ISO 9613-1-1993 PDF

Full title and description

ISO 9613-1:1993 — Acoustics — Attenuation of sound during propagation outdoors — Part 1: Calculation of the absorption of sound by the atmosphere. This part of ISO 9613 specifies an analytical method for calculating sound attenuation caused by atmospheric absorption for a variety of meteorological conditions and sound spectra (pure tones and banded/wideband sounds).

Abstract

Specifies formulae and tabulated attenuation coefficients to estimate atmospheric absorption losses for pure tones (nominally 50 Hz to 10 kHz) and gives methods for converting pure‑tone results to fractional‑octave or wideband spectra; includes extensions for ultrasonic frequencies and non‑standard pressures and guidance for atmospheres with vertical inhomogeneity.

General information

• Status: Published (International Standard, under periodic review; confirmed in 2021).
• Publication date: 3 June 1993.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 17.140.01 (Acoustic measurements and noise abatement in general).
• Edition / version: Edition 1 (1993).
• Number of pages: 26.

Scope

This part of ISO 9613 gives an analytical method to calculate attenuation of sound due solely to atmospheric absorption for outdoor propagation. It provides attenuation coefficients as functions of frequency, air temperature, relative humidity and (standard) pressure, tabulated values for common conditions, formulae for extended frequency and pressure ranges, and procedures to handle wideband spectra and fractional‑octave band analysis. The calculation assumes an atmosphere without significant fog or pollutants; other propagation effects (geometrical divergence, ground effect, screening, refraction) are covered in ISO 9613‑2.

Key topics and requirements

• Definition and computation of atmospheric absorption coefficients for pure tones (typical range 50 Hz–10 kHz) as functions of frequency, temperature (≈ −20 °C to +50 °C), relative humidity (≈ 10 % to 100 %) and standard atmospheric pressure.
• Tabulated attenuation coefficients for common meteorological conditions and guidance on accuracy and expected uncertainty ranges.
• Methods to convert pure‑tone attenuation to fractional‑octave and wideband spectra (midband approximation and an alternative spectrum‑integration method in annexes).
• Extensions for ultrasonic frequencies and for lower pressures (e.g., propagation from high altitudes) and notes on atmospheres with vertical inhomogeneity (informative annex).
• Normative references and links to related acoustic measurement standards used in conjunction with ISO 9613‑1 (examples: ISO 2533, ISO 266, relevant IEC/IEC‑type filter standards).

Typical use and users

Used by environmental acoustics consultants, noise modelers, regulatory agencies, researchers and engineers who need to predict or correct outdoor sound levels for atmospheric absorption (e.g., environmental impact assessments, industrial and traffic noise studies, acoustic scale modelling). Often applied together with ISO 9613‑2 (propagation algorithms) and national/local noise guidance.

Related standards

ISO 9613 is a multi‑part series; the main companion is ISO 9613‑2 (General method of calculation) which covers other propagation mechanisms (geometrical divergence, ground effects, screening, reflection) and is commonly used together with Part 1. Other referenced standards include ISO 2533 (standard atmosphere), ISO 266 (preferred frequencies / band definitions) and relevant IEC/ITU filter standards for octave/third‑octave analysis. Note that ISO 9613‑2 has seen later revisions (newer revisions published after 1996).

Keywords

atmospheric absorption, outdoor sound propagation, attenuation coefficient, environmental noise, acoustics, ISO 9613, fractional‑octave, wideband spectra, meteorological conditions

FAQ

Q: What is this standard?

A: ISO 9613‑1:1993 is an ISO International Standard that specifies methods to calculate the attenuation of sound caused by atmospheric absorption during outdoor propagation.

Q: What does it cover?

A: It covers formulae, tabulated attenuation coefficients and procedures for pure tones and wideband sounds (fractional‑octave bands), accounting for frequency, temperature, relative humidity and pressure; it does not cover ground or geometric propagation effects (see ISO 9613‑2).

Q: Who typically uses it?

A: Environmental acoustics consultants, noise modelers and researchers, governmental or regulatory bodies assessing outdoor noise, and engineers performing acoustic predictions or corrections for atmospheric absorption.

Q: Is it current or superseded?

A: ISO 9613‑1:1993 remains the published edition and was confirmed in ISO’s periodic review (confirmed in 2021); it is treated as the current version of Part 1 but is subject to ongoing ISO systematic review. For other parts of the series (e.g., ISO 9613‑2) later revisions have been issued.

Q: Is it part of a series?

A: Yes — ISO 9613 is a multi‑part standard on outdoor sound propagation. Part 1 treats atmospheric absorption; Part 2 covers the general method of calculation for outdoor propagation effects and is typically used alongside Part 1.

Q: What are the key keywords?

A: Atmospheric absorption, attenuation coefficient, outdoor sound propagation, environmental noise, fractional‑octave, A‑weighted level, meteorological conditions.