The 700 Series controllers permit the operator to select a display offset
temperature. With a display offset entered, the temperature displayed will
be the actual oven temperature (measured at the control thermocouple)
plus or minus the display offset selected. Functionally, the offset feature
permits the operator to measure and calibrate such that the display will
indicate the temperature at a specific point or zone within the oven. To
enter a display offset, carry out the following steps:
1. Press the MENU, the display will indicate CAL
2. To view the present offset value, press and hold the SET key.
3. To change the display offset, press and hold the SET key. Press
INCREASE or DECREASE until the display indicates the desired
offset.
4. Release the SET key.
5. Press MENU once to return to normal temperature control.
Examples:
1. The displayed temperature is the result of algebraically adding the
actual temperature to the offset value. Thus, if an offset of -3° is being
used, a measured temperature of 50° degrees will be displayed as 47°.
2. A test is to be performed at 150°C in the center of the oven and
temperature is critical. Place a thermometer or thermocouple
(calibrated) at the critical point and set the oven to 150°C and allow
the oven to stabilize. The calibrated thermometer reads 151°C. A
display offset of 1 is entered. The immediate display reads 151. The
oven cools to 150°C, the display reads 150, and the calibrated
thermometer reads 150.
Isotemp Premium Ovens
5-3
Fisher Scientific
Section 5
Operation
Display Offsets
