A “Collection Volume Method” for the placement of air terminals for the protection of structures against lightning

Attachment of lightning flashes to grounded structures

“…Due to the theoretical and practical difficulties to either approve or reject these new devices [30], there is an ongoing controversy between scientists and manufacturers about the validity of these claims and the efficiency of these devices. In addition, new methods have been proposed by ESE manufacturers for positioning of lightning rods given the limitations of the current lightning 18 protection practice [32][33][34]. These methods have also been subject of discussion and controversy [35,36].…”

“…Petrov and Waters [96] proposed a leader inception criterion based on the length of the streamer zone and the range of electric field intensification produced by the presence of a grounded object. For this reason, it is usually called the field intensification model [32]. It assumes that a positive upward leader can successfully develop when the streamers from the structure ex-tend beyond a critical length equal to 0.7 m. The electric field over the streamer zone must exceed a value equal to 500 kV m -1 .…”

“…For these reasons, there is a considerable world-wide interest on the development of improved methods for location of lightning rods on complex and vulnerable structures [120]. This interest has also been motivated by the recent controversy about the efficiency of early streamer emission (ESE) terminals [30] and the new methods proposed for positioning of lightning rods [32].…”

“…Due to its empirical nature, the rolling sphere method cannot provide any scientific or technical information to either reject or accept this kind of devices. For the same reason, the rolling sphere method has not been useful either for the discussion of the recently introduced air terminal positioning methods [32,33,34].…”

“…However, the interception distances from the corners of the structure could not be considered since this analysis was only performed in two dimensions [72]. Later, the collection volume concept proposed by Eriksson [62,63] for free standing structures was used for the analysis of lightning strikes to buildings [32], together with electric field intensification factors [93]. Even though this method is claimed to be validated with field observations [127,128], there are still doubts in the lightning community about its use [35,36,120].…”