The ornamental design for a flowsensor, as shown and described.
FIG. 1 is a top, front, left perspective view of a flow sensor, showing our new design;
FIG. 2 is a top, front, right perspective view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines of even length shown in the drawings illustrate portions of the flow sensor that form no part of the claimed design. The broken lines of uneven length illustrate the line shadings and contours of the claimed design and form no part thereof.