Abstract— <p>A system for probe measurements of a powerful pulse–periodic discharge has been developed, which makes it possible to determine the plasma characteristics at various instants of time. The system consists of hardware and software parts. The hardware includes probes with a sensor unit and a data acquisition board with signal preparation units and a probe power-supply amplifier. To create a controlled probe-voltage source, a high-power high-voltage amplifier with an output-voltage range from –85 to +85 V and a maximum output current of 700 mA has been developed. The measured voltages from the probe, as well as the amplifier input, are connected to the data acquisition board via galvanic-isolation units, which is a prerequisite for precision measurements under conditions of significant interference caused by the power part of the facility. The use of a storage sampling system makes it possible to obtain the current–votage (I-V) characteristics in real time. The software part includes a functionally complete program intended to control the process of recording the I–V characteristics.</p>