RCO Training – Mechanical Practice Test

Dial indicators provide a precise readout of tiny linear displacements, and they’re ideal for detecting runout during machine alignment. When you mount the indicator to touch a reference surface on a rotating part and rotate it, the dial shows how far the surface deviates from true circular motion. The goal is to minimize that runout so the spinning component is as true and concentric as possible. This dynamic measurement gives a direct, quantitative way to verify and improve alignment. Other tools like micrometers measure static dimensions, torque wrenches measure torque, and vernier scales read linear distances, but they don’t track runout during rotation, which is why this tool is used for alignment checks.