8
CORNING DIGITAL HOT PLATES, STIRRING HOT PLATES, STIRRERS
AND EXTERNAL TEMPERATURE CONTROLLER
7.0 Heating Operation
7.1 Principles
The heating element and a temperature sensor are located just beneath the ceramic top
surface of the product. The microprocessor-controlled heat, generated by the heating
element, is based upon the sensor temperature and the value set on the Heating
Temperature Display. When the sensor temperature is not within range of the value set on
the display, the display will
FLASH
. When the sensor temperature is within range, the value
displayed will remain constantly
ON
.
The Heating Temperature Display does not indicate the actual temperature of materials
placed on top of the product or the actual temperature of the ceramic top surface.
The following table shows a typical difference between the temperature set on the Heating
Temperature Display and the actual temperature measurement of the ceramic top surface.
Temp. Set on
Display (°C)
Actual
Top Surface
Temp. (°C)
50
45
100
85
150
125
200
165
250
205
300
245
(This information was taken using a 6795-420D with no top load in 20°C ambient conditions).
Using the External Temperature Controller (Cat. No. 6795PR) enables precision temperature control
of materials placed in vessels on top of the product.
When the External Temperature Controller is connected to the product, the closed loop
control process is extended to include temperature input from the External Temperature
Controller. The microprocessor-controlled heat, generated by the heating element, is based
upon the sensor temperature located in the tip of the External Temperature Controller
and the value set on the Heating Temperature Display. When the sensor temperature is
not within range of the value set on the display, the display will
FLASH
. When the sensor
temperature is within range, the value displayed will remain constantly
ON
.
To directly control the temperature of liquid in a vessel on the top surface, place the External
Temperature Controller into the liquid and connect the Controller to the product. The
Heating Temperature Display shows the temperature of the liquid and can be used to adjust
the temperature of the liquid. See Section 10.0 for ordering information.
CAUTION:
The top surface and the vessel used may be at substantially higher
temperatures than indicated by the setting on the Heating Temperature Display
as the controller regulates the liquid temperature inside the vessel.
7.2 Safety
The microprocessor-controlled system has built-in error routines to detect product operation
in some unfavorable conditions. The type of error routines which may be active in a product
varies depending upon the functionality of the model and the operating software version.
Temp. Set on
Display (°C)
Actual
Top Surface
Temp. (°C)
350
285
400
325
450
365
500
405
550
440
