This part of the instrument (optical microscope) is used to explore the area of the sample
(dimensions 25.000µ x 25.000µ (limit of the micropositioning)) in the X-Y directions
and to decide where to fix the volume (5µ x 5µ x 5µ) to map.

With the possibility to rotate the telecamera, we can make also an exploration in Z,
so we have the possibility to make an almost stereoscopic exploration (very important for our type of analyses).

The exploration is necessary to identfy the exact location of the volume (a cube of 5µ x 5µ x 5µ )
which will then be scanned in three dimensions with the AFM.

Once we have identified (with the exploration phase) the volume to examine, 5µ x 5µ x 10µ,
and once we see it clearly and steady on the screen,
we now must approach the PCa Probe-Carrier to the sample.

X-Y-Z approach:
X-axis: there is no need to move it, because it is always centered on the focal axis
(maybe only small focalisation movements).
Y-axis: used to enter inside the field of view
Z-axis: used to focalise the tip of the probe and to approach the tip to the sample

This operation must be done with a tollerance of 1µ
in order to bring the tip to the point (0-0-2) which was found in the exploration phase
(This point (0-0-2) is already in focus).

At this point the microapproaching phase is finished and the nanoapproaching phase starts.