This article was posted 03/14/2008 and is most likely outdated.

Lab experiments cannot be utilized to justify the action of early streamer emission terminals
 

 

Topic - Lightning
Subject - Lab experiments cannot be utilized to justify the action of early streamer emission terminals

March 14, 2008
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Laboratory experiments cannot be utilized to justify the action
of early streamer emission terminals

 

imageAbstract. The early emission of streamers in laboratory long air gaps under switching impulses has been observed to reduce the time of initiation of leader positive discharges. This fact has been arbitrarily extrapolated by the manufacturers of early streamer emission devices to the case of upward connecting leaders initiated under natural lightning conditions, in support of those non-conventional terminals that claim to perform better than Franklin lightning rods.

 

In order to discuss the physical basis and validity of these claims, a self-consistent model based on the physics of leader discharges is used to simulate the performance of lightning rods in the laboratory and under natural lightning conditions.

 

It is theoretically shown that the initiation of early streamers can indeed lead to the early initiation of self-propagating positive leaders in laboratory long air gaps under switching voltages. However, this is not the case for positive connecting leaders initiated from the same lightning rod under the influence of the electric field produced by a downward moving stepped leader. The time evolution of the development of positive leaders under natural conditions is different from the case in the laboratory, where the leader inception condition is closely dependent upon the initiation of the first streamer burst.

 

Our study shows that the claimed similarity between the performance of lightning rods under switching electric fields applied in the laboratory and under the electric field produced by a descending stepped leader is not justified. Thus, the use of existing laboratory results to validate the performance of the early streamer lightning rods under natural conditions is not justified.

 

Link to Abstract

 

P.S. This paper is only available to be downloaded free for the next 15 days.

 

 

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Comments
  • I have given once again a simple solution to this conflict that is not to be taken lightly. This is a golden opportunity that I do not want to see used against either party. I beleive in divine resolutions if the other three parties involved do. Kind of like being a fifth member.

    Scott West
    Reply to this comment

  • Being curious, I downloaded the abstract to see if there was mention of atmospheric conditions (wind velocity, direction, tempertaure, humidity). There is mention of wind velocity. Apparently, it is these atmospheric conditions that make it difficult to simulate lightning in a laboritory, so the real test of a lightning rod would be wether your house smoked or not.

    Thanks,

    Mark Prairie
    Reply to this comment

  • I f this abstract is referring to what I think it is referring, (?), I believe there are many of these ES units installed around the country. Isn't there someway we could perhaps get a report on these locations? i.e., were any of these "early streamer unit" protected sites ever struck by lightning? Were near-by bldgs struck, while the ESU's were not? I, for one, would like to know whether these units are very good, moderately-good, a little good, or completely no-good.

    Wyatt
    Reply to this comment

  • The early stream emitter manufacturer's lost me for good when they lost that law suit to the NFPA a couple of years ago. The law suit that these manufacturer's started but the NFPA finished in a countersuit. The one where the judge forced them to take out all claims of specific coverage area's from there literature.

    The vendors of these things that I spoke to at the time were completely unrepentant.

    I tried to find out from them how I was supposed to design a system around their terminals when they weren't even allowed by law to tell me what the coverage area was in writing? The responses were interesting...

    Mike Shields
    Reply to this comment


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