample that is the TDI assigned calibration curve. Each data point/line in the assigned TDI sample is one TDI calibration point.

Third- call me and let's chat about it.  I almost never use this feature and haven't in a long time so it might not be functioning exactly correctly.
john

Edit by John: I fixed the disabled control for assigned TDI samples with subsequently acquired elements on each spectrometer (order > 1), that you described above. Ready to download now.

[John Donovan]

In addition, I should mention that the assigned TDI is also useful when you need to perform a TDI correction on an element that is *not* acquired as the first element on a spectrometer.  Since the self TDI can only be performed on the first element on a spectrometer...

[gmorgan@ou.edu]

I hope this is the right place...

In the recent (2016) MAS abstracts from Madison, I noticed an abstract by Stephen Kuehn on using TDI along with combined WDS-EDXA methods to analyze glasses using a reduced beam diameter.
I've tried something similar to this (but using a broad beam) to simplify methods (single beam condition) for complex F-bearing, borosilicate rhyolitic glasses, doing Al and Si by EDXA, but hit a snag. At "Analyze" the software tells me that there is no TDI data available for the elements done by EDXA. So, how can both WDS and EDXA data be acquired simultaneously while enabling TDI correction? Is there a way to turn off the TDI feature only for the EDXA elements, or does it work if the total EDXA count time is less than the first increment of TDI for the WDS? Doing things consecutively (e.g., EDXA followed by WDS) won't work for hydrous things because a large fraction of alkali migration (10-30% for simple rhyolitic compositions saturated in H2O at 2 kbar) occurs during the first 1-3 seconds of irradiation. 

[Probeman]

I hope this is the right place...

In the recent (2016) MAS abstracts from Madison, I noticed an abstract by Stephen Kuehn on using TDI along with combined WDS-EDXA methods to analyze glasses using a reduced beam diameter.
I've tried something similar to this (but using a broad beam) to simplify methods (single beam condition) for complex F-bearing, borosilicate rhyolitic glasses, doing Al and Si by EDXA, but hit a snag. At "Analyze" the software tells me that there is no TDI data available for the elements done by EDXA. So, how can both WDS and EDXA data be acquired simultaneously while enabling TDI correction? Is there a way to turn off the TDI feature only for the EDXA elements, or does it work if the total EDXA count time is less than the first increment of TDI for the WDS? Doing things consecutively (e.g., EDXA followed by WDS) won't work for hydrous things because a large fraction of alkali migration (10-30% for simple rhyolitic compositions saturated in H2O at 2 kbar) occurs during the first 1-3 seconds of irradiation.

Hi George,
There is no TDI correction for EDS elements at this time.  Basically one would have to acquire individual EDS spectra for each "self" TDI interval.   I'm sure "John" will get around to implementing this at some point!

Interestingly, this might already work using the "assigned" TDI method that Anette mentions above since each data point (data line) with the "assigned" TDI method is actually a TDI point.  And since each data point in PFE gets its own EDS spectra...

Try the assigned TDI with EDS elements and let us know what you find out...

[JohnF]

John

Tell me that I am wrong, but as best I can figure it out, you output to the LOG WINDOW _ONLY_ TDI corrected counts when an actual quant analysis is performed.

We are using TDI to evaluate optimal 'minimal beam impact on hydrous sheet silicates with FE electron probe' with different beam sizes AS WELL as impact of acquiring scanned (BSE) images, looking only at raw count (P+B) vs time date.

We were applying various curves and seeing NO change in the RAW DATA output (we are NOT setting up standards, as this is an experiment on a given reference material and we don't need to acquire a standard), regardless of whether we turn TDI on or off, or change the curvature.

We see the Y intercept is shown, which provides the value we need.

But it can be confusing, if someone is only acquiring raw counts. You might want to add a comment in the TDI plot windows that RAW DATA shown in LOG WINDOW is only the TDI-uncorrected data.

If this is incorrect, please explain.

Thanks.

[Probeman]

But it can be confusing, if someone is only acquiring raw counts. You might want to add a comment in the TDI plot windows that RAW DATA shown in LOG WINDOW is only the TDI-uncorrected data.

