The Multiplier box for a dimensioned feature (Insert | Dimension) is a scaling factor that magnifies the deviation arrows and tolerance zone by the value typed for the graphical analysis mode. If you type a 2.0 value, PC-DMIS will scale the arrows two times the calculated deviation for each feature hit.
This changes the arrow's size for viewing purposes only. It does not affect the size of the deviation in the text printout in any way.