Which material is NOT acceptable for air terminals?

The choice of materials for air terminals in lightning protection systems is crucial for ensuring optimal performance and safety. Air terminals, also known as lightning rods, need to effectively conduct lightning strikes to the ground.

Galvanized steel is not considered an acceptable material for air terminals because it can corrode over time, particularly when exposed to the elements. The zinc coating that provides galavanization will eventually wear away, exposing the underlying steel, which is susceptible to oxidation and further degradation. This corrosion can significantly decrease the effectiveness of an air terminal over time, compromising the lightning protection system's performance.

In contrast, materials like stainless steel, copper, and brass are typically favored for air terminals due to their excellent conductivity and resistance to corrosion. Stainless steel offers good tensile strength and resistance to environmental factors, making it a reliable choice. Copper is highly conductive and has natural corrosion resistance, which ensures longevity. Brass, while less commonly used than copper, also provides good conductivity and resistance to corrosion, making the material suitable for lightning protection applications.

The selection of appropriate materials for air terminals is essential to maintain the efficacy and durability of a lightning protection system.