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Acoustic and Vibration Standards Compliance - ANSI, IEC, ISO

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Overview

The NI Sound and Vibration Measurement Suite 6.0 and NI Sound and Vibration Toolkit 6.0 meet the following standards for measurement and analysis. All information is compiled from the User Manual, November 2007.

Table of Contents

  1. Overview of Standards
  2. Weighting Filters
  3. Octave Analysis
  4. Sound Level
  5. Certificates of Compliance

Overview of Standards

Weighting Filters

A-, B-, and C-Weighting Filters

  • ANSI S1.4-1983
  • ANSI S1.42-2001
  • IEC 61672-1:2002

Radiocommunications Weighting Filters

  • ITU-R 468-4
  • Dolby

Telecommunications Weighting Filters

  • ITU-T 0.41 (CCITT)
  • Bell System Technical Reference 41009 (C-message)

Human Vibration Weighting Filters

  • ISO 8041:2005 (E): Human Response to Vibration – Measuring Instrumentation 

Octave Analysis

  • ANSI S1.11-2004, class 1
  • IEC 1260:1995, class 1 (also IEC 61260)

Sound Level

  • ISO/IEC 61672-1:2002
  • IEC 651 (when used with appropriate microphone)
  • IEC 61260: 1995
  • ANSI S1.4

Weighting Filters

A-, B-, and C-Weighting Filters

ANSI Standards

When combined with any DSA device, the weighting filter used by the SVT A, B, C Weighting Filter (Fixed Rates) VI or designed by the SVT Weighting Filter VI complies with the following standards:

The SVT Weighting Filter VI accommodates any sample rate greater than 4 kHz and designs the filter coefficients to target the attenuation curves defined by the ANSI standards. Given the selected sampling frequency, compliance with a particular filter type, either Type 1 or Type 0, is ensured up to a specific frequency. This frequency is the maximum frequency within tolerances. Use the SVT Max Frequency Within Tolerances [ANSI] VI to determine the maximum frequency within tolerances. The SVT A, B, C Weighting Filter (Fixed Rates) VI supports the following sample rates:

4 kHz, 8 kHz, 10 kHz, 11.025 kHz, 12.8 kHz, 20 kHz, 22.05 kHz, 25.6 kHz, 40 kHz, 44.1 kHz, 48 kHz, 50 kHz, 51.2 kHz, 80 kHz, 96 kHz, 100 kHz, 102.4 kHz, 192 kHz, 200 kHz, 204.8 kHz, 500 kHz, 1 MHz

For all supported sample rates the VI achieves Type 0 compliance to the Nyquist frequency.

ISO/IEC Standard

Use the SVT A, B, or C Weighting Filter (Fixed Rates) VI or the SVT Weighting Filter VI to apply an A-, B-, or C-weighting filter to time-domain signals. When combined with any DSA device, the weighting filter used by the SVT A, B, or C Weighting Filter (Fixed Rates) VI or designed by the SVT Weighting Filter VI complies with:

  • IEC 61672-1:2002

The SVT Weighting Filter VI accommodates any sample rate greater than 4 kHz and designs the filter coefficients to target the attenuation curves defined by the IEC standards. Given the selected sampling frequency, compliance with a particular filter type, either Class 2 or Class 1, is ensured up to a specific frequency. This frequency is the maximum frequency within tolerances. Use the SVT Max Frequency Within Tolerances [IEC] VI to determine the maximum frequency within tolerances. The SVT A, B, C Weighting Filter (Fixed Rates) VI supports the following sample rates:

4 kHz, 8 kHz, 10 kHz, 11.025 kHz, 12.8 kHz, 20 kHz, 22.05 kHz, 25.6 kHz, 40 kHz, 44.1 kHz, 48 kHz, 50 kHz, 51.2 kHz, 80 kHz, 96 kHz, 100 kHz, 102.4 kHz, 192 kHz, 200 kHz, 204.8 kHz, 500 kHz, 1 MHz 

For all supported sample rates the VI achieves Class 1 compliance to the Nyquist frequency.

Radiocommunications Weighting Filters

 

ITU-R 468-4 and Dolby

When combined with any DSA device, the weighting filter used by the SVT Radiocommunications Weighting Filter (Fixed Rates) VI complies with the ITU-R 468-4 standard. The SVT Radiocommunications Weighting Filter (Fixed Rates) VI accommodates the following sample rates:

20 kHz, 22.05 kHz, 25.6 kHz, 40 kHz, 44.1 kHz, 48 kHz, 50 kHz, 51.2 kHz, 80 kHz, 96 kHz, 100 kHz, 102.4 kHz, 192 kHz, 200 kHz, 204.8 kHz, 500 kHz, 1 MHz

For all supported sample rates, the VI achieves compliance to the Nyquist frequency.