Hi John,
That is correct.  Raw data is raw data (and always will be, per omnia secula seculorum). The TDI correction is applied during the matrix correction, along with the background correction, interference correction and all other corrections.
john

[Probeman]

I recently discussed the new TDI scanning method on the NIST SRM K-1718 beam sensitive material here:

http://probesoftware.com/smf/index.php?topic=912.msg5904#msg5904

However, the point analyses of this material are also worth looking at. This material has the following composition as specified by NIST:

ELEM:       Na      Fe      Ca      Si       O   SUM
ELWT:   14.837  10.491   3.574  28.048  43.050 100.000
OXWT:   20.000  13.497   5.000  60.005   1.498 100.000
ATWT:   13.994   4.073   1.933  21.655  58.344 100.000

Here are TDI plots of log intensities for Na and Si, first with a 20 nA focused beam:





I had to utilize the double exponential fit to get even a halfway decent composition as seen here:

15 keV, 20 nA, 0 um, 1 sec intervals:

ELEM:       Na      Fe      Ca      Si       O   SUM
   172  14.331  11.200   4.035  29.551  43.476 102.593
   173  12.957  11.087   4.337  29.952  43.542 101.874
   174  12.794  11.243   3.993  29.676  43.079 100.785
   175  16.627  11.606   4.224  30.640  45.706 108.802

AVER:   14.177  11.284   4.147  29.955  43.951 103.513
SDEV:    1.773    .224    .161    .486   1.188   3.603

TDI%:  928.684  -6.004    .202 -13.391     ---
DEV%:      3.6      .6     1.0      .2     ---

The averages aren't all that bad considering the Na extrapolation is over 900% (!), and the Si extrapolation is over 13 % (negative).

And here again, but with a 20 nA, 20 um defocused beam:





Again, all plotted in log intensity space. I find it interesting that with a 20 um beam, the Na trend, instead of the normal exponential, hyper-exponential or double exponential trends, we instead see a "hypo-exponential" trend.  That is, a little less than a normal exponential... and here are the quant results:

15 keV, 20 nA, 20 um, 1 sec intervals:

ELEM:       Na      Fe      Ca      Si       O   SUM
   208  14.643  10.321   3.802  28.711  42.282  99.758
   209  14.711  10.788   3.838  29.091  42.887 101.315
   210  15.123  10.710   3.728  28.991  42.851 101.404
   211  13.979  10.394   3.872  28.746  42.140  99.130

AVER:   14.614  10.553   3.810  28.885  42.540 100.402
SDEV:     .474    .230    .061    .186    .385   1.136

TDI%:   53.503  -3.738  -2.765  -4.833     ---
DEV%:       .4      .7     1.3      .2     ---

The defocused beam analyses are, not surprisingly, quite a bit better and the TDI corrections much more reasonable for this very *unreasonable* material!.   
john

[Ben Buse]

Hi,

I have a controversial suggestion - to see what you think. Currently TDI only applies to first row elements. This restricts it to the first element on each of the spectromters. I'd like to suggest that it could be used for second row elements - if it was done carefully checking that the intensity was a linear drop of with time - then it can be done for the second row elements. A case were it might be useful is volcanic glass with 2 TAP, 2 PET, and 2 LIF. Where Al is measured after Si (i.e. can't measure Si, Al and Na in first row). Currently you have to make sure its stable for the second row Al, so having to make sure Al is linear drop off is not much harder?

Ben

[John Donovan]

Hi,

I have a controversial suggestion - to see what you think. Currently TDI only applies to first row elements. This restricts it to the first element on each of the spectromters. I'd like to suggest that it could be used for second row elements - if it was done carefully checking that the intensity was a linear drop of with time - then it can be done for the second row elements. A case were it might be useful is volcanic glass with 2 TAP, 2 PET, and 2 LIF. Where Al is measured after Si (i.e. can't measure Si, Al and Na in first row). Currently you have to make sure its stable for the second row Al, so having to make sure Al is linear drop off is not much harder?

Ben

Hi Ben,
The only reason I don't allow using TDI on subsequent pass elements (those elements other than the first element on each spectrometer), is simply because I suspect it will simply not be accurate enough when extrapolating that far to zero time.

