Labnet Spectrafuge 24D Digital Microcentrifuge - Manual (Page 7)

4
Figure 1. Loading the rotor to achieve balance
3.4 Loading the rotor
Tubes to be loaded should be filled equally by eye. The difference in the weight between
the tubes should not exceed 0.1 gram. Tubes should always be loaded so that there is
equal spacing between all tubes. One or two additional loaded tubes may need to be
added to achieve this. Refer to Figure 1. to see one typical balancing scheme.
3.5 Overloading rotors
The maximum load of the rotor and the maximum speed have been established by the
manufacturer. Do not attempt to exceed these values. The maximum speed of the rotor
has been established for liquids having a homogeneous density of 1.2g/ml or less. In
order to centrifuge liquids with a higher density it is necessary to reduce the speed.
Failure to reduce the speed may result in damage to the rotor and centrifuge. The
revised maximum speed can be calculated with the following formula:
Reduced speed (n
red
) =
ityValue HigherDens
2 . 1
x max speed ( n
max
)
Example:
Where the density of the liquid is 1.7, the new maximum speed would be calculated as
follows:
n
red
=
7 . 1
2 . 1
x 13,300 = 11,174 rpm
4. Operation
ATTENTION: Never attempt to operate the centrifuge with rotors or adapters that show
signs of corrosion or mechanical damage. Never centrifuge strongly corrosive materials that
may damage the rotors, accessories, or bowl of the unit.
4.1 Attaching rotor lid
After the rotor has been properly secured and loaded, attach the rotor lid to the rotor.
Always use the rotor lid for safety and to allow the rotor to reach proper speed. Make
sure that the rotor lid snaps securely into place, by pressing down on center catch.