Overview
EN ISO 4871:2009 - "Acoustics - Declaration and verification of noise emission values of machinery and equipment (ISO 4871:1996)" provides guidance and requirements for declaring and verifying the noise emission of machinery and equipment. It defines what acoustical and product information should appear in technical documents and specifies a verification method for declared noise emission values. The standard replaces the earlier edition and supports compliance with the EU Machinery Directive (2006/42/EC) requirements for airborne sound emission.
Key topics and requirements
- Scope and purpose: Guidance on how manufacturers and suppliers should declare noise emission values so they are comparable, useful for purchasers, planners and authorities.
- Declared quantities: Focus on sound power level and emission sound pressure level at specified positions. Both single‑number and dual‑number declarations are addressed:
- Single-number declaration: L
- Dual-number declaration: L (value) and K (uncertainty); Ld = L + K corresponds to an upper limit or labelled value in accordance with ISO 7574.
- Presentation of data: Specifies acoustical information and product data to be included in technical documents, labels and specifications so users can compare products and assess compliance with noise limits.
- Verification: Defines a method to verify declared noise emission values (applicable to both sound power and emission sound pressure), enabling buyers and manufacturers to perform checks or include noise control in quality programs.
- Definitions and operating conditions: Clarifies terms such as machinery, family, batch, operating mode, emission and emission sound pressure to ensure consistent interpretation.
Practical applications
EN ISO 4871:2009 is intended for:
- Manufacturers and suppliers - to prepare standardized noise declarations, labels and technical data sheets.
- Test laboratories and acoustic engineers - to verify declared noise emission values and advise on measurement methods.
- Purchasers, machine‑room planners and safety officers - to compare noise levels of machinery when selecting equipment and planning workplaces.
- Regulators and conformity assessors - to demonstrate presumption of conformity with relevant requirements of the EU Machinery Directive (see Annex ZA).
Practical uses include equipment selection, workplace noise planning, compliance assessment, design decisions for noise control, and quality control of production batches.
Related standards
EN ISO 4871 references and complements other noise measurement and verification standards, including:
- ISO 3740 series (sound power determination)
- ISO 3743–3747, ISO 3744 (engineering and reverberation methods)
- ISO 9614 (sound intensity)
- ISO 11200–11204 (emission sound pressure methods)
- ISO 7574 series (statistical methods for declared values)
- ISO 11201 / 11202 / 11203 (emission at workstations and specified positions)
These related noise measurement standards define measurement procedures used to produce the noise data declared under EN ISO 4871:2009.