One way to test whether we can make this far an extrapolation, would be to set a long "incubation" interval in the Acquisition Options dialog, say 40 secs or so, thus exposing the sample to the beam for 40 secs before the TDI measurement starts. Then we can see how accurate these extrapolations are.

The problem is, I'm sure that one can find situations where this long extrapolation will work, when utilizing gentle enough conditions. But there will also be beam/sample conditions that will yield an inaccurate extrapolation.

The problem is, unlike the first element in the spectrometer pass, if there is no data for the first 40 secs or so, how will one know that the extrapolation is inaccurate?

I'm willing to discuss it, but as you say, it is "controversial"!
john

[Probeman]

Since beam sensitive samples are being discussed in the Cs standard topic by Brian Joy and I just had a student run some very beam sensitive rhyolite glasses earlier this week, I thought we might revisit the the Time Dependent Intensity (TDI) correction feature since the student got some excellent results in a very hydrous alkali glass that entailed some very large corrections.

This was apparently a Bishop Tuff rhyolite pumice which they suspected from FTIR analysis would have around 5 wt% H2O. So we tuned up the instrument for 15 keV, 15 nA and used a 5 um beam (for the Mg, Ca, Cl, Ti and F traces we used a 50 nA beam). Normally we would use a more defocussed 10 um beam to keep the TDI correction a little more reasonable, but the glass bubble walls were very thin, and as they say "necessity is a mother".   

Here is the last sample she ran, and note the average correction percent and average variation percent (in red):

Un   55 unknown 147_16, Results in Elemental Weight Percents
 
ELEM:       Na      Si       K      Al      Fe      Mg      Ca      Cl      Ti       F       O       H       P      Mn       S
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    CALC    DIFF    SPEC    SPEC    SPEC
BGDS:      MAN     MAN     LIN     MAN     MAN     MAN     MAN     LIN     LIN     LIN
TIME:    40.00   40.00   40.00   40.00   40.00  165.00  150.00  120.00  120.00  120.00     ---     ---     ---     ---     ---
BEAM:    14.91   14.91   14.91   14.91   14.91   50.73   50.73   50.73   50.73   50.73     ---     ---     ---     ---     ---

ELEM:       Na      Si       K      Al      Fe      Mg      Ca      Cl      Ti       F       O       H       P      Mn       S   SUM 
   188   3.108  34.107   3.788   6.193    .460    .018    .294    .096    .021    .041  51.273    .601    .000    .000    .000 100.000
   189   3.378  33.632   3.838   6.347    .486    .018    .290    .092    .026    .044  51.218    .631    .000    .000    .000 100.000
   190   3.415  33.822   3.634   6.267    .585    .017    .289    .085    .033    .061  51.185    .608    .000    .000    .000 100.000

AVER:    3.300  33.854   3.753   6.269    .510    .018    .291    .091    .027    .049  51.225    .614    .000    .000    .000 100.000
SDEV:     .168    .239    .106    .077    .066    .000    .003    .005    .006    .010    .045    .015    .000    .000    .000    .000
SERR:     .097    .138    .061    .045    .038    .000    .002    .003    .004    .006    .026    .009    .000    .000    .000
%RSD:     5.08     .71    2.83    1.23   12.94    2.16     .92    6.01   23.15   21.19     .09    2.52     .00     .00     .00
STDS:      336     162     374     336     162     162     162     285      22     835     ---     ---     ---     ---     ---

STKF:    .0735   .2018   .1132   .1332   .0950   .0568   .1027   .0602   .5547   .1715     ---     ---     ---     ---     ---
STCT:    64.51  244.54  138.78  220.67   20.49   70.15  188.59   61.70   42.06   23.55     ---     ---     ---     ---     ---

UNKF:    .0179   .2768   .0324   .0488   .0042   .0001   .0026   .0007   .0002   .0001     ---     ---     ---     ---     ---
UNCT:    15.72  335.41   39.70   80.80     .91     .15    4.75     .74     .02     .02     ---     ---     ---     ---     ---
UNBG:      .33     .31     .94     .85     .20     .48     .93     .33     .05     .05     ---     ---     ---     ---     ---

