Is there any guidance that would tell them the effect of a blunt end on air terminals?
Most manufacturers or dealers will have access to a variety of strike termination devices, including pointed rods, blunt rods, rods with metallic balls at their top ends, or taller than standard rod configurations. The pointed rod may be the more standard version of a terminal, and we think its popularity stems from the viewpoint that a slender pointed rod tends to disappear from the eye architecturally. You may hear several things, like a pointed rod bleeds off ions easier, but there is little engineering evidence to support this. Most likely there are economic benefits and aesthetic benefits to the pointed rod configuration. The Standards do not specify a taper or point configuration, and if you compare manufactured products you will see a variation in the taper of different products. There is a very good paper written by Charles Moore of New Mexico Tech showing field research findings at Langmuir Laboratories where blunted rods did a better job of accepting lightning strikes than po
