Characterization and Verification of Suitability of a Digitizer for Lightning Impulses

This paper discusses the requirements and the performance of the recording instruments used in high voltage impulse measurements. The target of high accuracy and in the same time fast settling without creeping behaviour are the key issues of this work. Therefore, one of the most promising digitizers on the market was tested in linearity and temperature dependence as well as the performance at step voltages. It has been found that the linearity and the temperature behaviour can be corrected to a residual negligible influence. The step response directly after the step, which is the best indicator for the performance of transient recorders, must be below 1 % of the step voltage for approved transient recorders and should be below 0.5 % for reference transient recorders [1]. Even the reference requirements could be achieved using the chosen digitizer. The results of the characterization as well as the assessment of the digitizer in the measuring setup of the PTB (National Metrology Institute of Germany) is shown in this paper.