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UltraCW™ Automatic Cell Washing System Service Manual
4.2
Testing whether the imbalance value is in the
permissible range
The imbalance microswitch senses whether the rotor is balanced during operation. If the rotor is not
balanced, an imbalance error results. The weight at which the imbalance error occurs is the imbalance
value.
At the factory, the microswitch is positioned to allow an imbalance value that lies between 5 g and 10 g
when the rotor is spinning at 1500 r/min. For example, if the imbalance value were 7 g (the middle of the
range), an imbalance error would result only if one side of the rotor were more than 7 g heavier than the
other. One gram is approximately equal to 1 ml of saline solution.
Continual operation of the cell washer when the imbalance value of greater than or equal to 10 g may
damage the cell washer. An imbalance value of less than or equal to 5 g is overly sensitive to the normal
variations in weight that occur during operation.
For more information and instructions to program and use the cell washer, refer to the Operation Manual.
You will need the following to test whether the imbalance value is in the permissible range:
►
Tubes (enough to fill all available positions on the rotor)
►
Saline solution. One test run requires 15 g (approximately 15 ml)
►
Scale (calibrated and capable of measuring 10 g)
To test whether the imbalance value is in the permissible range
NOTE:
Regulations for your organization may recommend test methods different from
what appear here. Use the appropriate methods for your organization.
1
Add tubes to all the available positions in the rotor. If you are using 10 mm x 75 mm tubes, confirm
that the tube inserts are installed correctly in all the tube holders.
2
Program the Spin (S) program with a spin speed of 1500 r/min and a spin time of 20 seconds.
3
Test whether the imbalance value is below the upper limit of the permissible range.
a
Starting with empty tubes, add a total of 10 g of saline solution to one or more tubes on one side of
the rotor.
b
Install the rotor.
c
Start the Spin program. If the program completes without an imbalance error, then the imbalance
value is too high and must be decreased. For instructions, see Section 4.3, “Adjusting the
imbalance microswitch.”
4
Test whether the imbalance value is above the lower limit of the permissible range.
a
Add a total of 5 g of saline solution to one or more tubes on one side of the rotor.
b
Install the rotor.
c
Start the Spin program. If an imbalance error occurs, then the imbalance value is too low and must
be increased. For instructions, see Section 4.3, “Adjusting the imbalance microswitch.”
