Laboratory centrifuge Sigma 2-7, Sigma 2-7 Cyto
Laboratory centrifuge Sigma 2-7 IVD
8 Maintenance and service
Version 07/2015, Rev. 1.12 of 16/07/2019
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Translation of the original operating manual, part no. 0702802
8.1.3
Rotors, buckets and carriers
Rotors, buckets and carriers are produced with the highest precision, in
order to withstand the permanent high stress from high gravitational fields.
Chemical reactions as well as stress-corrosion (combination of oscillating
pressure and chemical reaction) can affect or destroy the metals. Barely
detectable cracks on the surface can expand and weaken the material
without any visible signs.
• Check the material regularly (at least once a month) for
– cracks
– visible damage of the surface
– pressure marks
– signs of corrosion
– other changes.
• Check the bores of the rotors and multiple carriers.
• Replace any damaged components immediately for your own safety.
• After every cleaning process, grease the rotor tie-down screw slightly
with a small amount of heavy-duty grease for load-bearing bolts (part
no. 71401) and distribute the grease with a cloth so that it forms a thin
layer.
8.1.4
Glass breakage
CAUTION
In the case of glass breakage, immediately remove all glass particles (e.g.
with a vacuum cleaner). Replace the rubber cushions since even thorough
cleaning will not remove all glass particles.
Glass particles will damage the surface coating (e.g. anodising) of the
buckets, which will then lead to corrosion.
Glass particles in the rubber cushions of the buckets will cause glass
breakage again.
Glass particles on the pivot bearing of the load- bearing bolts prevent the
buckets and carriers from swinging evenly, which will cause an imbalance.
Glass particles in the rotor chamber will cause metal abrasion due to the
strong air circulation. This metal dust will not only pollute the rotor chamber,
rotor, and materials to be centrifuged but also damage the surfaces of the
accessories, rotors, and rotor chamber.
In order to completely remove the glass particles and metal dust from
the rotor chamber:
• Grease the upper third of the rotor chamber with e.g. Vaseline.
• Then, let the rotor rotate for a few minutes at a moderate speed
(approx. 2000 rpm). The glass and metal particles will now collect at the
greased part.
• Remove the grease with the glass and metal particles with a cloth.
• If necessary, repeat this procedure.
