Xref: utzoo comp.misc:2782 sci.electronics:3271
Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!andante!mit-eddie!bbn!rochester!kodak!ornitz
From: ornitz@kodak.UUCP
Newsgroups: comp.misc,sci.electronics
Subject: Re: Lightning rods. Was: Protecting computer equipment
Summary: Pointed Rods Not Optimum
Keywords: lightning, lightning rods, discharges, protection
Message-ID: <1314@kodak.UUCP>
Date: 12 Jul 88 16:02:17 GMT
References: <1988Jul8.045005.17867@utzoo.uucp> <6179@aw.sei.cmu.edu>
Reply-To: ornitz@kodak.UUCP (barry ornitz)
Followup-To: sci.electronics
Organization: Eastman Kodak Co, Rochester, NY
Lines: 25

In article <6179@aw.sei.cmu.edu> rsd@ae.sei.cmu.edu.UUCP Rich D'Ippolito writes:
>* Electric field theory will explain the reason for the sharp point.

Several years ago, an article on the current status of lightning protection
was published in the Journal of the Franklin Institute (naturally!) by
scientists from one of the Arizona universities.  In this article, it was
shown that the sharp point is not optimum but instead an elliptical point
should be used.  This suggestion was backed up by simulation studies and the
study of several thousand actual strikes on lightning rods.  In virtually all
cases, the rods were hit several inches to several feet _below_ the pointed
tip.  The article also debunks a number of myths about the "cone of protection"
supposedly produced by a high lightning rod and also about the neutralization
of space charges by lightning rods.  If there is enough interest, I can dig
up the date of the issue.
                                       Barry  WA4VZQ

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|  ___  ________  |
| |  / /        | |  Dr. Barry L. Ornitz   UUCP:...!rochester!kodak!ornitz
| | / /         | |  Eastman Kodak Company
| |< < K O D A K| |  Eastman Chemicals Division Research Laboratories
| | \ \         | |  P. O. Box 1972
| |__\ \________| |  Kingsport, TN  37662       615/229-4904
|                 |
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