Micromax HM 340 E - Page 45

Rotary Microtome HM 340 E
MICROM International GmbH
Robert-Bosch-Str. 49
D- 69190 Walldorf 386 200 - English
PART 3 THEORY OF OPERATION
3-1 CUTTING MOVEMENT
The manual rotary movement of the handwheel of
the Rotary Microtome HM 340 E is converted into
a vertical movement of the cylinder head which
carries the specimen holder.
Sectioning is carried out by knives or blades,
which must be adjusted and fixed on the knife
carrier.
With the downward movement of the specimen,
sectioning is carried out (cutting movement).
The upward return travel of the specimen is
carried out by turning the handwheel further in
clockwise direction. During this return travel, the
specimen is drawn back to protect knife and
specimen. If desired, the function <retraction> can
be turned off. The selected section thickness is
delivered at the upper reversal point of the return
travel.
The number of the sections made can be shown on
the section counter on the display. After each
downward movement of the specimen holder, the
number on the section counter increases by 1. The
sum of the sections carried out can also be seen on
the display. For this, trimming values and
sectioning values are added up. Section counter
and sum of section thicknesses can be reset to zero
at any time by means of the RESET-button.
Moreover, the remaining travel to the front end
position can also be shown on the display. The
remaining travel, which is still available for
sectioning, is shown in microns. If the specimen
holder is in the back end position, the display
shows 28 000 µm. This number decreases, the
further the specimen holder is moved towards the
front. (See 2-7, indication of cutting processes).
3-2 SPECIMEN COARSE FEED
AND TRIMMING FUNCTION
After changing the specimen or moving the knife
or knife carrier, it is necessary to adjust the
specimen to the knife edge again. This can easily
be done by means of the specimen coarse feed and
the defined trimming values. After the specimen
and the knife are adjusted, further gradual feed for
trimming can be carried out by pressing the button
for trimming, which is available as pulse or
permanent function. If the <pulse function> is
chosen, the specimen holder moves forwards by
the pre-selected trimming value whenever pressing
the button for trimming. If the <permanent
function> is chosen, the feed is carried out in the
upper reversal point at each handwheel rotation.
3-3 OPERATING PANEL
The operating controls of the panel are well
arranged for safe and easy use. The operating
panel can be removed from the instrument at any
time and used as a separate unit.
3-4 SPECIMEN CLAMPING SYSTEM
AND SPECIMEN ORIENTATION
According to the form and size of the specimens,
different specimen clamping systems are available
to carry the specimen.
It is very easy to align the specimen to the knife,
using the orienting adapter.