Do you mean a lightning arrestor? Is this the same thing as a thunder arrestor?

Naw thunder arrestors are more commonly called sound proofing.

But you can't arrest thunder, it has diplomatic immunity. You can only slow it down.

As for lightning arrestors the taller the air terminal the larger the radius.

With regards to the European lightning standard IEC 62305 (I don't know the US equivalent), roughly a rolling sphere radius of 10-30m depending on the protection level.

This probably won't make much sense to you or most people (especially since this is an incomplete answer that requires a whole lot of additional information and explanations I am not going to go into right now). Lightning protection is rather complicated (and a specialised electrical field all of its own) and is more than just putting up a bunch of metal rods and connecting them back to ground, it requires a lot of specialised knowledge to design a proper lightning protection system (for both direct and indirect lightning strike) for all but the simplest structures.

Have a look at wikipedia and the internet for more general information on the subject to start with. Also below is a link to a major European supplier of lightning protection systems (to give you an idea on the different elements that make up a proper system).

http://www.dehn.de/design07_frame/english/products/prod_eb_ext.html

Do you have any specific questions?

Hello There

There nothing like a "Thunder Arrestor", its is actually a "Lightning Arrestor"; Usually a bare copper rod 2 to 5 meter long, attached to a copper earthing grid .

These arrestors are usually to get a 45 Deg cone of protection for below structures.

Mohammed.fareeduddin@ericsson.com

This is the basics of what I was taught some years ago, though back then it was only 30 Deg cone.

Someone then decided that it was too expensive to build towers tall enough, so the guidelines were re-defined at 45 Deg.

I suspect that these are only guidelines and that as others have suggested there is now the capability to "put some science" into the answer for specific examples and models.

Hi cyclo. Please have a look at an earlier thread this month....

http://cr4.globalspec.com/thread/35770/Locations-for-Lightning-Arrestors?frmtrk=CR4digest

Hope that will help you a little.