What IEC 61672-1 Covers

IEC 61672-1:2013 "Electroacoustics — Sound level meters — Part 1: Specifications" is the primary international standard governing the design and performance of sound level meters. Published by the International Electrotechnical Commission, it defines the electroacoustic characteristics that instruments must meet to be classified as conforming sound level meters.

The standard applies to instruments that measure sound pressure level with standardized frequency weightings (A, C, Z) and time weightings (Fast, Slow, Impulse). It covers both conventional and integrating-averaging sound level meters in a single unified document.

Class 1 and Class 2 Instruments (Clause 4)

Clause 4 defines two performance categories. Class 1 instruments have tighter tolerances (typically ±1.1 dB at reference frequency) and are required for precision measurements, laboratory work, and legal enforcement. Class 2 instruments have wider tolerances (typically ±1.4 dB) suitable for general-purpose field surveys and screening measurements.

The class designation affects every specification in the standard — frequency weighting tolerance, linearity range, detector response, and directional characteristics all have different limits depending on class.

Measurements Within Scope

IEC 61672-1 covers the following measurement quantities:

Time-weighted sound pressure level (LAF, LAS, LAI, LCF, LCS, LZF, LZS)
Time-average sound pressure level (LAeq, LCeq, LZeq)
Peak sound pressure level (LCpeak, LZpeak)
Sound exposure level (LAE, LCE)

The standard does not cover octave-band or fractional-octave-band analysis (see IEC 61260-1), nor does it address measurement procedures for specific applications.

Relationship to Other Standards

IEC 61672 is a multi-part standard. Part 1 covers specifications, Part 2 covers pattern evaluation tests, and Part 3 covers periodic verification tests. Together they replaced four older standards: IEC 60651 (conventional SLMs), IEC 60804 (integrating-averaging SLMs), IEC 61672-1:2002, and IEC 61672-2:2003.

For field calibration requirements, see IEC 61672-1 Calibration. For the US equivalent, see ANSI S1.4.

Practical Relevance

Whether you are conducting SPL measurements for noise ordinance compliance, occupational health assessments under OSHA 1910.95, or environmental noise monitoring per ISO 1996, the underlying sound level meter must conform to IEC 61672-1. SonaVyx implements IEC 61672-1 Class 2 equivalent processing including A, C, and Z frequency weightings and all three time weightings.