ISO standards 5349 and 2631
The hand-arm vibration is determined according to ISO 5349-1 directive, while whole body vibration is determined according to ISO 2631-1 directive. These international standards, which are in use in the Netherlands, describe the requirements for methods that determine the action and limit values. It is important to note that the values shown in the table are based on exposure during a working day (8 hours). If vibration occurs for less than this period, then this level is spread over a day. The table next to the body vibration A (8) daily values is also displayed the VDV (Vibration Dose Value). This parameter is used in the ISO 2631-1 standard, if there are high levels of peak occurrence in relation to the average vibration level. As previously mentioned in the Dutch health and safety policy, no limit values and action values are maintained for the VDV. Therefore, the final assessment of the vibration values will be based on the standard evaluation.
For the determination of the correct location for the vibration measurements, it is important to understand how the vibrations are analyzed. Vibrations are analyzed in accordance with the ISO 2631-1 standard for all three directions, of which two directions in the horizontal plane and one in the vertical plane.
These directions are shown in relation to the persons in Figure 1. Also clear from the figures below, vibration from the seat back surface can spread over the foot and enter the body. This study only considered the vibrations that enter the body through the seating surface of employees who are in different vehicles.