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SECTION 5
OPERATING PRINCIPLES
5.1. PREPARATION OF THE ROTOR TO RUN
Before installation, check the rotor for corrosion and cleanliness.
Chemical corrosion or mechanical corrosion may do severe damage to the rotor and the
centrifuge. Particles which are stuck inside the inserts cause the breakage of tubes and lead to
major imbalance please check to make sure that no particles are left on the rotor.
The central hole of the rotor and the motor shaft should also be clean and dry before all
centrifugal operations and they must be kept in that way all the time.
5.2. LOADING
The most important condition of an efficient centrifugation is to balance the tubes properly. Loading
must be done by meeting the requisites of static and dynamic balance.
Static Balance:
This balance states that diametrically oppositely replaced weights are almost the
same. In application, the liquid level in the tubes should be at the same height to balance the load.
Dynamic Balance:
This balance states that diametrically oppositely replaced center of the gravity
of tubes are symmetrical with respect to spinning axis of the rotor.
Although in hospitals the samples having almost the same densities are centrifuged, in
industry, samples having different densities may be centrifuged. In this case, the dynamic
balance becomes more important factor than the static balance is.
If the number of tubes to be centrifuged is less than the capacity of the rotor, the tubes must be
placed oppositely. If an odd number of tubes is centrifuged, a water filled tube at the same
weight should be used for balancing.
Imbalance of the rotor may cause major damage to the rotor and centrifuge.
Never attempt to introduce liquids into the tube inserts.
Balance the rotor with glass tubes if you use glass tubes for centrifugation.
Balance the rotor with plastic tubes if you use plastic tubes for centrifugation.
Always use tubes which can withstand to the set speeds.
Examples of the proper and improper loading are shown below.
