Shellab SMO5HP-2 - Manual (Page 18)

18 | P a g e
OPERATION (CONTINUED)
Note: The accuracy of the calibration process is limited by the accuracy of your reference
temperature device.
The difference between the reference device and oven’s display is called an offset.
Examples of offsets:
Reference Sensor
Reading
Watlow Temp.
Display
Offset
Value
152°C 150°C 2
148°C 150°C -2
Note: If the door was opened to check the reference device’s reading, allow the oven
temperature ten minutes to stabilize before entering the offset.
9. Enter the temperature offset into the Watlow Controller. To do so, push and hold both
the Up and Down Arrow Button simultaneously for three (3) seconds or until “Ai”
appears in the Upper Display and “oPEr” appears in the Lower Display.
10. Push the green Advance Button repeatedly unit “i.CA” appears in the green middle
display and a number value shows in the red top display.
11. Adjust the number value in the top display using the Up or Down Arrow Buttons to
match the offset value.
12. Once the Offset Calibration Number is entered, push the Reset Button repeatedly to
exit the calibration, save the set point, and return to the Home Page.
13. Wait for a half hour, then compare the reading of the reference device and the Watlow
Controller. Enter an offset if the readings are still different and fall outside your laboratory
protocol range.
14. If the temperature readings of the display and the reference device still do not fall close
enough to be acceptable by your laboratory protocol after three calibration attempts,
contact Sheldon Technical Support for assistance.
Note: After calibrating the oven to your process or application temperature, set the Over
Temperature Limit to 5
°C above the process / application’s set point. If you will be running a
programed heating profile, set the Over Temperature Limit to 5
°C above the profile’s highest
set point.
End of Procedure