Du Pont SORVALL RC-5 Service Manual page 190

Son/all®
CentrifugesCalibration
ProceduresWHITE
WIRESNOS403&411REMOVED
FROMTB
3067/79RCS/111Figure
7-2. Test Setup/or
Temperature Meter Deflection
Adjustmentk.
Rotor Speed Temperature
Differential Set-Point
Calibration
at20
000
Rpm
(R41)This
procedure compensates
for the
temperature
differential between the rotor and
thechamber
at
20 000
rpm.1.
Install an
SS-34
rotor
with
two tubes
balanced and
half full of alcohol or other
anti-freezing
liquid prechilled to
+2°C.2.
Set the
RUN
mode set-pointer to
-3°C.3.
Operate in the
RUN
mode at
5000
rpm
until the temperature indication
stabilizes
at-3°C,
and then at
20 000
rpm
for
45
minutes.
With the brake
on,
allow
the rotor
todecelerate
to
a complete stop. Then,
record
the
temperature.4.
At
zero
rpm,
quickly place a
thermometer into one
tube for three minutes,
thenquickly
into the second
tube for two
minutes.
The desired temperature
of the
mate¬rial
in the rotor is
+2°C
with the pointer set
at
-3°C.5.
Adjust potentiometer
R41 until the
-3°C
set-pointer
indication is
5°C
colder
thanthe
temperature
recorded in
step
4 —
clockwise
rotation will increase
the
rotor
tem¬perature
while
moving
the temperature pointer
downward
.Rev.
5/937-7