60
You can delete a threshold whenever you like by
pressing the same key.
The relevant key must be kept pressed down
until the corresponding symbol in the display
field “z status” has switched over. The display
then shows the active function:
“Set
↑
” setting of the upper threshold,
“Del
↑
” deleting of the upper threshold,
“Set
↓
” setting of the lower threshold,
“Del
↓
” deleting of the lower threshold.
If you see the display “Err”! with flashing LED
↓
or
↑
while you are trying to set a threshold, the
position of the threshold is not acceptable.
Examples: lower threshold = upper threshold
lower threshold > upper threshold.
Attention:
When viewing specimens of different thick-
nesses, the upper threshold must be readjusted
every time the specimen is changed (risk of
collision!).
1.5 Coded objective nosepiece
*
The coded objective nosepiece enables several
parameters to be allocated and stored for each
objective position.
These parameters are:
– Stepwidth of the focusing (see section 1.3),
– Objective magnification (see page 64),
– Offset of objective focal plane (“parfocality”),
p. 62
!
The objective magnification and the offset to the
focal plane must be “read in” once (see page 62,
Calibration).
The stepwidth last used at a nosepiece position
is automatically stored.
The setting of the stored stepwidth, the display
of the magnification and the compensation of
the focus offset are done automatically while
the nosepiece is rotated.
If 2 coded, interchangeable nosepieces are
available, these can be labelled “nosepiece A”
and “nosepiece B” by operating a switch. As the
system is capable of storing up to 14 objective
positions, the data allocated to each objective
are automatically called up or displayed every
time. When you screw out an objective and turn
the nosepiece, you can see the switch inside the
nosepiece. This switch has to be switched to the
left for one nosepiece, and to the right for the
other (not illustrated). This can be done with a
thin wooden stick or similar.
