How to change Combined conditions order AND use EDS

[David Steele]

I attach a snapshot of the Acquisition Options window which informs me I can't change the acquisition order when using Combined conditions, AND EDS is not available when using Combined Conditions.  OK I accept the latter (which I was not aware off, before attempting to use it!) BUT am not happy with the first....

My analytical problem, which I'm sure is not an unusual one, is the analysis of (low) carbon steels.  My analytical setup is C at 7kV, the rest at 15kV (Si, Cr, Mn, Fe, P, Al, Ni and Mo, but I'd like to add more in the future...)

My problem is that although I have the anticontamination 'trap' working on the 8530F, the spot is still leaving a visible contamination mark by the end of the analysis.  Just to complicate matters, and the subject of this posting, is that even though C was selected as the first element in Elements/Cations when I first defined the element list this morning, PfE is analysing the 15kV elements first then doing C last which is the last thing I really want given that (obviously) the surface contamination and thence the measured C abundance will be increasing as the acquisition proceeds

Hence my desire to analyse C at 7kV first and do the rest at 15kV.

How (where) can I convince PfE to do this sequence???



The second 'issue' is that I would like to do Fe by EDS in the above samples, to a) reduce the acquisition time but b) to avoid deadtime issues having to count near-100wt% Fe on an LiFH crystal at 20nA!  It seems rather a waste of hardware to have the EDS being unable to 'do' anything if Combined conditions are used.  OK I appreciate the potential complexities of PfE having to handle two or more ED spectra acquired at different kV and matrix correct the intensities.

OK one option might be to opt for using another (third) Condition e.g. C at 7kV20nA; Fe at 15kV, 5nA; the rest at 15kV, 50nA, BUT I'm trying to shorten the acquisition time AND make more efficient use of the hardware available.

Do any other PfE options/capabilities spring to more PfE-experienced minds?

Many thanks

David (SteelE)
QUT 

[John Donovan]

I attach a snapshot of the Acquisition Options window which informs me I can't change the acquisition order when using Combined conditions, AND EDS is not available when using Combined Conditions.  OK I accept the latter (which I was not aware off, before attempting to use it!) BUT am not happy with the first....

Do any other PfE options/capabilities spring to more PfE-experienced minds?

David,
No worries (as they say).

OK, I will "fall on my sword" for this one (honor demands it)! But only because my colleague Julie Chouinard just last week asked me the same darn question!

Yes, I agree the dialog only says this:



And yes, I will admit that it *does not* say "using combined conditions".

So yes, I will change the wording. But the point is, you can change the acquisition order for samples using "combined conditions", that is, multiple keVs, nanoamps, or beam sizes (or entire column condition files!), using the Combined Conditions button in the Acquire! window as seen here:



Sorry about that, I will fix the wording of the dialog this weekend, if not sooner. 

As for the using EDS *during* the "combined conditions" acquisition, I'm sure you can detect the "rub". I will have to calculate the appropriate time at which the acquisition changes conditions, and terminate the EDS acquisition before that... but that will involve several other issues, such as quant... so let me think about it.  I usually find that if I "ruminant" a while on the issue, the solution eventually comes to me much more easily than if I try to "force it"!
john

PS I guess I could use the "pause" function in the EDS-WDS integration API (both Bruker and Thermo support a "pause" function). As long as the KeV condition does not change!

[John Donovan]

I attach a snapshot of the Acquisition Options window which informs me I can't change the acquisition order when using Combined conditions, AND EDS is not available when using Combined Conditions.  OK I accept the latter (which I was not aware off, before attempting to use it!) BUT am not happy with the first....

Hi David,
Here is the new version acquisition order dialog that I modified to make it clearer about using the Combined Conditions button in Acquire! to modify the acquisition order for "combined conditions" samples.



john