instrument must be at temperature and stable prior to taking the set-point resis-
tance reading.
Todisplay the Set-point Resistance, press “SET” and “DOWN” simultaneously
when the temperature is displayed. When the “SET” and “DOWN” buttons are
released the temperature is again displayed.
99.222 Current set-point resistance setting is displayed

6.7 Secondary Menu

Functions which are used less often are accessed within the secondary menu.
The secondary menu is accessed by pressing “EXIT” while holding down
“SET” and then releasing both. The first function in thesecondary menu is the
heater power display.

6.8 Heater Power

The temperature controller controls the temperature of the well by pulsing the
heater on and off. The total power being applied to the heater isdetermined by
the duty cycle or the ratio of heater on time to the pulse cycletime. By knowing
the amount of heating, the user can tell if the calibrator ish eatingup to the
set-point, cooling down, or controlling at a constant temperature. Monitoring
the percent heater power, allows the user to know the stability of the well tem-
perature. With good control stability the percent heating powershould not fluc-
tuate more than ±1% within one minute.
The heater power display is accessed in the secondary menu. Press “EXIT”
while holding down “SET” and then release both. The heater power is dis-
played as a percentage of full power.
100.00C Well temperature
S+E Access heater power in secondary menu
SEC Flashes SEC for secondary menu and then displays the
heater power
12.0P Heater power in percent
Toexit out of the secondary menu press “EXIT”. To continue on to the propor-
tional band setting function press “SET”.
27
6 Controller Operation
Secondary Menu