[en] Two systems are described which operate in high noise environments and detect weak (nanoampere to microampere) signals. Polarized beam is injected in the Zero Gradient Synchrotron (ZGS) and stopped just downstream of long straight section three (L-3). The L-3 section contains a vertically segmented Faraday screen from which a radial profile of injected beam is obtained. The microampere currents are sensed by a bank of 44 operational amplifiers, multiplexed and displayed by a computer. The resonantly extracted polarized proton beam requires good control for a successful physics program. An ion chamber and associated electronics are described which provide three control parameters. Extracted beam intensity, instantaneous spill rate, and horizontal position information are generated and provided for feedback control of the extracted beam