8-2
3177885 Thelco Oven
Thermo Electron Corporation
Section 8
Maintenance and Servicing
Temperature Offset
A temperature offset may be required to match a stable oven's actual
temperature display to a calibrated thermometer. This is normal and can be
adjusted as follows:
1. Allow the oven to stabilize.
2. Press the TEMP button twice; the Actual display will read "OFF".
3. Press the arrow buttons to make the SET POINT display agree with the
calibrated thermometer reading.
4. Press SET. The SET POINT display will show the desired set point. The
ACTUAL display will agree with the thermometer. The oven will heat or
cool as required to the desired set point.
Note
A resistance decade box capable of .01 ohm resolution is required for
this procedure.
V
1. Turn oven power off and disconnect from power.
2. Open control panel by removing top screws which secure it. Lift and pull
out.
3. Disconnect temperature sensor from CPU board and replace with decade
box set at 100.00 ohms.
4. Reconnect oven to power source.
5. Press SET button while turning oven on.
6. Press SET button again, and use the up arrow button to make the
display read "12". Press the set button again.
7. Be sure the decade box is set to 100.00 ohms, then press the down arrow
button. The display should read "100". Press the SET button.
8. Set the decade box to 200.00 ohms, then press the down arrow button.
The display should read "200". Press the SET button.
9. The oven is now calibrated. Turn oven power off and disconnect from
power. Remove decade box and reconnect temperature sensor.
10. Close control panel and secure.
Calibration (Digital
Models Only)
