The Bevatron uses a system of electrodes through which the internal proton beam passes in order to continuously measure the magnitude and radial position of the beam. The bunched circulating beam induces a periodic voltage on the electrodes. This signal is amplified and displayed on an oscilloscope and also converted to direct current for operation of a recorder. Two types of electrode systems are used. The first is a large hollow box to provide beam magnitude signals for specialized monitoring and for primary calibration. The second system consists of two sets of smaller electrodes. One set provides beam radial-position information for tracking control, and the other provides beam magnitude information for magnitude control and for general distribution to experimenters associated with the Bevatron. A telemetering radio link is used to relay beam information to those in other areas. Problems associated with handling the beam signal are discussed, and the design principles involved in detection, amplification, and isolation of the signal are described. Calibration techniques, signal distribution facilities, and control features are also given. The systems described are stable and provide the desired information with a minimum of maintenance and operational difficulty. (auth)