What does a dial indicator measure in the context of alignment?

• A. Temperature changes
• B. Movement and deviation
• C. Sound levels
• D. Pressure variations

Answer: (B)

A dial indicator measures movement and deviation, which is crucial in the context of alignment. This device provides a precise reading of the relative position of machine components, allowing millwrights to assess how much misalignment exists. When aligning machinery, such as motors and pumps, achieving the correct alignment is vital for efficient operation and to prevent premature wear or failure of the equipment.

Using the dial indicator, a millwright can detect small changes in position as the indicator's probe contacts the surface being measured. This movement translates into a dial reading, showcasing any shifts from the desired alignment. Therefore, the ability to discern these deviations helps in adjusting the machinery to the correct specifications, ensuring optimal performance.