Combined conditions analysis

[wrigke]

In setting up a sample analysis that has combined conditions, I noticed something weird.  I typed "new sample" (unknown) and then proceeded to set up a condition wherein oxygen was measured at 20nA and rare earth elements were measured on the same location at 100nA.  To do this, I used the "combined condition" window in Acquire!  The measurement would begin as I expected with oxygen at 20nA, but then when the column switched to 100nA, the filament saturation changed and the beam alignment changed.  Why does this happen and what am I doing wrong?

Karen

[John Donovan]

Hi Karen,
Make sure that in the Combined Conditions dialog you have the Use Analytical Conditions options selected. Otherwise the program will try and load the specified column condition file for each condition. Does that help?
john

[Gseward]

and whilst in the 'Combined Conditions' window, don't forget to 'modify channel (element) order' so that like-conditions are grouped together on a given spectrometer (and temporally across the spectrometers - using 'Count Times' window). I always seem to forget this step, then wonder why my acquisition order has been changed.

Note, that when using 'Combined Conditions'  the acquisition order cannot be changed in the usual  'Acquisition Options' window. 

Gareth

Edit by John: actually yes, you can change the order on a per spectrometer basis in Acquisition Options dialog. What you can't do is force two elements with the same conditions to run at different times. So elements with similar conditions should be "grouped" together using the Combined Conditions "channel order" option. Otherwise the program will try and figure out the acquisition order on its own...

[wrigke]

OK, here's a twist on the combined conditions.
Suppose I have a number of standards that I measure and that I don't use the same condition for each.  Say I use condition 1 for some and condition 2 for the others.  Suppose further that the temperature in my lab is extremely variable so I want to make sure that I use drift correction and use automation to re-measure the standards every 4 hours.  Finally, I use condition 3 on my unknown. 

I set everything up, measure my standards initially using conditions 1 and 2, then I program in 20 hours of measurements on my unknown using automation.  How can I get my unknown spots to measure using condition 3, and my standards to measure every 4 hours for drift correction using condition 1 for some elements and condition 2 for other elements, and do all this with automation?

Karen

[John Donovan]

OK, here's a twist on the combined conditions.
Suppose I have a number of standards that I measure and that I don't use the same condition for each.  Say I use condition 1 for some and condition 2 for the others.  Suppose further that the temperature in my lab is extremely variable so I want to make sure that I use drift correction and use automation to re-measure the standards every 4 hours.  Finally, I use condition 3 on my unknown. 

I set everything up, measure my standards initially using conditions 1 and 2, then I program in 20 hours of measurements on my unknown using automation.  How can I get my unknown spots to measure using condition 3, and my standards to measure every 4 hours for drift correction using condition 1 for some elements and condition 2 for other elements, and do all this with automation?

Hi Karen,
By "conditions" do you mean the operating conditions or the element setup or both?

So maybe I don't understand the question but it seems to me you can simply use the Sample Setups button in the Automate! window and assign a different sample setup to each standard or unknown position. The software will then automatically load that setup for each digitized standard and/or unknown.

Is that what you mean?

[Philipp Poeml]

Hi Karen,

this is great.  I can see that you are working in a similar lab as I do, facing the same troubles of temperature, different conditions, etc. In fact it is a quite special situation. And I have bugged John many times and tried to explain these special needs... Thanks for your patience, John! I am having the same temperature issues, and there is no easy solution to that, in my case they reduce the ventialtion at night by 50% that means the T goes up, and then down again in the morning. And it is impossible to convince "them" to leave the ventilation on... That's how it is.

To your question: I figured with the help of John, that those "sample setups" he mentioned above are the key to our problems. This will make it work. We can go through it in more detail when you come to Karlsruhe...

Cheers
Philipp

[Richard Walshaw]

Hi All

I'm the new guy in town - as such I'm going to be asking pretty basic questions for a while.

Here's my first one:

I want to analyse a block of glasses followed by a block of pyroxenes all in the same "job".

I'll do all my glasses with a gentle beam current and a defocussed beam, then i want to switch conditions as the pyroxenes will take more current and a more focussed beam.  I'll keep my element-spectro assignments the same for both batches but i'd like to push the count times up for the pyroxenes.

Can you walk me through setting up and running the analyses from the very beginning (i'm wary of missing an important check box somewhere). I intend to call back a "general purpose" silicate setup from previous work and then edit it. Its changing beam conditions and count times as i switch from glass to pyroxene that i'm unsure of.

Thanks

Richard

[John Donovan]

Hi Richard,
That is a great question and my answer will please you!   

What you want to do is create two "sample setups". This procedure is documented in the Advanced Topics manual accessible from the Help menu in PFE (but who reads manuals!).

The opening text is:

Sample Setups
Normally, PROBE FOR EPMA uses the sample setup from the last unknown (or standard if
there are no unknown samples) to create the next new sample setup. Sample setups on the other
hand are designed to allow the user to easily recall a previous sample setup within a current run.
This allows the user to create and re-use multiple setups comprised of different groups of
elements within a single run. In the example below, sample setups for pyroxene and olivine will
be created, each with a different set of elements and conditions, that may be recalled at anytime
during the current probe run.

