Lightning and Electrocution

An average lightning stroke may have a rise time of 3 ps and duration of 30 ps, energy dissipated 10 J per meter, length 3 km, peak current 50,000 A, power lO W. After the main stroke there are continuing currents of typically 100 A and 200 ms duration. 

The mechanical hazards are due to the pressure rise in the lightning channel. The energy per meter is equivalent to about 22 g of TNT per meter. A direct hit from the main stroke 

It is believed that there are around 500 deaths caused by lightning per year in the United States. 

The scalp electrode is a concave metal device with a diameter about 7 cm and an area of about 30 cm. A sponge soaked with saline is used as contact medium. 

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