The Surge Arrester Monitoring segmentation by type is primarily divided into online monitoring and offline monitoring. Online monitoring systems embed sensors and communication modules within the arrester, delivering real‑time voltage, current, and discharge data to centralized SCADA platforms. This continuous data flow enables predictive maintenance, reduces outage risk, and commands a larger share of the market due to its alignment with smart‑grid initiatives. Offline monitoring, by contrast, involves periodic manual inspections and portable test equipment that capture arrester condition snapshots. While less capital‑intensive, it supports legacy infrastructure and niche markets where connectivity constraints exist. Both sub‑types contribute distinct revenue streams: online solutions drive higher average contract values and recurring service fees, whereas offline solutions generate volume‑based sales of testing kits and consultancy hours. Together, they shape the overall market size by balancing technology adoption cycles and investment appetites across utility tiers.