EXIT
– Used to exit from a menu. When EXIT is pressed, any changes
made to the displayed value are ignored.
5)
The control indicator is a two color light emitting diode (LED). This in-
dicator lets the user visually see the ratio of heating to cooling. When the
indicator is red the heater is on, and when it is green the heater is off and
the bath is cooling.
7.2
Bath Tank and Lid
The bath tank and lid assembly includes: the tank, the control probe, the stir-
ring motor and cover, 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 inside the stir motor cover so that the probe tip
is fully immersed in the bath fluid.
•
The stirring motor is mounted on the bath tank lid. It drives the stirring
propeller to provide mixing of the bath fluid. Proper mixing of the fluid is
important for good constant temperature stability. A motor cover encloses
the motor and probe area. A fan draws air through the cover to cool the
motor.
•
On the bath lid is a large access hole. This is used for filling and emptying
the bath with fluids and placement of thermometers and devices into the
bath.
•
An access hole cover should be used to cover the access opening in the
top of the bath at all times. This improves bath temperature stability, pre-
vents excess fluid evaporation or fumes, and increases safety with hot
fluid. The user may drill or cut holes in the cover to accommodate the in-
struments to be calibrated or immersed in the bath. Spare covers are avail-
able from Hart Scientific.
•
A stainless steel baffle inside the tank insures proper fluid flow. It also
protects probes and thermometers from coming in contact with the stir-
rers. There are slots near the bottom of the baffle for insertion of the liq-
uid-in-glass adaptor.
7.3
Back Panel
On the back of the bath there are two systems fuses, the power cord, drain, se-
rial port, IEEE-488 port (if installed), and the fluid expansion reservoir.
6331 Calibration Bath
User’s Guide
24
