Acoustic, Noise, Vibration & NVH Products worked example

Resonance Frequency Check at 68% signal confidence: a worked example

Suppose signal confidence falls to 68%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate natural frequency from completed vibration cycles, test time, and measurement confidence for quick resonance screening.

The inputs for this scenario

  • Measured vibration cycles: 3,600 cycles (held at the documented default)
  • Measurement time: 120 s (held at the documented default)
  • Signal confidence: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Raw frequency = measured vibration cycles รท measurement time.
  • Estimated resonance frequency works out to 20.4 Hz at these inputs, and this is the headline figure for the scenario.
  • Raw measured frequency works out to 30 Hz at these inputs.
  • Signal confidence works out to 68 % at these inputs.
  • Measurement time works out to 120 s at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where signal confidence sits at 95% and the headline result is 28.5 Hz, this scenario comes in 28.42% below the baseline at 20.4 Hz.
  • It divides counted vibration cycles by the measurement time to get raw frequency, then scales by signal confidence to give an estimated resonance frequency. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Estimated resonance frequency: 20.4 Hz (headline result)
  • Raw measured frequency: 30 Hz
  • Signal confidence: 68 %
  • Measurement time: 120 s

Run it with your numbers

  • To rerun this with your own numbers, open the live Resonance Frequency Check calculator, set signal confidence to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.