This dataset contains the radiosonde and additional sensor data for an adapted radiosonde launched on the 22nd September 2017 from Pallas at 0915 UT. The file contains standard meteorological data and the additional sensor channels that were used in the analysis shown in the Review of Scientific Instruments note: A self-calibrating wide range balloon electrometer by R. Giles Harrison, Graeme J. Marlton, Keri A. Nicoll, Martin W. Airey, Paul D. Williams.