The Hakko FR-860 Preheat Plates are factory adjusted to be within specifications, however if you have a specific requirement to calibrate the unit, the following steps should be followed.

Part 1 - Unlocking the Controller

1. Turn the power ON for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button until the display blinks 1 time, then release the MODE button
4. Press the FUNC button one time and release
5. Press the MODE button one time and release.  The display will read _Su1 with a value of ON
6. Press and hold the MODE button until the display reads SET1 with a value of OFF, then release the MODE button
7. Press the FUNC button to change the value to ON.  THis will make the key lock and gain correction settings available.
8. Press the UP button.  The display will read SET2 with a value of OFF
9. Press the FUNC button to change the value to ON.  This will make the setting limits accessible.
10. Press and hold the MODE button until the display reads _Su1 with a value of ON, then release the MODE button
11. Press and hold the MODE button again until the display reads _C/F with a value of OFF, then release the MODE button
12. Press the FUNC button to change the value to ON.  This will make the option to change between °C and °F accessible.
13. Turn the power OFF on the Hakko FR-860 Preheat Plate to store the new settings.

Part 2 - Changing the Key Lock Setting

1. Turn the power ON for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button for more than 2 seconds.  The display will show SET with a value of 1
4. Press the MODE button until the display shows _LoC with a value of 3
5. Press the UP or DOWN buttons to adjust the value to 0 which removes the locks on adjusting the controller
6. Turn the power OFF on the Hakko FR-860 Preheat Plate to store the new setting

Part 3 - Adjusting the Correction Gain (Calibration)

1. Turn the power ON for the Hakko FR-860 Preheat Plate
2. After 5 seconds, the PV and SV values will appear on the face of the controller
3. Press and hold the MODE button for 5 seconds.  The display should read SET with a value of 1, then release the MODE button.
   NOTE:  If not, press the UP or DOWN buttons until the display reads accordingly.  If the display will not read SET with a value of 1, then the controller is still locked (See Part 1)
4. Press the MODE button two times and release.  The display will read _PuG with a factor default value of 0.97
5. Press the UP or DOWN buttons as needed to adjust the value as needed.
   NOTE:  If the temperature displayed on the controller is lower than the measured temperature of the plate surface, increase the value. ; If the temperature displayed on the controller is higher than the measured temperature of the plate surface, decrease the value.
   IMPORTANT:  Be sure to measure the plate surface temperature using a Type K thermocuple that has been properly attached to the geometric center of the plate surface.  Use of spot IR non-contact thermometers is not recommended due to the properties of the plate surface.
   IMPORTANT:  Adjustment of the correction gain must be done as a set - controller to plate.  Interchanging controllers or plates will require readjustment if accuracy is critical.
6. Turn the power OFF on the Hakko FR-860 Preheat Plate to store the new setting.

After the adjustment has been completed, turn the Hakko FR-860 Preheat Plate on and allow it to stabilize at the set temperature for 30 minutes before making a temperature measurement of the plate surface.  Repeat the steps in Part 3 above as needed.