FIG. 1 is a perspective view, showing the top, left side and front side, of a sensor of the present invention, with no claim made to the portions illustrated in phantom;

FIG. 2 is a top view of the sensor of FIG. 1; the bottom view of the senor being the same as the top view;

FIG. 3 is a front side view of the sensor of FIG. 1; and,

FIG. 4 is a left side view of the sensor of FIG. 1.