Generic Vibration Criteria


The vibration criterion (VC) curves, widely used and accepted throughout the world as a basis for evaluating facilities for vibration-sensitive instruments and tools and designing structures that will support vibration-sensitive equipment and process, were developed by Colin Gordon and his associates. Equipment operational problems that caused by vibration, can be prevented if environmental vibration complies with the vibration criterion curves appropriate to the equipment specific vibration criteria.

Vibration Criterion Curves (VC Curves)

The vibration criterion criteria takes the form of a set of one-third octave band velocity spectra labeled vibration criterion curves VC-A through VC-G, illustrated in Figure 1 and numerically defined in Table 1. The vibration is expressed in terms of its root-mean-square (rms) velocity.


Figure 1

What are Octave Bands?

Octave Bands provide a method of splitting the vibration levels into smaller segments known as Octaves, identifying different vibration levels across individual frequencies.

One third Octave Bands are mainly used environmental and noise control applications. Each Octave Band is further split into three called one third Octave Band, providing a more detailed view of vibration levels. The entire frequency range is divided into sets of frequencies known as bands. Each band represents a specific range of frequencies. As the band increases, the upper band frequency is twice the lower band frequency. ​


Table 1