Despatch DES2000 Controller - Manual (Page 16)

10
Oven Zone Calibration
The CONTROL instrument has been tested and calibrated at the factory. Under normal
operating conditions, recalibration should not be necessary. However, if the instrument
does not comply with known standards, OR if the user would like to recalibrate the
CONTROL for a specific operating condition, then recalibration is easily accomplished.
Calibration Instructions
(Equipment needed: Temperature Measuring Device with a Compatible Temperature
Sensor)
1. Verify that the bS (PV Bias) operating parameter in the control is programmed to
0. Refer to Instructions on viewing the parameter in the OPERATING mode in
the Appendix of this manual.
2. Locate the temperature sensor of the temperature measuring device at the
center of the chamber.
3. Operate the oven until it reaches the desired operating temperature and the
CONTROL is cycling the heater on and off. The user may wish to have a loaded
chamber with a standard amount of product to simulate a specific operating
condition. It will take several minutes for the unit to stabilize at the controlled
temperature. Allow at least 30 minutes of operation at the stabilized temperature
before proceeding.
4. Subtract the average controlled temperature (number appearing on the
CONTROL display) from the actual oven temperature (number appearing on the
temperature measuring device display). The CONTROL and the device must be
in the same scale (°C or °F).
Actual Oven Temperature - Controlled Temperature = calculated value
5. Enter the calculated value from Step 4 as the new bS (PV Bias) value in the
instrument.