Polytec TMS-350 TopMap In.Line, Hardware Manual

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2-2
2 Introduction
2.2 Operating Principle
The TMS-350 is based on the principle of the white-light interferometer. In
one interferometer arm the test sample is fixed in position, in the other there
is a reference mirror. The reference mirror is moved with the aid of a piezo. A
camera depicts the test sample. The captured image is superimposed with the
reference mirror. Interference will only occur if the optical path length
difference between the reference mirror and the corresponding points on the
test sample is zero. During this measurement run, depending on the
topography of the test sample, the software finds interferences pixel by pixel.
Once the predefined distance has been traveled, the topographical structure
of the test sample is digitalized. The results can be evaluated on the screen
with the aid of numerous functions in the TMS software. The export function
and the automation interface also allow an evaluation of the topography data
with other applications.
Figure 2.2: Schematic design of the interferometer