In one example implementation, a sensor apparatus includes a bracket, a first polar plate, a first contact portion, a first leading wire, a rotating shaft, a support frame, a second polar plate, a second contact portion, and a second leading wire. The bracket is of a cylindrical structure with two open ends. The first leading wire is disposed on the first polar plate and an external side of the bracket, one end of the first leading wire is connected to the first contact portion, and the other end of the first leading wire is connected to the first polar plate. The second contact portion is disposed at a first end of the support frame. The second leading wire is disposed on the support frame and the second polar plate.