The ornamental design for an overflowsensortank, as shown and described.
FIG. 1 is a top perspective view of an overflow sensor tank showing my new design;
FIG. 2 is a right-side elevation view, the left side elevation view being a mirror image thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a right-side sectional view taken along lines 7-7 from FIG. 6 thereof; and,
FIG. 8 is a right-side sectional view taken along lines 8-8 from FIG. 6.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in FIGS. 1, 7 and 8 are for illustrative purposes only and form no part of the claimed design.