4)
The heater mode is a red light emitting diode (LED). This indicator lets
the user visually see the ratio of heating to cooling. When the indicator
is lit the heater is on, and when it is off the heater is off and the bath is
cooling.
5)
The cooling switch turns on the refrigeration for control below 50°C
and rapid cool down.
7.2
Bath Tank and Lid
The bath tank and lid assembly includes: the tank, the control probe, the stir-
ring motor, the access hole, and the access hole cover.
•
The bath tank is constructed of stainless steel. It is very resistant to oxida-
tion in the presence of most chemicals and over a wide range of tempera-
tures.
•
The control probe provides the temperature feedback signal to the con-
troller allowing the controller to maintain a constant temperature. The
control probe is a precision platinum resistance thermometer (PRT). It is
delicate and must be handled carefully. The probe is placed in the small
hole in the top of the bath so that the probe tip is fully immersed in the
bath fluid. It is located underneath the motor cover.
•
The stirring motor is mounted on the bath tank lid under the motor cover.
It drives the stirring propeller to provide mixing of the bath fluid. Proper
mixing of the fluid is important for good constant temperature stability.
•
On the bath lid is a work area access hole. This is used for filling the bath
with fluids and placement of thermometers and devices into the bath.
When possible the access hole should be covered (must be covered to
reach minimum temperatures).
•
An insulated access hole cover is provided and should be used to cover
the access opening in the top of the bath. This improves bath temperature
stability, prevents excess fluid evaporation or fumes and increases safety
with hot fluid. The user may drill or cut holes in the cover to accommo-
date the instruments to be calibrated or immersed in the bath. Spare cov-
ers are available from GE Kaye Instruments. An optional access cover
which provides locations for two reference thermometers and three wells
for units under test is available.
7.3
Back Panel
On the back of the bath are 1) the system fuses, 2) the non-removable power
cord, 3) the drain valve, 4) the RS-232 interface connector, and 5) removable
vent panel.
24
7 Parts and Controls
