Overview
EN ISO 11546-1:2009 (ISO 11546-1:1995) specifies laboratory methods for determining the sound insulation performance (insertion loss) of small machine enclosures under controlled conditions for declaration purposes. It applies to a total enclosure only (not individual panels) and is intended primarily for freestanding enclosures with volumes less than 2 m³. When the actual sound source is used, larger volumes may be accommodated subject to the referenced standards’ limits. The standard was adopted by CEN and supports conformity with relevant EU machinery directives.
Key topics and requirements
- Measurement scope
- Determination of insertion loss expressed as reductions in sound power or sound pressure levels.
- Laboratory conditions that conform to referenced ISO/IEC standards.
- Choice of measurement method
- Methods using the actual sound source (machine inside the enclosure).
- Methods for enclosures without the actual source: reciprocity method and artificial sound source method.
- Limitations: reciprocity and artificial source methods are generally limited to enclosures ≤ 2 m³ and are not suitable for close‑fitting enclosures.
- Instrumentation and procedures
- Instrumentation and test environment aligned with series standards (ISO 3740, ISO 9614, ISO 11200 and related IEC standards for meters, filters and calibrators).
- Requirements for measuring sound power, sound pressure at specified positions, and environmental corrections when needed.
- Data handling
- Procedures for weighted sound power insulation, estimation of noise insulation for a specific noise spectrum, and calculation of measurement uncertainty.
- Detailed lists of information to be recorded and reported about the test object, conditions, instrumentation and acoustical data.
- Annexes
- Practical aids such as an artificial sound source description, example source spectrum, and a worked example for estimating insulation for a given spectrum.
Applications
- Declaring the acoustic performance of machine enclosures for product datasheets, procurement, and regulatory compliance.
- Designing and validating noise‑control enclosures for industrial machinery, HVAC units and small equipment.
- Comparing enclosure concepts during product development to quantify expected noise reduction (insertion loss).
Who uses this standard
- Acoustic consultants and test laboratories performing laboratory measurements.
- Product designers and R&D teams for machinery and noise control products.
- Compliance and certification bodies assessing conformity with EU machinery directives and noise‑abatement requirements.
Related standards
Keywords: EN ISO 11546-1:2009, sound insulation, acoustics, machine enclosures, laboratory measurements, insertion loss, reciprocity method, artificial sound source, sound power, sound pressure.