🔍 Key Concepts

• Axial vs. radial movement of a turbine rotor • What a micrometer actually contacts or references during operation • How rotor movement is monitored relative to fixed reference points like casing or probe body

💭 Think About

• Think about the physical direction of thrust movement in a turbine and which direction is most critical to measure during operation. • Ask yourself: does the micrometer care about the outer casing position, or about its own fixed measuring point relative to the rotor? • Consider which kind of movement (axial or radial) would be more likely measured with other instruments, such as vibration or bearing clearance indicators.

✅ Before You Answer

• Identify whether axial movement (along the shaft) or radial movement (toward/away from center) is typically associated with thrust and end-float issues. • Decide whether the micrometer reading is taken relative to the micrometer body itself or relative to the casing. • Confirm which combination of direction of movement and reference point best matches how a rotor position micrometer is mounted and used.