A picoammeter system has been developed and engineering. It consists in a current-voltage converter,
based on an operational amplifier with very low input current, a high precision ADC, a
radio controlled data acquisition unit and the computer-based control, visualization and storage.
The precision is of the order of a tenth of picoampers and it can measure currents between electrodes
at potentials up to 8 kV. The system is battery powered and a number of strategies have
been implemented to limit the power consumption. The system is designed for multichannel applications,
up to 256 parallel channels. The overall implementation is cost-effective to make the
availability of multichannel setups easily affordable.
The design, implementation and performance of the picoammeter system are described in detail
as well as a an application: the measurement of ion backflow in MPGD-based photon detectors.