FISCHER FISCHERSCOPE X-RAY 5000 Series, Руководство оператора

Страница: 47 / 188

Base material in Def.MA Product Administration
FISCHERSCOPE
®
X-RAY 47
7.14 Base material in Def.MA
Definition of the base
material
Def.MA files may be created

either by FISCHER, from where they may be forwarded to the user
for example as email attachment - the user may copy them to
WinFTM using the menus
"Product -> Copy to/from file... -> file >>> DefMA" - or by e-mail,

or by the customer himself using the software module
WinFTM SUPER (menus "Calibrate-> DefMA new").
A Def.MA file contains parameters used to create an application by
calibration as well as a prescription according to the definition of
the specific structure (i.e. measuring mode) of the sample. This
enables
WinFTM to evaluate the measured spectrum in order to get a set of
variables characterizing the sample. It is most important for the
accuracy of the measured values that the Def.MA is defined in an
accurate and meaningful manner. Unfortunately the user can fail
during this procedure in many aspects by providing false entries.
Therefore correct inputs in the dialogue window "definition of
measuring conditions and application (Def.MA)" have mostly to be
based on a solid and thorough knowledge of the physics of X-ray
fluorescence.
While defining the structure of the sample - top coating,
intermediate coating, base material - the user has multiple choices
to characterize base material:

consisting of one element

composition predefined

multiple element composition

composition unknown
With the exception of the last choice the composition of the base
material fluorescence will be respected by WinFTM the same way
as the fluorescence of the several coating layers during evaluation
of the spectrum. By the first three structural definitions, the
elements which the base material consists of have to be known to
the algorithm and therefore have to be specified explicitly. From
this, after normalization the exact composition of the base material
is known to WinFTM even quantitatively (calculated by standard
free method) and can be realized by looking to the content of
Def.MA in the application window. All possible secondary effects of
the fluorescence energy coming from the substrate and penetrating
the layer(s) are recognized and taken into account by WinFTM in a
correct manner (examples: Cr on Fe, Au/Ag).
Any mistake during normalization or measuring, e.g. false base
material with respect to the definition (for example Fe instead of Cu)
instantaneously leads to the warning "spectrum not applicable".