# Calculating Offset Value

### What is the offset value?

In situations where the actual tip temperature varies from the preset temperature on the soldering station, you may input an offset value to achieve a consistent reading.

The offset function stores the current tip temperature in the station. Inputting the offset value correctly enables the “tip temperature” to be the “set temperature”, which offers you a correct temperature.

The offset value input method varies with its product, kindly read the product's instruction manual to know the offset value input method. In the event that the instruction manual does not reflect the method, kindly reach out to our sales staff for assistance.

The example here is for the Hakko FX-951 Soldering Station.

Actual Tip Temperature > Preset Temperature ➜ Negative Offset Value

If the tip temperature is higher than the set temperature, input a negative offset value.

Step 1: Measure the tip temperature and get the difference in temperature.

For example:

• Set temperature = 360ºC
• Actual tip temperature = 395ºC
• Difference in temperature = -35ºC

Step 2: Press the "#" button to check the current offset value.

For example: Current offset value = 010

Step #3: Calculate the new offset input value

Current offset value + Difference in temperature = New Offset Input Value

010 + (-35) = -25

The new offset input value should be -25.

Actual Tip Temperature < Preset Temperature ➜ Positive Offset Value

If the tip temperature is lower than the set temperature, input a positive offset value.

For example:

• Set temperature = 400ºC
• Actual tip temperature = 360ºC
• Difference in temperature = +40ºC

Step 2: Press the "#" button to check the current offset value.

For example: Current offset value = -10

Step #3: Calculate the new offset input value

Current offset value + Difference in temperature = New Offset Input Value

-10 + 40 = +30

The new offset input value should be 030.

After calculating the new offset value, it is now time to calibrate your soldering station to reflect the new value