To calibrate a a Roper gas oven, the BAKE and TIME/TEMP pads on the electronic oven control are adjusted. When the calibration is complete, the START/ENTER pad is hit.
The BAKE pad is held for five seconds. At that point, the display above the pad shows the oven's calibration at that moment. The factory setting is "00." The arrows on the TIME/TEMP pad adjust the oven temperature higher or lower.
Adjustments are made up or down in increments of 10 degrees Fahrenheit. A minus sign next to a number indicates a cooler temperature, while no sign means the temperature has increased. The system does not allow a change of more than 30 degrees in either direction.
A 10 degree Fahrenheit change in temperature affects cooking slightly, while 20 degrees is a moderate adjustment. A 30 degree difference causes food to cook much more or much less, depending upon the direction of the new setting. After changes are made, START/ENTER finalizes the new calibration.
Whirlpool, which offers the Roper brand, states that the oven's temperature is accurate. However, calibration is allowed because owners sometimes want their new ovens to perform the same way their older models did. The use of an oven thermometer is not recommended, because opening the oven door to check the device sometimes throws off the reading.