FISCHER FISCHERSCOPE X-RAY 4000 Series, Operator'S Manual

Page: 14 / 170

14 FISCHERSCOPE
®
X-RAY
Instrument Overview Functional Principle of the Instrument
4. A light source (not shown in Fig. 2-2) illuminates the sample. A mirror and lens direct
the image of the measurement location to a color video camera. The mirror has a hole
in its center for the primary radiation to pass through.
5. The aperture (collimator) limits the cross-section of the primary beam in order to excite
a measurement spot of a defined size.
6. The primary x-radiation impacts the atoms on the sample surface (coating layer and
base material) and in the process knocks electrons from the inner electron shell.
Electrons from outer electron shells fill the resultant voids emitting a fluorescence
radiation that is characteristic in its energy distribution for a particular material.
7. The energy dispersive detector measures the energy distribution of the fluorescence
radiation. A multistage electronics circuit processes the measurement signals.
8. The measured spectrum shows lines or peaks that are characteristic for the chemical
elements in the sample.
9. The WinFTM Software computes the thickness of the coating(s) and/or the analysis
result. The video image of the sample is shown in the WinFTM window. The precise
position of the measurement location and the measurement spot is possible due to the
special design of the optical and the x-ray guidance systems.