Magnetoresistive sensors for angle measurements such as, for example, the sensors of the type KMZ 41, manufactured and marketed by Philips Semiconductors, utilize the effect that a sufficiently strong, external magnetic field H rotates the internal magnetization M in a parallel direction. The first and second bearing arms each have a shoulder, the shoulders being aligned adjacent one another. The serving direct-mode communication apparatus connects to the operating server, and authenticates with the operating server to obtain a serving authenticated identification. The deflection of the beam in response to the differential drag forces may be detected to determine the rate of flow of the fluid.