Question 556Steam Plants - Assistant Engineer

The correct answer is C) axial position relative to the casing. A rotor position micrometer is used to measure the axial position of the rotor relative to the casing. This is important to monitor as changes in the rotor's axial position can indicate issues with the turbine's alignment or the development of wear in the bearings. Measuring the axial position, rather than the radial position, is the primary function of the rotor position micrometer. The other answer choices are incorrect because they do not accurately describe the purpose of the rotor position micrometer. Option A refers to the micrometer itself, not the rotor position. Option B and D refer to radial position, which is not the primary measurement taken with this instrument.