23
CANNON
®
CT-1000 Constant Temperature Bath
Revision 3.1a—February, 1998;
CANNON
®
Instrument Company
P.O . Box 16 • State College, PA • USA
D
APPENDIX D
—
ADJUSTING
TRIMPOTS (POTENTIOMETERS)
The ten trimpots located immediately behind the front control panel can
be accessed by pulling the drawer forward a few inches. An opening in
the drawer cover allows direct
access without the necessity of
removing the cover. The
trimpots are adjusted with a
small screwdriver (see
Figure
15
).
There is one trimpot corre-
sponding to each of the set
temperatures on the dial.
These are normally set so that
the
Temperature Adjust
FIXED
dial will be at the
midpoint (500 on the ten-turn
dial) of range when at the
control temperature. Setting
the
Temperature Adjust FIXED
dial at the midpoint ensures maximum
adjustment in either direction to establish the desired temperature if
additional adjustment is necessary.
If a temperature other than one that is available on the
Temperature
SELECT
switch is to be accessed frequently, it may be possible to obtain
this temperature by adjusting the trimpot that coincides with the
Tempera-
ture SELECT
temperature that is close to the desired temperature.
For example, if 100°F is a temperature that is often needed, and 40°C is
not used, set the
Temperature SELECT
switch to 40°C and adjust the
trimpot until the kinematic viscosity thermometer indicates the bath is
controlling at 100°F. It is necessary to note for future reference that the
40°C position on the select dial is now 100°F. In some cases it may also
be necessary to set the
Temperature Adjust FIXED
dial to a position
other than the midpoint in order to obtain the desired temperature.
While the method described above will permit the
Temperature SE-
LECT
setting to be altered, it may not be possible to obtain settings for
temperatures that are widely different from those on the
Temperature
SELECT
dial. In this case, use the
Temperature Adjust VARIABLE
dial to obtain the desired temperature.
Figure 15: Adjusting potentiometers
