A discussion on comparing alternative vibration measures with frequency-weighted accelerations defined in ISO standards.
Dong-RG; Wu-JZ; Welcome-DE; McDowell-TW
J Sound Vib 2008 Nov; 317(3-5):1042-1050
It is invalid to perform a direct comparison of an alternative vibration measure and ISO-frequency-weighted acceleration if the alternative measure cannot be considered as a linear function of the acceleration. This is the major problem in the first two comparison methods evaluated in this discussion. It is acceptable to use a third method, correlation analysis, to examine the relationship between the alternative measure and the ISO-weighted acceleration. A fourth method, frequency-weighting derivation and comparison, is the most appropriate method to determine the frequency dependency of the alternative measure and to identify its relationship to ISO weighting. The combination of correlation analysis and derived frequency weighting may provide a comprehensive analysis and understanding of an alternative method. Each of the vibration exposure measures can generally be divided into two components: (i) the quantification of raw vibration inputs to the hand or body; and (ii) vibration frequency weighting. Although there may be some interaction between these two components [9,25], each represents a different aspect of the vibration exposure assessment. While methods for measuring raw vibration inputs continue to evolve, the determination of appropriate frequency weighting remains a major issue and further studies are certainly required. The generalized frequency-weighting method outlined in this discussion provides a tool for deriving frequency weightings for various biodynamic measures and for identifying similarities and differences among them. This frequency-weighting method is also useful for investigating the influences of various factors on each measure. Frequency weightings can also be modified to take into account any such factors.
Musculoskeletal-system; Musculoskeletal-system-disorders; Vibration-effects; Vibration-exposure; Power-tools; Vibration-disease
Ren G. Dong, Engineering & Control Technology Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Road, MS L-2027, Morgantown, WV 26505
Journal of Sound and Vibration