ZCOR:   1.8421  1.2230  1.1593  1.2854  1.2090  1.4697  1.1257  1.2548  1.2064  4.1458     ---     ---     ---     ---     ---
KRAW:    .2437  1.3716   .2860   .3662   .0444   .0021   .0252   .0120   .0004   .0007     ---     ---     ---     ---     ---
PKBG:    48.89 1068.36   43.46   96.38    5.47    1.31    6.13    3.26    1.38    1.35     ---     ---     ---     ---     ---
INT%:     ----    ----    ----    ----    ----    ----    ----    ----    ----    -.86     ---     ---     ---     ---     ---

TDI%:  282.195  -2.408  35.459  -2.496   5.719    ----    ----    ----    ----    ----     ---     ---     ---     ---     ---
DEV%:      5.4      .2      .9      .4  1895.2    ----    ----    ----    ----    ----     ---     ---     ---     ---     ---
TDIF:  HYP-EXP LOG-LIN LOG-LIN LOG-LIN LOG-LIN    ----    ----    ----    ----    ----     ---     ---     ---     ---     ---
TDIT:   101.33  102.00  103.67  104.67  104.33    ----    ----    ----    ----    ----     ---     ---     ---     ---     ---
TDII:     12.3    335.    40.5    81.5    1.11    ----    ----    ----    ----    ----     ---     ---     ---     ---     ---
TDIL:     2.51    5.81    3.70    4.40    .106    ----    ----    ----    ----    ----     ---     ---     ---     ---     ---

Un   55 unknown 147_16, Results in Oxide Weight Percents

ELEM:     Na2O    SiO2     K2O   Al2O3     FeO     MgO     CaO      Cl    TiO2       F       O     H2O    P2O5     MnO     SO3   SUM 
   188   4.189  72.966   4.563  11.702    .592    .030    .412    .096    .035    .041    .000   5.375    .000    .000    .000 100.000
   189   4.554  71.952   4.623  11.993    .625    .029    .406    .092    .043    .044    .000   5.639    .000    .000    .000 100.000
   190   4.603  72.357   4.377  11.841    .752    .029    .404    .085    .056    .061    .000   5.436    .000    .000    .000 100.000

AVER:    4.449  72.425   4.521  11.845    .656    .029    .407    .091    .044    .049    .000   5.483    .000    .000    .000 100.000
SDEV:     .226    .511    .128    .146    .085    .001    .004    .005    .010    .010    .000    .138    .000    .000    .000    .000
SERR:     .131    .295    .074    .084    .049    .000    .002    .003    .006    .006    .000    .080    .000    .000    .000
%RSD:     5.08     .71    2.83    1.23   12.94    2.16     .92    6.01   23.15   21.19     .00    2.52     .00     .00     .00
STDS:      336     162     374     336     162     162     162     285      22     835     ---     ---     ---     ---     ---

Note that the H2O by difference is close to 5% which was very nice to see. However, that is in spite of the Na TDI correction is almost 300%, which means that we lost 2/3 of our intensity during the count integration!  The TDI plot for Na looks like this:



We could probably get a little better accuracy by using a slightly shorter integration time.  Here also is the plot for K which was a 35% correction:



and this for Si and Al:





and both are statistically significant corrections if you will compare the TDI%: and DEV%: values for Si and Al.  However, for an element such as Fe, there is no TDI effect, as seen in both the TDI%: and DEV%: values and also from the plot here:



So if you are analyzing hydrous alkali glasses (even with a defocused beam) I hope you are turning on the TDI correction feature!

[AndrewLocock]

Hello,
We run a lot of hydrous rhyolitic glass, and this has encouraged me to look at zeolites in more detail.
However, I noticed that the time-scale for the self-TDI is a bit funny.
Our initial setup is 20 s on peak, with 5 TDI intervals, so the spacing should be every 4 seconds (right?).

A JPG of the screen capture of the TDI data is attached.
The text from the associated DAT file follows:

"Elapsed Time (10 keV, 10 nA,5 um, 4 sec)"   "Na ka Intensity (cps/1nA)"
 3.00000    118.593
 10.0000    113.562
 16.0000    114.460
 23.0000    107.661
 30.0000    102.197

It is not clear to me why the intervals are not an even 4 seconds apart....
Thanks,
Andrew