industrial instrumentation basics

This set of 45 questions goes beyond the fundamentals covered in our Top 50 Instrumentation Interview Questions post — these lean toward practical field scenarios, control strategy, safety systems, and digital communication topics more likely to come up in interviews for experienced instrumentation engineers, supervisors, or senior technician roles. Control Strategy Q1. What is cascade control, and when would you use it? Cascade control uses two controllers in a nested loop — an outer (primary) controller sets the setpoint for an inner (secondary) controller, which responds faster to disturbances. It's used when a process has a fast-responding intermediate variable that can be controlled tighter than the final variable alone — for example, a temperature controller (primary) setting the setpoint of a flow controller (secondary) on a steam valve. Q2. What is feedforward control, and how does it differ from feedback control? Feedback control reacts after a deviation from se...