Sorvall RT/T6000D - Page 153

RT6000
and
T6000
Centrifuges
SORVALL®
Centrifuges
e.
Temperature
Control
P.C.
Board (PN
07530)
Adjustments41
Temperature
Meter
Adjustment
1.
With POWER
switch
set
to
OFF, turn temperature meter adjusting screw
on
the
face
of
the
meter
(using
a
screwdriver)
until
meter reads
-20°C
(see
figure
7-5).
Temperature Sensor
Coincidence Adjustment
1.
Set the
POWER
switch
to
ON, and
open
the
centrifuge lid.
Remove
the
rotor
(if
necessary).
Carefully loosen
the
temperature sensor
located
on
the bottom of the
rotor
chamber
(to
the
right
of the
gyro
assembly).
2.
Remove
the
door release
knob
by
loosening
the
set
screw.
3.
Remove
the
screw
(located
above
the
TIME
control
knob)
that
secures
the
front
panel
to the
frame.
Gently lower
front
panel.
4.
Prepare a
warm
water beaker.
28°C
to
32°C
(SOT
to
90°F).
Leaving
the
thermom¬
eter
in
the
beaker,
immerse
the
temperature
sensor.
With the
POWER
switch set
to
ON.
read
the
temperature
meter and
adjust
Rl 1
on
Temperature
Control
P.C.
Board.
The
temperature
meter and
sensor must
agree
±1°C.
5.
Prepare
an ice water
bath
and
immerse
the
temperature
sensor.
Read the
temperature
meter and adjust
R7
on
the
Temperature
Control
P.C.
Board.
The
temperature meter
and
sensor must
agree
±1'C.
6.
Repeat steps
4
and 5 until
no
further
adjustment
is
required.
Temperature
Control Knob Coincidence
Adjustment
1.
Set
the
POWER
switch to
OFF.
and
unplug
the
centrifuge
power cord.
2.
Connect test leads
from
a
digital
voltmeter
to
pin
1
and
pin
7
of
Zl
on
the
Temperature
Control
P. C.
Board. Measure
the
dc
voltage
at
both the
warm
and
cold
temperatures
(see
above)
and
record.
3.
Remove test
lead from
pin
7 of Zl
and
connect
this lead
to
the
wiper (center
terminal)
of the
temperature potentiometer
(located
on
front
panel).
4.
Adjust
the TEMP
control knob to
the
same
temperature
used
in
step
4
of
the
Temperature Sensor
Coincidence
Adjustment
procedure
(warm water beaker).
Adjust
R3
on
the
Temperature
Control
P.C.
Board
to read
the
same measured
voltage
that
was
recorded in
Step
2
of this
procedure.
5.
Adjust
the
TEMP
control knob
to
the
same temperature
used in
step
5
of
the
Temperature Sensor
Coincidence
Adjustment
procedure
(ice
water bath). Adjust
R2
on
the
Temperature
Control
P.C.
Board to
read
the
same measured voltage
that
was
recorded in
Step
2 of
this
procedure.
If
the
Temperature
Control
P.C.
Board
has been
upgraded
to
PN
07841,
see
Section
8
of this
manual (or
the calibration
procedure.
7-24