As the core component of lightning protection systems, proper lightning rod selection directly impacts building safety. The decision should balance technical specifications, environmental factors, and regulatory compliance.
1. Type Selection by Functionality
Franklin Rods: Suitable for residential buildings with 30m protection radius. Require galvanized steel construction and dedicated grounding grids.
ESE (Early Streamer Emission) Rods: Extend coverage to 100m using electronic triggering, ideal for critical facilities like data centers. Verify CE/UL certifications.
Radioactive Rods (Restricted) : Prohibited in new Chinese constructions per GB 50057 since 2005 due to radiation hazards.
02. Environment-Specific Engineering
Height Calculation: Apply rolling sphere method $ h = \sqrt{2rH – H^2}$ (h: rod height, r: sphere radius, H: structure height)
Corrosion Resistance: Use 316L stainless steel (salt spray resistance >720hr) in coastal areas; copper-titanium alloy (pH 2-12 tolerance) for chemical zones
Lightning Density: In high-activity regions (>90 annual thunderstorm days), increase grounding electrodes by 25%.
03. Code-Compliant Installation
Design Phase: Maintain ground resistance <10Ω (<4Ω for special facilities), implement TN-S/TT earthing systems
Construction: Apply thermite welding for air terminals/down conductors with >12cm overlap
Inspection: Test impulse impedance via CDM-10 pulse current meters; verify bonding with infrared imagers
Maintenance Tip: Monitor ground resistance with micro-ohmmeters bi-annually, replace down conductor coatings every 5 years to ensure IEC 62305 compliance throughout the protection lifecycle.