Stationary Data Loggers: Don't Leave Home without Them

Abstract Stationary Data Loggers (SDLs) provide long-term monitoring capabilities that have become essential for modern cathodic protection (CP) assessment. The CP industry primarily utilizes SDLs to monitor alternating current (AC) and direct current (DC) potentials and current over extended periods, offering insights unavailable through traditional instantaneous measurements. While monitoring AC voltages and current densities is frequently discussed due to the desire to monitor time-weighted averages, DC potential monitoring is less common and can reveal dynamic system changes during surveys that single-point readings cannot capture. This paper presents lessons learned from comprehensive SDL deployments that recorded AC voltage, DC voltage, AC current, and DC current values across decades of data points collected during field surveys. The paper examines advanced analysis tools utilized to process and interpret SDL datasets, demonstrating how continuous monitoring transforms raw data into actionable insights. Examples highlight how SDL data reveals system behaviors, environmental influences, and performance trends that guide optimization decisions and predictive maintenance strategies. SDLs have evolved into essential tools for proactive CP management, enabling data-driven decisions that improve system performance and reduce costs in corrosion control planning.