Measuring instrumentsWaveforms shall be measured by a device with memory function, for example, a storage or digital oscilloscope, or a high speed data acquisition device. Accuracy of the oscilloscope system shall be at least 0.2% of full scale. The analogue to A/D of the measurement device shall have at least 12 bit resolution (in order to maintain the required measurement accuracy).Voltage transducers (or voltage transformers) and current transducers (or current transformers) are the required sensors for measurement. The accuracy of the transducers should be 0.5% of full scale or better. It is necessary to select the transducer measuring range depending on the normal value of the signal to be measured. The selected measuring range shall not exceed 150% of the normal value of the measured signal. The transducer accuracy requirements are shown in table 1.