The ornamental design for a measuringinstrument, as shown and described.
FIG. 1 is lower perspective view of the measuring instrument of my new design;
FIG. 2 is a top plan view of the measuring instrument of my new design;
FIG. 3 is a bottom plan view of the measuring instrument of my new design;
FIG. 4 is a left side view of the measuring instrument of my new design;
FIG. 5 is a right side view of the measuring instrument of my new design;
FIG. 6 is a front end view of the measuring instrument of my new design; and,
FIG. 7 is a rear end view of the measuring instrument of my new design.
The broken line showing of structural features is included for the purpose of illustrating non-claimed subject matter and forms no part of the claimed design.