Manfred Weber
Metra Mess- und Frequenztechnik in Radebeul e.K.
PC Vibration Measurement System VibroMetra

VM-OCT (+)

In addition to the calculation of overall values within a certain frequency range and frequency analysis of amplitudes at discrete frequencies vibrations can also be analyzed in defined frequency intervals, so called octave bands or fractions of them. Octave analysis is typically performed with logarithmic frequency scale. The corner frequencies of an octave band have always a ratio of 2:1. Hence with a logarithmic frequency axis octave bands appear with fixed width. 
Octave band analysis is a mix of overall values and frequency analysis. It shows the vibration values of different frequency intervals at a glance.
There are mainly two fields of application for this type of measurement:
  •  Acoustic measurements: The frequency range of 16 .. 16000 Hz is used. Octaves and fractions of 1/3 and 1/6 octaves are analyzed.
  • Vibration monitoring of very sensitive equipment: Mainly 1/3 octave bands are measured. The frequency range of 1 (4) .. 80 Hz is commonly used in the semiconductor industry for monitoring the production environment.
VM-OCT can be used for the measurement of so called Vibration Criteria (VC lines), Nano lines and for acoustic measurements with octave, 1/3 octave and 1/6 octave bands.
VibroMetra uses octave filters in compliance with EN 61260.