Question 566General Subjects - Assistant Engineer

The correct answer is D) Normal. Vibration characteristics are measured under normal operating conditions in order to establish a baseline signature or check the mechanical condition of machinery. Measuring vibration under normal load and speed allows for the establishment of a reference point against which any changes or abnormalities can be detected. Measuring vibration under low or high torque, or under abnormal conditions, would not provide the necessary baseline data to effectively evaluate the mechanical health of the machinery.