Potential gradient is measured using a Boltek EFM-100. It is mounted on a 0.6 m metal pole.
The provided data was calibrated using long-term observation of water dropper data (Nagamachi et al, Geosci. Data J., 2021). The resolution of the sensitive data provided through GLOCAEM is 1.9 V/m and the measurement range is from -3.8 kV/m to +3.8 kV/m. GPS-synchronized data with higher resolution (0.19 V/m) and with high sampling (10 Hz), all-sky camera images (10 min. sampling), animal camera images (motion detection) and are also available through on-demand request.

The instrument is located at 27 m a.s.l.
Measurement frequency is 1Hz

This is used in the Glocaem potential gradient network