INRIM JAWS quantum steps, margins and uncertainty analysis

The data collected within the project "Research on possibility of functionality improvement of ac quantum voltage standard" funded by Polish National Science Centre (grant no. 2022/06/X/ST7/00014). The data is associated with articles "Verification of thermal converters by means of a pulsed Josephson standard" (https://doi.org/10.21014/tc4-2023.15) and "Direct calibration of a true-rms ac voltmeter against a He-free pulsed Josephson standard" (https://doi.org/10.1016/j.measurement.2024.114981).