We claim the ornamental design for a pipe sensor unit, as shown and described.
FIG. 1 depicts an isometric view of a pipe sensor unit.
FIG. 2 depicts a side view of the pipe sensor unit of FIG. 1; the left and right side views are mirror images of each other.
FIG. 3 depicts a front view of the pipe sensor unit of FIG. 1.
FIG. 4 depicts a back view of the pipe sensor unit of FIG. 1.
FIG. 5 depicts a top view of the pipe sensor unit of FIG. 1.
FIG. 6 depicts a bottom view of the pipe sensor unit of FIG. 1.
FIG. 7 depicts an off-angle view of the pipe sensor unit of FIG. 1; and,
FIG. 8 depicts another off-angle view of the pipe sensor unit of FIG. 1.
Broken lines are used to depict features or elements that are not considered to be part of the claimed design; the dash-dot-dash boundary line in FIGS. 6 and 8 indicates a transition between claimed and unclaimed subject matter.