The Design of an Automated Plasma Diagnostic System – From Measurement to Signal Processing

Abstract

The paper deals with the design of a new plasma diagnostic system consisting of a microcontroller based power supply for automatic control of the measurement using Langmuir probe, the communication interface of the power supply and the signal processing program. The main motivation for the design of the automated plasma diagnostic system was given by our research in different methods of plasma nitriding of steels. During the nitriding process, it is important to achieve information about the plasma, which is the medium where the heat-treatment process is going on. The new diagnostic system is able to perform measurements during the nitriding process, thus we can analyze the plasma at different temperatures and gas mixtures. The obtained voltage-current curves are recorded and transmitted to the computer, where further signal processing is performed. The paper presents the design of the power supply, the measurement results and the developed signal processing software.