8 Controller Operation
This section discusses in detail how to operate the furnace temperature control-
leru sing the front controlpanel. By using the front panel key-switchesand
LED display theuser may monitor the welltemperature, adjust the set-point
temperaturein degrees C or F, monitor the heater output power, adjust the con-
trollerproportional band, and program the probe calibration parameters, operat-
ing parameters, serial interface configuration, and controller calibration
parameters. Operationof the functions and parameters are shown in the
flowchartin Figure 4 on page 22. This chart may be copied for reference.
In the following discussion a button with the word SET,UP, DOWN, or EXIT
inside indicates the panel button while the dotted box indicates the display
reading. Explanation of the buttonor display reading are to the right of each
button or display value.

8.1 Well Temperature

The digitalLED display on the front panel allows direct viewing of the actual
well temperature. This temperature value is what is normally shown on the dis-
play.The units, C or F, of the temperature value are displayed at the right. For
example,
962.3 C Well temperature in degrees Celsius
The temperaturedisplayed function may be accessed from any other function
by pressing the “EXIT” button.

8.2 Temperature Set-point

The temperatureset-point can be set to any value within the range and resolu-
tion as givenin the specifications. Be careful not to exceed the safe upper tem-
perature limit of any deviceinserted into the well.
Setting the temperature involvestwo steps: (1) select the set-point memory and
(2) adjustthe set-point value.

8.2.1 Programmable Set-points

The controllerstores 8 set-point temperatures in memory. The set-points can be
quicklyrecalled to conveniently set the calibrator to a previously programmed
temperatureset-point.
Toset the temperature one must first select the set-point memory. This function
is accessed from thetemperature display function by p ressing “SET”.The
number of theset-point memory currently being used is shown at the left on the
displayfollowed by the current set-point value.
21
8 Controller Operation
Well Temperature