ISO 11546-2:1995

ISO 11546-2:1995 - Acoustics: Determination of sound insulation performances of enclosures - Part 2: Measurements in situ (for acceptance and verification purposes)
Organization: ISO

Overview

ISO 11546-2:1995 specifies in situ (on-site) measurement methods for determining the sound insulation performance (insertion loss) of total machine enclosures. It is intended for acceptance and verification of enclosures as installed and applies to whole enclosures (not individual panels). The standard describes procedures using either the actual sound source (the machine) or an artificial sound source, and gives guidance on instrumentation, test environments, uncertainty and reporting.

Keywords: ISO 11546-2, acoustics, sound insulation, in situ measurements, machine enclosures, insertion loss

Key topics and technical requirements

• Scope and applicability
  • Applies only to total enclosures (not individual doors, panels or silencers).
  • Measurement results depend on installation and workmanship.
• Measurement quantities
  • Sound power insulation (Dw), A-weighted sound power insulation (DwA), sound pressure insulation (Dp), and A-weighted equivalents (DpA).
  • Single-number weighted indices (reference to ISO 717-1 method with Dw substituted as required).
• Measurement methods
  • Methods using the actual sound source when practicable.
  • Artificial sound source methods when the machine cannot operate or identical conditions cannot be ensured.
  • Survey and engineering methods for sound power or sound pressure depending on environment (e.g., hard-walled test room, outdoors, reverberant field).
• Instrumentation and calibration
  • Use of class/type 1 sound level meters and filters for octave/one‑third-octave measurements; integrating-averaging meters recommended.
  • Pre- and post-measurement calibration using an acoustic calibrator (type 1, ±0.3 dB).
• Practical measurement considerations
  • Leak ratio and fill ratio definitions; recommended low leak ratio (ideally < ~2% when using artificial source) and sound-absorbing interior surfaces.
  • Guidance on uncertainty, information to be recorded and reported (test object, conditions, instrumentation, acoustical data).
• Supporting annexes
  • Annex A (artificial source), B (example spectrum), C (applicability of environments), D (estimating insulation for specific spectra), E (bibliography).

Practical applications

• Acceptance testing and verification of noise-reducing enclosures for industrial machinery.
• On-site evaluation of enclosure effectiveness to demonstrate regulatory or contract compliance.
• Estimating A-weighted noise reduction for specific machine spectra when lab data are not available.

Who should use it

• Acoustical consultants and test engineers performing field noise measurements.
• OEMs and facility engineers validating enclosure performance after installation.
• Compliance officers verifying noise control measures for occupational or environmental noise limits.

Related standards

• ISO 11546-1 (laboratory measurements / declaration purposes)
• ISO 3740, ISO 3743, ISO 3744, ISO 3746, ISO 9614, ISO 11200, ISO 11201, ISO 11202, ISO 11204 (referred measurement methods)
• IEC standards for sound level meters and filters (e.g., IEC 651/804/942/1260)

Use ISO 11546-2 when you need reliable, on-site acoustic verification of complete machine enclosures and documented, repeatable test procedures for acceptance and verification.