Beckman Coulter SX4400, Instructions For Use Manual

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B01198AB 10
SX4400 Swinging Bucket Rotor
Preparation and Use
3
If removing the rotor yoke, turn the T-handle wrench to the left (counterclockwise) to loosen
the tie-down screw.
•
Lift the yoke straight up and off the drive shaft.
NOTE
Refer to the centrifuge manual for proper installation and removal instructions. Failure to follow
printed instructions may result in damage to the rotor and the centrifuge.
Run Speeds
The centrifugal force at a given radius in a rotor is a function of speed. Comparisons of forces
between different rotors are made by comparing the rotors’ relative centrifugal fields (RCF). When
rotational speed is adjusted so that identical samples are subjected to the same RCF in two different
rotors, the samples are subjected to the same force. If RPM is entered, the RCF at each speed is
automatically calculated by the centrifuge software; if the RCF is entered, the centrifuge calculates
the equivalent revolutions per minute (rpm).
Do not select rotational speeds that exceed 4700 rpm for
refrigerated centrifuges, or 4200 rpm for nonrefrigerated centrifuges.
Speed Derating
The maximum run speed listed in the rotor specifications is for operation when all conditions are
within the standard specifications. Maximum allowable run speed for the rotor must be reduced in
some circumstances.
1.
The rotor can process solutions at the maximum rated speed if the solution density is 1.2 g/mL
or less. When centrifuging solutions of densities greater than 1.2 g/mL, the maximum run
speeds must be reduced according to the following equation to protect the rotor from excessive
stresses due to the added tube load:
2.
When some glass tubes are used, reduce rotor speed to prevent tube breakage. Because the
strength of tubes can vary from lot to lot, and will depend on handling and usage,
Beckman Coulter highly recommends that you pretest these tubes in the appropriate labware
in the SX4400 rotor, using water samples, to determine optimal operating conditions.
NOTE
Scratches (even microscopic ones) significantly weaken glass tubes.
*Use 4200 for nonrefrigerated Allegra X-30
centrifuges
reduced maximum speed = (4700 rpm)*
1.2 g/mL
density of tube contents
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