Your cart is currently empty!
Franco D’Alessandro
Chief Technology Officer | Lightning Protection International Pty Ltd
This presentation reveals some of the new research findings associated with air terminals used for protecting structures, sites, facilities, and critical assets in general, against direct lightning strikes. The new research findings related to the effect of accumulated “corona space charge” around the tips of air terminals. There is now a great deal of consensus across the lightning community that space charge accumulation reduces the efficiency of an air terminal by inhibiting the initiation and development of an upward leader, a critical stage in the lightning attachment process.
The presentation describes measurements carried out in a high-voltage laboratory to quantify the amount of corona discharge that would be emitted under thunderstorm conditions from a variety of air terminals of different geometries. A unique, previously unreported aspect of these experiments was the corona testing of air terminals under dry and wet conditions. The results of these experiments showed that corona discharge (and hence space charge accumulation) from a standard Franklin rod is substantially higher than from the range of significantly blunter “corona minimising” air terminals that were tested.
Based on years of calculations and field experience, general guidance will be provided on what constitutes the “optimum air terminal geometry” for a range of practical installation scenarios.