🚀 go-pugleaf

I agree with those who claim that, depending on conditions, a lightning rod
may either attract a powerful discharge or prevent it. Both effects prevent
disasters (when the cable is thick and well grounded). But I have no evidence
to support this position. It is a matter of believing in reasonable arguments
and speculations. Does anybody know how frequent powerful and quiet discharges
are?

What would I do if ordered to collect such data? I would look for a building
on top of a mountain, preferably with a flat roof. A large metallic plate
(without sharp edges) would be placed on the roof and grounded by a competent
builder. Then I would define what is meant by a "powerful discharge", for
example, a discharge in which the current is more than 10 A. An automatic
counter of such discharges would have to be installed. The rest is simple.
I would count the number of "strong hits" for one year. Then a long vertical
spike would be welded to the plate and hits counted for another year. Suppose
the result is 200 in the first year and 50 (or maybe 500) in the second. The
rest is a matter of statistical significance, etc.

Naturally a conclusion drawn from what happens at the top of a mountain is
not necessarily valid for a flat area but at least one clear set of data
would be available for a protective system of one kind. A better, and much
more useful, experimental setup would record the magnitude of passing charge
Q in each hit. A distribution of Q would be interesting. Well, I suppose that
data of that nature are available. It would certainly be useful if somebody
could find them and share with the rest of us. If the data do not exist then
perhaps somebody can collect them. What a project! Do not forget, however, to
consult those people who have experience with lightning rod protectors.

          Ludwik Kowalski       kowalski@apollo.montclair.edu