Fractional-octave-band filter

Signals filtration program

Each channel of Signals filtration program allows to use octave-band and fractional-octave-band filters. The filters are implemented in compliance with the applicable requirements (IEC 61260:1995).

The essence of octave-band filtration is the separation of the controlled signal into octave frequency bands. Octave frequency band (an octave) is a frequency band having relation of upper band-edge to the lower band-edge equal to 2/1. Hence, the octave-band filters are used to divide the entire controlled frequency range into a certain number of octaves to be used for further processing.

The program Signals filtration has the following functions:

  • octave-band filter with precise central frequencies: 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, 8000 Hz;
  • 1/3-octave-band filter with accurate central frequencies: 315 Hz, 400 Hz, 500 Hz, 630 Hz, 800 Hz, 1000 Hz, 1250 Hz, 1600 Hz, 2000 Hz, 2500 Hz, 3150 Hz, 4000 Hz, 5000 Hz, 6300 Hz, 8000 Hz, 10000 Hz.

Фильтрация сигналов - Долеоктавная фильтрация

Спектр исходного сигнала (белый шум)

Source signal spectrum (white noise)

Спектр сигнала после долеоктавной фильтрации на центральной частоте 500 Гц

Signal spectrum: 1/3-fractional-octave-band filter at the central frequency of 500 Hz