Accelerators with superconducting magnets have special requirements for beam current measurement. Two different systems to measure beam current in the HERA proton ring are presented: a.) A Parametric Current Transformer (d.c to 100 kHz) measures the total circulating beam current in the ring and provides the absolute calibration. b.) The Bunch Current Monitor is a specialized system for low values of beam current. It features an Integrating Current Transformer as a beam sensor and signal processing with a new combination of charge amplifier and dual gated integrator to restore the d.c. baseline reference. The large dynamic range and high resolution permit fast beam lifetime measurements at low values of beam current.