Bright Instruments
44
4.1 DAILY CARE
Routine daily care consists of removing
sectioning debris from the working area and
brushing debris & frost from the knife.
4.2 AUTOMATIC DEFROST CYCLE
Refer to section 2.1.11. The function of
the automatic defrost cycle is to clear
the evaporator cooling fins of frost but
without allowing the chamber or microtome
temperature to rise above 0ºC. This ensures
efficient refrigeration.
4.3 TOTAL DEFROSTING
It will be necessary to periodically defrost the
entire cryostat to carry out cleaning and/or
other procedures. The frequency of this total
defrosting will depend on how heavily the
cryostat is used; it may be as often as daily
but is commonly once a month.
To initiate a total defrost:
a. Place a suitable container under the drain
tube.
b. Turn off the cryostat.
IMPORTANT:
If decontamination of the
cryostat is required carry out the standard
procedures as practised in your laboratory
at this point. Refer to section 4.8 for
further details. Anti-roll plate.
c. Remove the microtome knife (refer to
section 2.3.2) and clean it (see section 4.4).
d. Remove the microtome from the chamber,
the reverse of the installation procedure
(see section 1.2.5). Remove drain plug from
base of chamber.
e. Place the microtome on the laboratory
bench and clean it. Refit the rewind knob and
rewind the feed mechanism until the pointer is
at the bottom on the indicator. Undo the two
knurled screws on the specimen arm and lift
off the upper debris screen. Now remove the
two small screws which hold the microtome
cover, using the Allen key provided. The cover
can now be lifted off. Allow the microtome to
warm up completely and dry it off carefully.
f. The chamber interior can now be cleaned
once it has thawed. Replace the drain plug.
g. Once the chamber and microtome have
been cleaned and dried off, apply a little
low temperature oil to the threads of the
knife clamp screws and feed screw, replace
the cover and re-install in the chamber (see
section 1.2.5).
Make sure that the inside of the cryostat
is perfectly dry before switching the
refrigeration on. Use a hair dryer if necessary.
Note that the microtome requires no other
routine maintenance.
4. Care & Maintenance
