The ornamental design for a pipettorheadassembly, as shown and described.
FIG. 1 is a front, right side and bottom perspective view of a pipettor head assembly;
FIG. 2 is a back, left side and top perspective view of the pipettor head assembly;
FIG. 3 is an enlarged perspective view of the pipettor head assembly taken along lines 3-3 in FIG. 1;
FIG. 4 is a right side view of the pipettor head assembly;
FIG. 5 is a left side view of the pipettor head assembly;
FIG. 6 is a bottom view of the pipettor head assembly;
FIG. 7 is a top view of the pipettor head assembly;
FIG. 8 is a front view of the pipettor head assembly; and,
FIG. 9 is a rear view of the pipettor head assembly.
The broken lines in FIG. 7 view are included for the purpose of illustrating portions of the pipettor head assembly that form no part of the claimed design.