Which tool is commonly used to detect misalignment in rotor shafts by comparing to a reference plane?

Which tool is commonly used to detect misalignment in rotor shafts by comparing to a reference plane?

• A. Dial indicator
• B. Shaft gauge
• C. Protractor
• D. Micrometer

Answer: (A)

Detecting rotor shaft misalignment against a fixed reference plane relies on sensing tiny changes in position with high precision. A dial indicator is designed for exactly this kind of task: it converts small linear movements into readable rotations on a dial. By mounting it on a stable stand and touching its probe to a reference point on the shaft or coupling, you can rotate or move the shaft and watch for deflections. If the readings stay nearly constant, the shaft is well-aligned; if the dial shows fluctuations, you’ve got offset or angular misalignment to correct. This level of precision, usually in thousandths of an inch or hundredths of a millimeter, is why the dial indicator is the go-to tool for comparing a shaft to a reference plane. Other tools aren’t as suited for this specific purpose: a shaft gauge is less precise for alignment against a plane, a protractor gives rough angular data, and a micrometer measures size rather than positional alignment.

Detecting rotor shaft misalignment against a fixed reference plane relies on sensing tiny changes in position with high precision. A dial indicator is designed for exactly this kind of task: it converts small linear movements into readable rotations on a dial. By mounting it on a stable stand and touching its probe to a reference point on the shaft or coupling, you can rotate or move the shaft and watch for deflections. If the readings stay nearly constant, the shaft is well-aligned; if the dial shows fluctuations, you’ve got offset or angular misalignment to correct. This level of precision, usually in thousandths of an inch or hundredths of a millimeter, is why the dial indicator is the go-to tool for comparing a shaft to a reference plane. Other tools aren’t as suited for this specific purpose: a shaft gauge is less precise for alignment against a plane, a protractor gives rough angular data, and a micrometer measures size rather than positional alignment.