The RMS value - Why it is so important for vibration measurements

What is meant by the RMS value?

The RMS (Root Mean Square) value is a mathematical quantity used to describe the average power of a time-varying signal. In vibration measurement technology, it plays a key role in accurately capturing the "energetic effect" of a vibration—regardless of its fluctuations.

Formally, the RMS value describes the root mean square of a signal over a specific period of time. It thus provides a power-equivalent amplitude that is significantly more robust to short-term peaks than, for example, the maximum value.

Peak value vs. RMS value

• The peak value provides information about the peak load of a system

• The RMS value takes into account the continuous stress and provides information about the average energetic effect of the signal

This makes the RMS value particularly suitable for assessing the actual load , energy or power that a signal causes.

How is the RMS value calculated?

Mathematically, the RMS value is the root mean square of a signal:

For continuous signals:

For discrete data (such as from measuring instruments):

This means: You square all the values, calculate the mean – and then take the square root.

Conclusion

The RMS value is essential for the professional evaluation of vibrations – especially for long-term measurements and standard-compliant analysis. It provides a meaningful indicator for assessing the energetic impact of vibrations on people, buildings, or technical systems.