To get the lowest splice loss possible, it is necessary to adjust the arc power parameters of the fusion splicer to match the fiber being spliced.

The loss estimate provided by the fusion splicer is an estimate based on the shape of the fiber splice, assuming the fibers being spliced are the same type, and the fusion splicer settings have been optimized. So we are going to adjust the parameters until we achieve an optimal real dB loss.

Target loss levels
When splicing two fibers of the same type together, the following losses should be able to be achieved.
SM 0.02dB
MM 0.01dB

When splicing two different brands of fibers together, the following losses should be able to be achieved.
SM 0.04dB
MM 0.02dB
Program Check
When adjusting the arc of the fusion splicer to match the characteristics of the fiber, the first parameters to adjust are the PreArcPower and ArcPower. The easiest way to set the correct PreArcPower and ArcPower levels is to do a Program Check.

Follow these steps to do a Program Check:

1. Turn on fusion splicer.

2. Clean and cleave fibers. Load cleaved fibers into the splicer.

3. Go to the main menu and press to enter the “Setup Menu”

4. Use the arrow keys ( and  )to move to “Program Check” and press to select.

5. Press to begin the Arc test.

6. The fusion splicer will report “Arc Weak”, “Arc Strong”, or “Arc Good”. This report is based on the size of the gap between the glass fibers after the arc.

7. If the arc is good, press to reset, and proceed with splicing.

8. If the arc is too weak or too strong, press and the fusion splicer will automatically adjust the PreArcPower and ArcPower parameters accordingly.

9. Return to step 2 to repeat the Program Check. This check may need to be done several times to reach the correct settings.

Some more user tips for setting parameters are now posted at advanced Y70 fusion splicer settings