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.
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.