Human vibration

Vibration transmitted to a person is evaluated with a measurement chain deliberately parallel to a sound level meter’s: the acceleration is frequency-weighted to reflect how the body responds at each frequency, reduced to a weighted r.m.s. value or a dose, combined across axes, and normalised to a daily exposure that regulation can act on. The two pages of this section cover the general chain and the special case that breaks it.

Human Vibration is the general chain. It covers the whole-body and hand-arm frequency weightings of ISO 8041-1, the weighted r.m.s. acceleration and the running and dose measures of ISO 2631-1 (MTVV, VDV, MSDV, crest factor) that flag shocks a plain r.m.s. would hide, vibration in buildings per ISO 2631-2, the hand-arm vibration total value and daily exposure A(8) of ISO 5349-1/-2, and the exposure action and limit values of Directive 2002/44/EC that make A(8) legally meaningful.

Multiple-shock whole-body vibration (ISO 2631-5) handles exposures the r.m.s. philosophy underestimates: repeated mechanical shocks from off-road vehicles, high-speed craft or earth-moving machinery, which load the lumbar spine far beyond what their energy average suggests. ISO 2631-5:2018 models the seat-to-spine transfer explicitly, accumulates a dose from the response peaks, and converts it into compressive stress on the vertebral endplates and a probability of lumbar injury over a working life.

Use ISO 2631-1 metrics first; when the crest factor or the VDV warns that shocks dominate, the ISO 2631-5 model is the dedicated follow-up. The measurement front-end (weighting filters, band analysis) is shared with the core signal analysis section.

Pages in this section

• Human Vibration: ISO 8041-1 weightings, ISO 2631-1 r.m.s. and dose measures, ISO 5349 daily exposure A(8) and the Directive 2002/44/EC values.
• Multiple-shock whole-body vibration (ISO 2631-5): the spinal-response model, acceleration dose and probability of lumbar injury.