ISO 15186-1:2000

Overview

ISO 15186-1:2000 specifies a sound intensity method for laboratory measurement of sound insulation of building elements. It defines how to determine the intensity sound reduction index and the intensity element-normalized level difference as an alternative to traditional methods (ISO 140-3 and ISO 140-10). The standard is part of the ISO 15186 series and is intended for laboratory measurements where flanking transmission or small-element geometry can compromise conventional techniques.

Key topics and technical requirements

• Scope: Laboratory measurements of sound insulation in buildings and building elements using sound intensity.
• Measured quantities: Average sound pressure level in the source room and average normal sound intensity over a measurement surface on the receiving side.
• Measurement surface and distance: Use a measurement surface that fully encloses the test specimen (box-, hemispherical- or niche-shaped as applicable). Recommended measurement distance is typically 0.1–0.3 m; avoid distances < 0.1 m to prevent near-field effects.
• Instrumentation:
  • Intensity instrumentation must measure one-third-octave band intensity levels and comply with IEC 61043 (class 1).
  • Pressure-residual intensity index of the probe/analyser should be > 10 dB.
  • Sound pressure measurement equipment must meet ISO 140-3 requirements; source-room microphones should have a flat response in diffuse fields.
• Calibration and verification:
  • Verify IEC 61043 compliance at least annually (or every 2 years if using an intensity calibrator before each series).
  • Pre-test checks: warm-up, sound pressure calibration per IEC 60942, residual-intensity testing and (if available) sound-intensity calibrator checks.
• Result expressions & corrections:
  • Standard defines calculation of intensity-based R_I and D_I,n,e, and a modified intensity index R_I,M using an adaption term K (Annex B) to simulate traditional ISO 140-3 results.
• Quality checks: Use the surface pressure–intensity indicator (F) to ensure the field is appropriate (e.g., F ≥ 10 dB for reflecting specimens; ≥ 6 dB when the receiving side is sound-absorbing).

Applications and users

ISO 15186-1 is used by:

• Acoustic test laboratories and manufacturers of walls, windows, doors and small building elements
• Acoustical consultants validating laboratory sound insulation
• Test houses when flanking transmission invalidates ISO 140-3
• Standards bodies and specifiers needing an alternative, reproducible laboratory method for sound insulation testing

Practical advantages include reliable measurements for small elements and situations with high flanking transmission, with reproducibility equal to or better than ISO 140-3.

Related standards

• ISO 140-1 (laboratory facility requirements)
• ISO 140-3 / ISO 140-10 (traditional laboratory methods)
• ISO 717-1 (rating/weighting of indices)
• ISO 9614-1, IEC 60942, IEC 61043 (instrumentation and calibration)

Keywords: ISO 15186-1, acoustics, sound intensity, sound insulation, laboratory measurements, sound reduction index, element-normalized level difference, measurement surface, intensity probe.