ISO 3740:2019 PDF

Overview

ISO 3740:2019 - Acoustics: Determination of sound power levels of noise sources provides guidance for selecting and using a set of twelve basic international standards that describe methods to determine sound power levels of machinery, equipment and products. The guidance applies to airborne sound and helps choose the most appropriate measurement method given the type of sound source, the measurement environment and the desired accuracy. ISO 3740:2019 is intended for preparing noise test codes and for noise emission testing where no specific code exists. It does not replace or add requirements to the individual basic test methods.

Key topics and requirements

• Scope and purpose
  • Guidance for selection among 12 basic standards (ISO 3741–3747, ISO 9614 series, ISO/TS 7849 series, etc.).
  • Applies only to airborne sound and typical industrial/product noise measurements.
• Measurement methods covered
  • Sound pressure-based methods (ISO 3741–3747).
  • Sound intensity methods (ISO 9614-1 to -3).
  • Vibration-based methods for structure-borne sources (ISO/TS 7849-1, -2).
  • High-frequency extensions (reference to ISO 9295 for up to 16 kHz).
• Selection criteria
  • Type and geometry of source, required accuracy/class (e.g., class 1/class 2), and practicability of laboratory vs in-situ testing.
  • Test environment considerations: laboratory rooms, special test rooms, hemi-anechoic checks and background noise limits.
• Quality and uncertainty
  • Guidance on achievable accuracy and reproducibility for each basic method.
  • Annexes include measurement uncertainty, acoustical test environments, and practical case studies.
• Limitations
  • Not covering sound energy level for transient single bursts (except noting limited use per ISO 12001).
  • Does not supersede specific machinery noise test codes.

Applications and users

ISO 3740:2019 is valuable for:

• Standards committees drafting noise test codes and product-specific noise standards.
• Manufacturers declaring or verifying product noise emission (sound power level).
• Accredited test laboratories selecting measurement methods and preparing test reports.
• Acoustic consultants and engineers performing noise emission assessments, workplace exposure predictions, and environmental noise modelling.
• Procurement and regulatory bodies comparing equipment noise performance or enforcing contract limits.

Practical uses include noise emission declarations, verification of declared levels, product comparisons, engineering noise control, and predicting worker or environmental noise exposure.

Related standards

• ISO 3741–3747 (sound pressure methods)
• ISO 9614-1 to -3 (sound intensity methods)
• ISO/TS 7849-1, -2 (vibration-based methods)
• ISO 9295 (high-frequency measurements)
• ISO 12001 (product noise labelling / test codes)

Keywords: ISO 3740:2019, sound power level, acoustics standard, noise emission testing, sound pressure, sound intensity, measurement uncertainty, laboratory acoustics, in‑situ measurements.