Telecommunications Weighting Filters

When combined with any DSA device, the weighting filter used by the SVT Telecommunications Weighting Filter (Fixed Rates) VI complies with the following standard and reference:

  • ITU-T 0.41 (CCITT)
  • Bell System Technical Reference 41009 (C-message)

The SVT Telecommunications Weighting Filter (Fixed Rates) VI supports the following sample rates:

4 kHz, 8 kHz, 10 kHz, 11.025 kHz, 12.8 kHz, 20 kHz, 22.05 kHz, 25.6 kHz, 40 kHz, 44.1 kHz, 48 kHz, 50 kHz, 51.2 kHz, 80 kHz, 96 kHz, 100 kHz, 102.4 kHz, 192 kHz, 200 kHz, 204.8 kHz, 500 kHz, 1 MHz

For all supported sample rates, the VI achieves compliance to the Nyquist frequency.

Human Vibration Weighting Filters

When combined with any DSA device, the human vibration weighting filters that the Sound and Vibration Measurement Suite provides comply with ISO 8041:2005 (E): Human Response to Vibration – Measuring Instrumentation.

The Sound and Vibration Measurement Suite provides the following weighting filters that you can apply to human vibration signals:

  • Wb—Weighting for vertical whole-body vibration, z–axis, seated, standing or recumbent person, based on ISO 2631–4.
  • Wc—Weighting for horizontal whole-body vibration, x–axis, seat back, seated person, based on ISO 2631-1.
  • Wd—Weighting for horizontal whole-body vibration, x– or y–axis, seated, standing or recumbent person, based on ISO 2631-1.
  • We—Weighting for rotational whole-body vibration, all directions, seated person, based on ISO 2631-1.
  • Wf—Weighting for vertical whole-body vibration, z–axis motion sickness, seated or standing person, based on ISO 2631-1.
  • Wh—Weighting for hand-arm vibration, all directions, based on ISO 5349-1.
  • Wj—Weighting for vertical head vibration, x–axis recumbent person, based on ISO 2631-1.
  • Wk—Weighting for vertical whole-body vibration, z–axis seated, standing or recumbent person, based on ISO 2631-1.
  • Wm—Weighting for whole-body vibration in buildings, all directions, based on ISO 2631-2.

Octave Analysis

Overview

The Octave Analysis VIs can accommodate any sampling frequency and any number of fractional-octave bands. These VIs offer compliance with the following standards:
· ANSI S1.11-2004, class 1
· IEC 1260:1995, class 1

Midband Frequencies 

According to the IEC 1260:1995 and the ANSI S1.11:2004 standards, the midband frequency, or center, frequency of the bandpass filter is defined by the following equations:
fi = 1000 * 2ib for 1/N octave filters when N is odd

fi = 1000 * 2(i+1)b/2 for 1/N octave filters when N is even

where
fi is the center frequency of the ith band-pass filter expressed in hertz.
i is an integer when i = 0, f0 = 1 kHz, which is the reference frequency for the audio range.
b is the bandwidth designator and equals 1 for octave, 1/3 for 1/3 octave, 1/6 for 1/6 octave, 1/12 for 1/12 octave, and 1/24 for 1/24 octave.

Nominal Frequencies

The exact midband frequencies are used to design the filters for fractional-octave analysis. However, all the Octave Analysis VIs return the nominal midband frequencies, also called the preferred frequencies. In the case of octave and 1/3 octave analyses, the nominal frequencies are calculated in accordance with the ANSI and IEC standards. In the case of 1/6, 1/12, and 1/24 octave analyses, the nominal frequencies are calculated in accordance with the Annex A (informative) of the IEC 1260:1995 and the ANSI S1.11:2004 standards.

Compliance with ANSI and IEC Standards

When combined with any National Instruments DSA device, the appropriate microphone, and proper signal conditioning, the filters produced by the Octave Analysis VIs comply with the following standards:

  • ANSI S1.11-2004: Specification for octave-band and fractional-octave-band analog and digital filters, class 1
  • IEC 1260 (1995 - 07): Electroacoustics - Octave-band and fractional-octave-band filters, class 1

For octave filters, choose a sampling frequency at least three times the exact center frequency of the highest frequency band. For fractional-octave filters, choose a sampling frequency at least 2.5 times the exact center frequency of the highest frequency band. 

Sound Level

When combined with any National Instruments DSA device, the appropriate microphone, and proper signal conditioning, the Sound Level VIs are compliant with the ISO/IEC 61672-1:2002 standard.

IEC 651 defines four classes of accuracy for a sound level meter, with Type 0 being the most accurate and Type 3 being the least accurate. Type 1 sound level meters are the most widely used sound level meters in practice. Detailed requirements for a sound level meters are given in ANSI S1.4 (SVT compliant) and IEC Publications 651 and 804.

National Instruments dynamic signal acquisition boards combined with the NI LabVIEW Sound and Vibration Toolkit, have been tested and found compliant with several ANSI and IEC standards including the requirements for a class 1 instrument specified in IEC 61672-1: 2002. The filters used meet the requirements for a class 1 instrument specified in IEC 61260: 1995.

For a complete system, a suitable microphone compatible with ANSI S1.4 or IEC 651 requirements for a Type 1 precision microphone needs to be specified.

Certificates of Compliance

See download section.

Related Links:
Measurement Encyclopedia - Acoustic Standards

Downloads

octave_analysis_cert_0508.pdf

human_vib_weight_cert_0508.pdf

weighting_filters_cert_0508.pdf

slm_cert_0508.pdf

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