installing new UPS for my office and needs electrical work...

[little_scrapper]

I am still scratching my head over your blunt rod vs sharp rod statement. My understanding is that a sharper point with its tighter radius is better able to ionize the air immediately around it, and thus make that area 'more' attractive for the lightening. Yes the sharp tip would readily melt into a blunt tip once struck ... But is that not correct in that the tighter radius of a sharper tip creates a more intense field that is able to more readily ionize the surrounding air?

[westom]

I am still scratching my head over your blunt rod vs sharp rod statement. My understanding is that a sharper point with its tighter radius is better able to ionize the air immediately around it,

From Dr Charles Moore's Nov 1975 paper and from others:
"... our results indicate that the sharpened rod usually acted to protect itself by emitting ions whenever the electric field exceeded the breakdown threshold. The blunt rod, on the other hand, emitted ions with great difficulty...the fields around the blunt rod often large values that when breakdown did occur at the blunt rod a positive streamer could propagate for appreciable distances away from the blunt rod."

"Field trials in the summers of 1994-98 at Langmuir Labs have provided electric current measurements flowing from various shaped lightning rods. These were correlated to changes in electric fields caused by lightning discharges. Results of this work confirm earlier theoretical models about sharp vs blunt rod behavior. (3) Sharp rods are poorer receptors for lightning than blunt rods."

Again the point. In many fields where knowledge comes mostly from hearsay: what is popularly believed (without numbers) too often does not agree with reality.

[little_scrapper]

From Dr Charles Moore's Nov 1975 paper and from others:
"... our results indicate that the sharpened rod usually acted to protect itself by emitting ions whenever the electric field exceeded the breakdown threshold. The blunt rod, on the other hand, emitted ions with great difficulty...the fields around the blunt rod often large values that when breakdown did occur at the blunt rod a positive streamer could propagate for appreciable distances away from the blunt rod."

"Field trials in the summers of 1994-98 at Langmuir Labs have provided electric current measurements flowing from various shaped lightning rods. These were correlated to changes in electric fields caused by lightning discharges. Results of this work confirm earlier theoretical models about sharp vs blunt rod behavior. (3) Sharp rods are poorer receptors for lightning than blunt rods."

Again the point. In many fields where knowledge comes mostly from hearsay: what is popularly believed (without numbers) too often does not agree with reality.

OK sounds good. now I need one thing definded. What are we considering a "blunt" rod? Are we talking a rod where the end is like a half sphere or a pointy rod that is NOT sharp.

For example hehe:


I couldnt resist!

the reason i need the details is because i will end up making my own out of stock rod. Thats why I was asking about solid vs braided and such. Hell if i am going to pay someone thousands of dollars to do something that i can easily fabricate myself once i have the details.

[westom]

OK sounds good. now I need one thing definded. What are we considering a "blunt" rod? Are we talking a rod where the end is like a half sphere or a pointy rod that is NOT sharp.

Good question. I always only considered straight rods. However the reasons behind Dr Moore's study implies a 'balled' rod would work as good; probably better.