Maintenance
SORVALL
®
Centrifuges
5-4
4. Press START. Using a stopwatch, begin timing precisely as
the RUN TIME display counts down to 13:20; then stop
timing precisely as the RUN TIME display counts down to
00:00.
The stopwatch should read between 13:15 to 13:25, representing
13:20 ±0.5% (4 seconds) plus an additional second to allow for
cumulative human error. If necessary, repeat this procedure at
other time ranges that are commonly used in your protocols.
Temperature Controls
When verifying temperature control, all test run conditions
(TEMP, SPEED, TIME, ROTOR and option selections) should
match your required protocol(s). Before the run, it is important
for the test fluid to be at the same volume and temperature as the
actual sample, and for the SET temperature, the displayed RUN
Temperature, and the temperature of all parts of the rotor
assembly to match also (ideally, all rotor components would have
been stored in the same controlled-temperature area overnight,
but if that is not possible, you can precool or preheat the rotor as
required).
1. Choosing a commonly used protocol with the longest run
time, set the centrifuge run parameters.
2. Equilibrate the rotor chamber and the temperature of all
rotor parts (include any tubes, bottles, or adapters to be used)
to the desired sample temperature.
3. Make sure the rotor chamber is wiped dry, then install the
rotor in the chamber and keep the chamber door closed until
you load the rotor.
4. Prepare two equal loads of test fluid (similar in volume to
normal run samples) equilibrated to the desired sample
temperature – check the sample temperature using a cali-
brated thermometer (such as a Fluke 51 K/J or equivalent).
NOTE Test fluid must be compatible with aluminum and
have a freezing point below the desired sample
temperature.
5. Load and balance the rotor according to the instructions in
the rotor manual, then close the chamber door.
6. Press START – during the run, the RUN display tempera-
ture should be within 2° of the SET display temperature.
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