Overview
ISO 4871:1996 - "Acoustics - Declaration and verification of noise emission values of machinery and equipment" provides guidance for the clear declaration and statistical verification of machine noise emissions. Applicable to machinery and equipment, the standard defines what acoustic information manufacturers and suppliers should present in technical documents (sound power and emission sound pressure values), and specifies a verification method for declared noise emission values. ISO 4871:1996 replaces the first edition and complements measurement standards in the ISO 3740, ISO 9614 and ISO 11200 series.
Key topics and requirements
- Scope: Declaration and verification of noise emission values for machinery and equipment; guidance for presentation in technical documentation.
- Primary quantities:
- Sound power level (A‑weighted) - the preferred quantity to declare.
- Emission sound pressure level (A‑weighted at specified positions) - declared when required; peak C‑weighted values may also be used.
- Declaration formats:
- Single‑number: declared value L.
- Dual‑number: declared value L and uncertainty K; the upper limit Ld = L + K is also defined.
- Verification method:
- Statistical procedures (aligned with ISO 7574 series) for checking declared values - applicable to both sound power and emission sound pressure.
- Definitions and treatment of families, batches, operating modes, and measurement uncertainty.
- Documentation: specifies acoustical and product information to include in labels and technical literature to ensure comparability and transparency.
- Terminology and metrics: consistent definitions for emission, operating mode, work station, declared/measured values, and various standard deviations used in conformity assessment.
Applications and who uses it
- Manufacturers and suppliers: for product noise labeling, specification sheets and quality control (production verification).
- Testing laboratories and acoustical consultants: to verify manufacturer claims and undertake comparative tests.
- Buyers and procurement teams: to compare noise performance of competing machines during purchase decisions.
- Workplace planners and occupational health professionals: to assess equipment contributions to workplace noise and ensure compliance with exposure limits.
- Regulators and certification bodies: to evaluate conformity and to apply statistical acceptance criteria.
Related standards
Keywords: ISO 4871, noise emission, declaration and verification, acoustics standard, sound power level, emission sound pressure, machine noise, noise labeling, measurement uncertainty.