HAV - Calculating the level of exposure

The current legislation establishes that the level of exposure to vibration shall be assessed by the calculation of the frequency-weighted equivalent acceleration value over an eight-hour reference period. This can be calculated by using the following formula:

where:

T_e :                        Total daily duration of vibration exposure (hours)
a_v                         Acceleration value resulting from the vectorial sum of the components measured on the orthogonal axes:

If the worker is exposed to different vibration values, as in the case of  the usage of several machines in a working day, the daily vibration exposure A(8) expressed as m/s2, will be calculated as follows:

where:

a²_vi : vectorial sum of the frequency-weighted acceleration for the i-th operation
T_i : Exposure duration for the i-th operation (hours)