FIG. 1 is a perspective view of a pressure sensor showing our new design; FIG. 2 is a front view thereof, a rear view being identical to the front view; FIG. 3 is a right side view thereof, a left side view being identical to the right side view; FIG. 4 is a plane view thereof; and, FIG. 5 is a bottom view. The broken lines depict portions of the pressure sensor that form no part of claimed design.