“…A winch-driven helium-filled balloon made of polyester fiber material was used for measuring aloft. The following devices were mounted on the original measuring platform: two electrostatic field mills, two Gerdien chamber type sensors of air polar conductivities, sensor of radon activity Radon Scout PMT, aerosol particle counter AEROTRAK 9306v2, barometric altimeter, GPS receiver, meteorological and telemetric sensors, autonomous controlling and data collection systems, and power supply [21]. The elevation of platform varied from 2 to 500 m depending on wind speed and research program.…”