Technical knowledge
When simultaneous noise and vibration measurement is useful
Sound and vibration are different quantities, but they may share a source or be linked by the transmission path. Measuring both on a common time base allows events to be compared and hypotheses to be tested.
Sound and vibration are different quantities, but they may share a source or be linked by the transmission path. Measuring both on a common time base allows events to be compared and hypotheses to be tested.
Typical situations
- Train, metro or heavy-traffic passages near buildings.
- Rotating equipment, ventilation, pumping and machinery mounted on structures.
- Construction, demolition, excavation and impact activities.
- Complaints of hum, pulsing or noise without a clear airborne source.
- Propagation tests between source, ground, structure and receiver.
The value of synchronisation
- It allows time histories to be overlaid and peaks or events to be compared.
- It helps compare delay, duration and repeatability.
- It supports selection of valid windows for spectral analysis.
- It reduces the risk of relating events that occurred at different times.
What correlation does not prove
- Two simultaneous signals may arise from a third common source.
- A component at the same frequency does not by itself prove the same origin.
- Causal attribution may require controlled shutdowns, further measurements or operating information.
- The strength of the conclusion depends on repeatability and signal quality.
Practical planning
- Define appropriate parameters, ranges and acquisition rates in both systems.
- Ensure synchronisation and a verifiable time reference.
- Document locations, sensor mounting, conditions and events.
- Preserve raw data or sufficient information for reanalysis.
This content is informative. Methods, criteria and framework should be defined for each specific case.