The saving of a sample setup actually saves only a pointer to the sample selected. All of this
sample's acquisition and calculation options, elements/cations, standard assignments, etc will be
utilized when a new sample is created based on this sample setup.

A new PROBE FOR EPMA run is opened in the usual manner. Ten elements and appropriate
standards for pyroxenes are loaded from the SETUP.MDB database and the STANDARD.MDB
database, respectively. Each element is then calibrated and standardized. Count times,
acquisition and calculation options are adjusted to optimize the analyses and output
requirements.



So basically there are three methods for recalling setups:

File Setups load the selected sample setup and all global flags from a previous probe run

Sample Setups load a sample setup from within the currently open run

Element Setups load a single element setup to the current sample

So you'll first load a file setup from another run, modify as necessary and then click the Save Setups button from the Analyze! window to "save" the selected sample as a Sample setup. This sample setup generally should not contain data so you can continue to modify it further if desired.

Then select the sample setup from the Acquire! New Sample button for manual acquisition or assign a selected sample setup to the position sample list in the Automate! window using the Sample Setups button.

Repeat as necessary for each additional sample setup you want to utilize.

There is also a thread that discusses this here:

http://probesoftware.com/smf/index.php?topic=110.msg404#msg404

Let me know if you have further questions.

[Gareth D Hatton]

I have an interesting one here which many people may have done in the past.

We are currently thinking about using the 1411 glass as a round-robin.  I have a piece from before so decided to give it a test drive.  My difficulty has always been with the analysis of boron.  PfE has fortunately helped with the loss of sodium so there are no worries there. 

I was planning to do everything at 20kv but ran into problems with boron detection (as can be expected when you use calzaf).  My question is can I combine 5kv boron with 20kv for the rest?  And, with the combined conditions it would seem that it does each sample as 5kv then 20kv so if I do the standards at the same time it will be yo-yoing from 5 to 20kv, not good for the FEG!  Or am I missing something subtle in the setup?  Can I even do this type of analysis or should I just do lower KeV for everything? 


   Glass 1411
Na2O   10.14
SiO2       58.04
Al2O3   5.68
K2O       2.97
CaO       2.18
TiO2       0.02
Fe2O3  0.05
MgO       0.33
B2O3   10.94
BaO       5
ZnO       3.85
SrO       0.09
   

[Philipp Poeml]

Hi Gareth,

what about programming your points, then doing first everything at 20 kV and then the rest at 5 kV, or vice versa as you prefer? And then combine everything into one analysis? We used to do that in our lab quite often, first, analyze the 25 kV elements, then the 20 kV elements, and then the 15 kV ones. Works great. And PfE lets you combine afterwards all your elements into one analysis line.

Cheers
Ph

[John Donovan]

I was planning to do everything at 20kv but ran into problems with boron detection (as can be expected when you use calzaf).  My question is can I combine 5kv boron with 20kv for the rest?  And, with the combined conditions it would seem that it does each sample as 5kv then 20kv so if I do the standards at the same time it will be yo-yoing from 5 to 20kv, not good for the FEG!  Or am I missing something subtle in the setup?  Can I even do this type of analysis or should I just do lower KeV for everything? 

You can do as Phillipe suggests above (combine the samples post acquisition), *or* you can simply use the combined conditions feature and assign each element the appropriate voltage for acquisition in a single sample. Just remember to run your standards the same way...

[Philipp Poeml]

John, I noticed something with the combined conditions: When I choose the combined conditions for different elements, and I set a value for nA and a column string, it would only save the column string. I need to open the element a second time, set the nA, and then it will remember. Is that right like this?
Cheers
Philipp

[John Donovan]

John, I noticed something with the combined conditions: When I choose the combined conditions for different elements, and I set a value for nA and a column string, it would only save the column string. I need to open the element a second time, set the nA, and then it will remember. Is that right like this?

Yes. Because if you are using column setups the current will be set from the column setup, not from the analytical conditions.

I suppose you are entering the beam current for documentation purposes?  That is a good idea. I modified the regular analytical conditions dialog to remember the analytical conditions for a given column setup and try to anticipate the user, but I didn't implement that yet under combined conditions.
john

[Philipp Poeml]

Well... There is a little box in that window that says: "If you are using column string, don't forget to set the according value in the analytical conditions" or similar. I can send a screen shot tomorrow, probe is running right now. So I thought this was necessary to do.

[John Donovan]

Well... There is a little box in that window that says: "If you are using column string, don't forget to set the according value in the analytical conditions" or similar. I can send a screen shot tomorrow, probe is running right now. So I thought this was necessary to do.

Not necessary, but nice for documentation as I said. Note that for keV, this field entry is absolutely necessary when using column conditions (*.PCC files), since the beam energy value gets used in the quant routines.
john