In vibration analysis, what does "low frequency" typically refer to?

In vibration analysis, "low frequency" typically refers to frequencies below 1 kHz. This categorization is important because vibrations within this range are often associated with various mechanical systems and structural responses to operational conditions, making them critical for assessing machine health. Low-frequency vibrations can indicate issues such as misalignment, imbalance, or bearing problems in equipment.

Understanding the frequency spectrum in vibration analysis helps technicians and engineers target specific mechanical problems effectively. By distinguishing low frequencies, analysts can focus on the most relevant data that correlates with potential fault conditions in machinery.

The other options incorporate frequencies that either shift into different ranges or are not relevant to the typical analysis scope in machinery and structural health monitoring, making them less suitable for defining "low frequency" as used in this context.