1. Vibration

2. Vibration is simple or complex oscillatory motions.

3. Human Exposure Human vibration exposure is measured by its properties: –Magnitude of acceleration –Frequency –Direction –Exposure time

4. Root-Mean-Square The magnitude of vibration is typically expressed as RMS (Root-Mean-Square) acceleration (m/sec 2 ).

5. Frequency Frequency is the rate at which a vibrating object oscillates. Frequency is reported as cycles per second or hertz (Hz). Frequency is mechanically related to the speed of moving parts or equipment.

6. Directional Measurement Human vibration measurements are always referenced to a directional coordinate system of three orthogonal axes.

7. Measurement of Whole-Body Vibration The convention to measure whole-body vibration direction is based on te international standard coordinate systems for whole body vibration (ISO 2631).

8. Measurement of Whole-Body- Vibration Whole-Body-Vibration is usually measured from the seat or standing surface.

9. Exposure Time The exposure time is the daily time that a person is exposed to vibration in the course of a work period, usually expressed in units of hours or minutes.