Potential gradient is measured using an Electric field mill (CS110 Campbell Scientific). It is mounted on a 3m metal pole. Csite determined utilizing a set of typical fair weather days and considering a background PG value 100 V/m. This correction factor is applied to the raw data to derive the potential gradient.
The instrument is located at 75 m a.s.l.
Measurement frequency is 1Hz
This is used in the Glocaem potential gradient network
Publication: Kastelis N. and K. Kourtidis, Characteristics of the atmospheric electric field and correlation with CO2 at a rural site in southern Balkans. Earth, Planets Sp., 68, 3, 2016 doi:10.1186/s40623-016-0379-3