Electric Field

Electric Field Monitor Boltek EFM-100

Measuring the Boltek EFM-100 not only detects nearby lightning but can detect the atmospheric conditions which precede lightning. 

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. 

The electric charge contained in a thundercloud also generates an electric field. This field can be measured on the ground. 

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.
More information about the Boltek EFM-100 can be found at the manufacturer's website

Figure 1: Electric Field Monitor Boltek EFM-100