Boltek EFM-100 Electric Field Monitor measures the static electric field generated by thunderclouds electric field in Volts per meter (measurement accuracy 5%). Lightning is detected as a sudden change in the static electric field.
EFM-100 can
• Log date, time and distance of nearby lightning.
• Monitor lightning up to 38 km away.
• Detect the high electric field conditions which precede lightning.
• Short-range detector is optimized for close lightning to provide the best distance accuracy while ignoring far away lightning.
• Monitor up to four separate locations per PC.
• Watch trends develop.
• Attention getting alarms.
• Review archived data from previous storms.
• Stay current with free software updates from the Boltek website.

It is mounted on a ~7m on the roof of Nor-Amberd guest house building in the Nor Amberd Research Station, near to the weather station. Calibration of the field meter alongside was performed on September of 2011