Leica DM R Serie Mode D'emploi page 59

1.2.2 Stage height adjustment by keystroke
The stage can be moved up and down at a
maximum speed of about 6 mm per second with
the "Up" (44.2) and "Down" (44.3) keys. At first,
the acceleration is deliberately retarded to
allow fine vertical movements by keystroke.
If the upper threshold has been set (see section
1.4), the stage can be repositioned at this setting
with the "Up" key (with an accuracy of ± 1 µm).
A set upper threshold cannot be overridden with
the "Up" key, but this can be done with the
focusing wheel. If the z drive is above the upper
threshold, the stage will be lowered to the upper
threshold when the "Up" key is pressed.
If no thresholds are set, the stage travels to the
mechanical end-switch position.
!
Attention:
Risk of damage, particularly to the condenser,
the objectives and the specimens.
1.3 Stepwidths, Focusing wheel
Fine focusing
he motorized vertical movement of the stage is
not continuous, but by extremely fine repro-
ducible steps. These are chosen, depending on
the objective, so that the stepwidth is smaller
than the depth of focus, giving the effect of
continuous focusing. The stepwidth for the
focusing wheel can be set with the "Stepwidth"
key (44.1). This alternates between three
possible settings when the key is pressed and is
indicated in the display (44.7). Each objective
position can be individually stored on the coded
objective nosepiece, see page 60.
The three possible stepwidth settings for the
fine focusing are:
1 = 0.1 µm 2 = 0.7 µm
Coarse focusing
By simultaneously pressing the "Up" and
"Down" keys (44.2 and 44.3) you can switch from
the set stepwidth to the "coarse drive of the
focusing wheel" function. When the coarse
drive is activated, numbers 1 – 3 on the left-hand
side of the display light up simultaneously.
With the coarse drive the stage can be moved
up or down by about 1 mm per rotation of the
focusing wheel.
The keystroke function of repositioning at set
thresholds is retained with full accuracy for the
coarse drive.
You can switch back to fine focusing by pressing
keys (44.2 and 44.3) simultaneously again.
1.4 Setting/deleting z thresholds
A threshold can be set at the current stage
position by pressing and sustaining (≥ 1 sec) the
"Upper threshold" (44.5) or "Lower threshold"
(44.6) keys.
3 = 1.5 µm
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