Specifications

PN SJ-IM-8AC
1-3
Description
Centrifuge Chassis
1
Imbalance Detector
An imbalance detector monitors the rotor during the run, causing automatic shutdown if rotor
loads are severely out of balance. At low speeds, an incorrectly loaded rotor can cause an imbalance.
Rotor instability can also occur if the instrument is moved, or if it is not resting level on the floor
(see CHAPTER 3, Troubleshooting).
Overspeed and Rotor Identification System
A rotor identification system prevents the installed rotor from running above its maximum rated
speed. During acceleration the microprocessor checks the magnetic rotor identification. If the
system identifies a rotor different than the one entered by the user, and the set speed is above the
maximum for the identified rotor, the system will reduce the set speed to the maximum for the
installed rotor.
A second check, based on rotor physical properties, is performed during acceleration. Speed is
limited to the maximum safe speed of the identified rotor group.
NOTE
Some rotors manufactured before January, 2002, may not have magnets installed. Based on the rotor
property grouping, these rotors may be limited to a lower speed than the rated speed.
Centrifuge Chassis
Housing and Door
The instrument housing is made of steel and molded structural foam. The door and structural-foam
cover panels are finished with polyurethane enamel.
The steel and structural foam door is hinged at the back, providing clearance for loading and
unloading of the centrifuge. In the event of a power failure, the door can be manually unlocked for
sample recovery (see CHAPTER 3, Troubleshooting).
Rotor Chamber
The rotor chamber is made of stainless steel to resist corrosion. A rubber gasket around the
chamber opening ensures sealing. (Instrument gaskets have not been qualified as bioseals for
aerosol containment.)
Vacuum
The friction reduction system (FRS) uses a mechanical rotary vane vacuum pump to reduce
chamber pressure to approximately one-half atmosphere. The pump turns on when the run is
started, before rotor friction reaches a high level. Vacuum in the chamber is vented automatically
during rotor deceleration.