🔍 Key Concepts

• Impressed current cathodic protection (ICCP) systems maintain a target hull potential, not a fixed current • The reference electrode is used to sense hull potential and feed that signal to the control electronics • In an electronically regulated system, some values must change to respond to different seawater conditions and coating condition

💭 Think About

• Ask yourself: in a closed‑loop control system, which quantity is the system actually trying to keep at a set value—voltage at a sensor, current to the anodes, or something else? • Which of these options is most likely to vary when seawater resistivity, temperature, or hull coating condition changes: individual anode current, total anode current, or the sensed potential? • Think about the role of the reference electrode: is it a control input (feedback) or the thing being driven by the controller?

✅ Before You Answer

• Identify which choice represents the feedback variable that the regulator uses to decide how to adjust output • Decide which currents (individual or total) would naturally change as hull area, fouling, or paint damage change, even when the system is working correctly • Confirm which parameter would be expected to stay near a preset setpoint in a properly operating ICCP system