The main application file is called DTSA and has an ICON which
is intended to look like a multi-channel analyzer.
The program is started in the usual Macintosh way by rapidly double
clicking on this ICON.
DTSA makes and uses a number of files on your disk. To make intelligent
use of them and the program, descriptions of the files follow.
Contents of Chapter.
The main application file is called DTSA and has an ICON which
is intended to look like a multi-channel analyzer.
The program is started in the usual Macintosh way by rapidly double
clicking on this ICON.
All of the X-ray and other physical data are in a file called
XRayData.
The spelling of the name is important, as is the location of this
file. It must be in the same folder as DTSA and at the same "level"
as DTSA; i.e., it must not be inside another folder in the DTSA
folder. The file is in a binary format and cannot be read by a
word processor or a text editor.
Preferences MCA is a binary file of all the variables, settings,
color schemes etc., used the last time the program was run. DTSA
"makes" a file with this name every time you quit the
program, overwriting the previous version. This file is read by
the program when it starts so that you are exactly where you were
when you quit. One of the menu items, DTSA Setups, discussed later,
allows you to name other "DTSA Set-up" files that may
each be written for some purpose such as saving the settings for
a particular electron column instrument. When instructed to read
this file DTSA reconfigures for this other purpose. CAUTION, if
you have inadvertently gotten into trouble by attempting to learn
about a function by guessing, it is possible that some internal
damage to variables will occur. If you quit DTSA after such a
knowledge quest, then all of the damage will be remembered for
your next use of the program. In such a case it is advisable to
throw the Preferences.MCA file in the trash and start over. Do
not use an old Preferences MCA file with version 2.5 of DTSA as
it will crash.
Files that have the icon DTSA REFS are sets of reference distributions
(references) used in the linear-least-squares (MLLSQ) curve fitting
procedure.
A stored reference ideally extends over an energy region just
big enough to encompass one x-ray family. The background in this
region must have been removed from the source spectrum before
the reference was obtained. Background Subtract for procedures to
accomplish background subtraction and MLLSQ References for more information about saving and manipulating references.
A common error is to confuse "references" with "standards".
References are peak profiles, or shapes, which represent the detector
response to a family of x-ray lines. They are used in the MLLSQ
fitting procedure to determine the area of an x-ray family. Standards
are obtained from specimens with known compositions. It is the
ratio of the family area from the "unknown" to that
of a "standard" that permits the conversion of the fitted
area into the concentration of an element.
Files that have the icon DTSA FIT result from curve fitting one
or more spectra.
Both the SIMPLEX and the MLLSQ procedures create such binary files.
If you do not supply a name for the file, a default name is assigned.
The particular name will depend on which curve fitting procedure
you are using and whether you are fitting spectra "one at
a time" or are "batch processing" a large number
of spectra. The FIT file contains a complete record of the experimental
conditions and fitting information for each spectrum. This binary
file is used by DTSA to create "Spreadsheets" for Excel©,
Kaleidagraph© and Statview©. Any other spreadsheet program
that supports TAB delimiting will be able to read these ASCII
files. A Microsoft Word© TEXT document of the fit file information
can also be created. Since the file is of type "TEXT"
it can be opened by any word processor. The text file and spread
sheets can be written as soon as the fit file is completed or
any time later. New York font at size 9 is recommended for the
display and printing conditions.
Files that have the icon DTSA MLLSQ SET-UP contain all of the information
needed to rapidly set-up a particular MLLSQ fitting operation.
An MLLSQ Set-up file can be written anytime after a set of fitting
data is accepted from the MLLSQ Set-up dialog. There are similar
Set-up Files for Simplex fitting and for quantitative analysis.
Files that have the icon CL K's are files of k-factors for the
Cliff-Lorimer quantitation method.
They are created and may be examined using the Cliff-Lorimer menu
item under the Analysis Menu.
Files that have the icon DTSA HALL SET-UP contain all of the information
needed to rapidly set-up a particular Hall quantitation.
A Hall Set-up file can be written from the Hall Set-up dialog
or an old Set-up file may be called from the same dialog.
Files that have the icon DTSA HALL OUTPUT contain all of the results
of a Hall quantitation.
A Hall Output file is written at the conclusion of a Hall quantitation.
Files that have this icon contain standards data for ZAF quantitative analysis. Both the ZAF procedure and the CITZAF procedures make and use the same standards files; therefore, once standards have been made by either procedure, they may be used by either procedure for a quantitative analysis. These standards should NOT be confused with the reference files used by the MLLSQ procedure - those are peak shape references only and are NOT ZAF standards.
Particular set-ups for ZAF analyses may be saved after doing a ZAF set-up and have this icon.
This file has no default name. Files that have this icon may be
created by the user to save compositions of often used standards
These files are created or accessed from the Spectrum Header Window,
The Background Subtract Window or the Generate Windows. This file
is not associated with any spectrum. It contains only composition,
valences and density of standard materials as entered by the user
and the descriptive Headers.
Files with this icon are used to save sets of peak labels so they
may be recalled later.
Files that have this icon with the name "SpectralEngine"
interface DTSA with the 4pi, Inc. spectral engine board if installed.
Files that have these icons are used to import or export spectrum
data files of different formats. Place the ones you need in the
"Plug-ins" folder inside the folder with DTSA. Store
the others in another folder. When DTSA is started, the file reading
plug-ins (blue) are loaded into the Import File Menu and the file
writing plug-ins (green) are loaded into the Export File Menu.
Selecting one from the Menu will allow you to read or write a
file of that format.
Since these are separate from the main DTSA program, new plug-ins
may be written and added at any time without the necessity of
creating a new DTSA program. It is only necessary to put the new
plug-in into the "plug-ins" folder to make it available
for use.
Files that have the icon "DTSA File" are the files
in which spectrum histograms and descriptive information are stored.
A DTSA File is essentially a laboratory notebook of spectrum
data. A DTSA File can contain one or as many spectra as you have
room for on your disk. In the context of the DTSA, a spectrum
is more than the histogram of counts versus energy increment.
This histogram has very little meaning unless we know the experimental
conditions for acquisition. This experimental information is stored
in the DTSA File in structures of data called headers; the headers
are inseparable from the histograms they describe. DTSA uses two
types of headers: the first is an "Experiment Header"
which is written only once at the beginning of each DTSA file
of spectra. This header contains information that is common to
all the spectra in the file, such as the beam energy, detector
take-off angle, analysts etc., Each spectrum histogram that follows
has its own header, called a "Spectrum Header". This
header contains information that may change from spectrum to spectrum,
such as the beam current, the x, y coordinates, etc. DTSA makes
it very easy to enter the information, which then cannot be "misplaced"
as so often happens with the laboratory notebook, and to "read"
or edit the header information.
A DTSA file of spectra is illustrated graphically, in the
following figure:
See the Appendix for the DTSA File Pascal structures. The header structures list the data that are stored and are informative even if you are not familiar with the Pascal language.
Files that have the icon "QC Setup" are the files that are
created by the Quality Control module when defining a quality control procedure.
This is the file that is run each time a quality control spectrum has been selected.
It only contains the procedure that you define. All the data is saved in a
spreadsheet.
Others
There are some other files that may be generated by DTSA but at this time do not have special icons. These may be assigned later in an update.