ISO 16251-1:2014

Overview

ISO 16251-1:2014 - "Acoustics - Laboratory measurement of the reduction of transmitted impact noise by floor coverings on a small floor mock-up - Part 1: Heavyweight compact floor" - specifies a laboratory method to determine the improvement of impact sound insulation provided by soft, flexible floor coverings (e.g., carpets, PVC, linoleum) installed on a standardized small concrete mock-up. The method measures structure-borne vibration (acceleration) induced by a standard tapping machine and gives comparable results to the larger ISO 10140 series within the stated uncertainty and application limits. This is a cost‑effective test approach for manufacturers and test labs that cannot use full ISO 10140 room facilities.

Key topics and technical requirements

• Scope limitation: Applicable to locally reacting floor coverings (category I per ISO 10140‑1), where impact energy is transmitted mainly near the hammer contact area. Not intended for laminated or non‑flexible floorings where specimen size affects results.
• Test mock‑up: Concrete slab sized (120 ± 5) cm × (80 ± 5) cm × (20 ± 1) cm, softly supported on elastic bearings; vertical resonance below 20 Hz; flatness ±1 mm.
• Impact source: Standard tapping machine complying with ISO 10140‑5.
• Sensors & instrumentation: Accelerometers fixed to the lower slab surface; measurement chain (filters, amplifiers, meters) meeting relevant standards (IEC 61672‑1 class 1 equivalence with accelerometer, IEC 61260 class 1 filters); vibration calibration per ISO 16063.
• Measurement geometry: At least four accelerometer positions (randomly distributed avoiding symmetry) and at least two tapping machine positions; hammer positions ≥10 cm from edges.
• Frequency bands: One‑third‑octave bands from 100 Hz to 5 000 Hz (optionally 50–80 Hz for low‑frequency data).
• Procedure & evaluation: Three measurement cycles - with specimen, without specimen, and background noise. Background correction rules provided; compute level differences per accelerometer/tapping position and average to obtain the improvement ΔL (dB).
• Reporting: Record environmental conditions, calibration, measurement data and uncertainty.

Applications

• Product acoustic testing for floor covering manufacturers (SMEs needing lower‑cost lab methods).
• Independent acoustic test laboratories and certification bodies performing product declarations.
• Acoustic consultants, building designers and specifiers evaluating impact sound mitigation performance for flooring choices.
• Research and development of soft floor coverings and quality control in production.

Related standards

• ISO 10140 series (laboratory measurement of sound insulation)
• ISO 10140‑1 (reference categories)
• ISO 10140‑5 (tapping machine)
• ISO 717‑2 (rating of impact sound insulation)
• ISO 16063 (vibration transducer calibration)
• IEC 61672‑1 and IEC 61260 (measurement equipment and filters)

Keywords: ISO 16251-1:2014, impact sound, floor coverings, laboratory measurement, tapping machine, accelerometer, concrete mock-up, ISO 10140, locally reacting, acoustic testing.