Spider DSA User’s Manual
361
Figure 220. Full octave filter shape.
The proportional bandwidth display is very useful for analyzing a variety of
natural systems such as the human response to noise and vibration. Many
mechanical systems exhibit behavior that is best characterized by proportional
bandwidth analysis.
To gain finer frequency resolution, the frequency range can be divided into
proportional spacings that are a fraction of an octave. For example, with 1/3
octave spacing, there are 3 SDOF filters per octave. In general, for 1/N fraction
octave, there are N band pass filters per octave such that:
Where 1/N is called the fractional octave number and the reference frequency is
simply the lowest desired frequency, f
c1
. With the reference frequency and
fractional octave number established, the frequency distribution over the whole
frequency range is determined.
Measured Signals in SRS
The measurement quantities available to the Spider SRS test are: time stream of
each channel (raw data), block captured time signals and three SRS’s of each
channel.
To Next Page
Loading...