Vibrations originate in in- and out-movements of machines and rotating machines and machine components, for example of pistons, compressors, rotors, shafts and rollers, as well as gearboxes and pumps. The amplitude and the frequencies depend on the natural frequencies and stiffness. Additional shocks that are caused by damage to individual components are additionally provoking vibrations on machines. Based on their amplitudes and frequencies, machine and component faults can be detected and localized, for example: unbalance, rolling bearing damage or misalignment.

In vibration analysis, we record and analyze the vibrations with accelerometers, vibration velocity sensors or vibration displacement sensors.

There are various analysis options for recording and documenting vibrations on machines. These are in particular the vibration level and the band-limited oscillation level. Frequency analysis and envelope analysis methods are used to diagnose vibrations. International standards include ISO 10816, ISO 20816, VDI 3832.

A frequency analysis can be calculated narrow-band as FFT analysis or clearly laid out as as a third-octave and octave analysis. In frequency analysis, a basic distinction is made between two methods: third-octave and octave analysis or FFT analysis.

Enveloping curve analysis is a method to separate (demodulate) amplitude modulated signals into carrier and damage frequencies. Therefore, it is used for the detection of damage, especially in rolling bearings. Here, each bearing has an individual fingerprint. With the help of an FFT analysis and the knowledge of the mechanic structure of the bearing, the damaging frequencies can be separated according to inner ring, outer ring and rolling element.

Human vibrations are mechanical vibrations that are transmitted to the human body. Typical machines for this are power saws, angle grinders, hammer drills, pneumatic hammers and demolition hammers. The impact of these vibrations on bones and joints leads to circulatory disorders and nerve damage, and in the long term can lead to occupational diseases such as white finger disease. A distinction is made between 2 main groups: Whole-body vibrations and hand-arm vibrations in the X, Y and Z directions.

Mostly with a triax vibration sensor or a seat vibration sensor representing vibration acceleration or vibration velocity.

If we consider the human being as a mechanical model, subdividing it into spring-mass systems, each body-part has a a different natural frequency for, which can be damaged by continuous loading. The vibration load depends mainly on the frequency, the amplitude and the applied pressure force as well as the duration of the impact. International standards include EN 1032, ISO 2631-x, ISO 28927, ISO 5349, ISO 8041 and VDI 2057.