building.floor_covering_improvement

Impact-sound improvement of floor coverings on a small mock-up (ISO 16251-1:2014).

Laboratory method for the improvement of impact sound insulation ΔL of a soft, locally-reacting floor covering (carpet, PVC, linoleum; ISO 10140-1 Annex H category I) laid on a small concrete mock-up plate and excited by a standard tapping machine. The two rooms of the ISO 10140 series are removed and the floor is replaced by a softly-supported concrete plate; instead of the receiving-room sound pressure level, the structure-borne acceleration level on the underside of the plate is measured with and without the covering. For locally-reacting coverings this acceleration-level difference equals the ISO 10140 impact sound reduction (Clause 4).

Acceleration level (Formula (1)). La = 10 lg[(1/Tm) ∫ a(t)²/a0² dt] dB, with the reference acceleration a0 = 1e-6 m/s², i.e. La = 10 lg(⟨a²⟩/a0²).

Background correction (Formula (2)). Each measured level L' is corrected against the background Lb per accelerometer position, by the margin L' − Lb: unchanged for ≥ 15 dB; energy subtraction 10 lg(10^(L'/10) − 10^(Lb/10)) for 6 ≤ margin < 15 dB; and the fixed L' − 1,3 dB limit for < 6 dB. Bands hitting the 1,3 dB limit are flagged as the limit of measurement (reported as > ΔL). This differs from the ISO 10140-4 correction (phonometry.background_correction) only at exactly margin = 6 dB.

Improvement (Formulae (3)/(4)). The per-position difference is ΔLt,a = L0,t,a − L1,t,a (0 = bare plate, 1 = specimen) and the improvement is their arithmetic mean over all tapping-machine (t) and accelerometer (a) positions, ΔL = (1/(t·a)) Σt Σa ΔLt,a.

Octave bands (Formula (5)). ΔLoct = −10 lg[(1/3) Σ 10^(−ΔL_n/10)] dB from the three one-third-octave values in each octave.

Weighted improvement. ΔLw is the ISO 717-2 weighted reduction of impact sound pressure level (Clause 6.5), computed with the heavyweight reference floor via phonometry.weighted_impact_improvement on the 16 rating bands 100 Hz to 3150 Hz; a wider clause 6.3 spectrum (18 bands 100-5000 Hz, optionally extended to 50 Hz) is rated on that sub-range. The statement of results (Clause 8 e)) also carries the spectrum adaptation term CI,Δ (ISO 717-2:2020 Formula (A.4)) via phonometry.impact_improvement_adaptation_term.

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acceleration_level

acceleration_level(
    acceleration: float | Sequence[float] | np.ndarray,
    *,
    reference: float = 1e-06,
) -> np.ndarray

Vibratory acceleration level La (ISO 16251-1 Formula (1)).

La = 10 lg(a_rms² / a0²) = 20 lg(a_rms / a0) dB.

Parameters

Name	Description
acceleration	RMS acceleration a_rms per band, in m/s² (> 0).
reference	Reference acceleration a0, in m/s² (default 1e-6).

Returns: The acceleration level La per band, in dB.

Raises

Exception	When
ValueError	Non-finite or non-positive acceleration, or a non-positive reference.

background_corrected_level

background_corrected_level(
    signal_and_background: float | Sequence[float] | np.ndarray,
    background: float | Sequence[float] | np.ndarray,
) -> tuple[np.ndarray, np.ndarray]

Correct a measured level for background noise (ISO 16251-1 Formula (2)).

Parameters

Name	Description
signal_and_background	Measured level L' (with background) per band, in dB.
background	Background-noise level Lb per band, in dB.

Returns: (corrected, limited): the corrected levels L per band, in dB, and a boolean mask of bands at the 1,3 dB limit of measurement (report as > ΔL).

Raises

Exception	When
ValueError	Mismatched shapes or non-finite values.

FloorCoveringImprovementResult

FloorCoveringImprovementResult(
    frequencies: np.ndarray,
    improvement: np.ndarray,
    limited: np.ndarray,
    delta_lw: int | None,
    ci_delta: int | None = None,
)

Impact-sound improvement of a floor covering (ISO 16251-1).

Attributes

Name	Description
frequencies	One-third-octave band centre frequencies, in Hz.
improvement	Improvement of impact sound insulation ΔL per band, in dB.
limited	Per-band boolean mask of bands at the 1,3 dB limit of measurement (reported as > ΔL); all False when no background correction was applied.
delta_lw	Weighted improvement ΔLw (ISO 717-2), in dB, or None when the spectrum does not contain the 16 one-third-octave rating bands 100-3150 Hz. A wider clause 6.3 spectrum (e.g. the 18 bands 100-5000 Hz, optionally extended down to 50 Hz) is rated on its 100-3150 Hz sub-range.
ci_delta	Spectrum adaptation term CI,Δ (ISO 717-2:2020 Formula (A.4); required in the ISO 16251-1 Clause 8 e) statement of results), in dB, or None when delta_lw is None.

FloorCoveringImprovementResult.octave_bands()

FloorCoveringImprovementResult.octave_bands() -> tuple[np.ndarray, np.ndarray]

Return (octave_freqs, ΔLoct) via Formula (5) (needs 16 1/3-oct bands).

FloorCoveringImprovementResult.plot()

FloorCoveringImprovementResult.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Plot the improvement spectrum ΔL (with ΔLw when available).

Requires matplotlib (pip install phonometry[plot]); returns the Axes.

FloorCoveringImprovementResult.report()

FloorCoveringImprovementResult.report(
    path: str,
    *,
    metadata: ReportMetadata | None = None,
    engine: str = 'reportlab',
    verbose: bool = False,
    language: str = 'en',
) -> str

Render an ISO 16251-1 impact-improvement test-report fiche to a PDF.

Writes a one-page accredited report (BS EN ISO 16251-1:2014, the small-mock-up laboratory method for the reduction of transmitted impact sound by soft floor coverings): the standard-basis line, an optional metadata header block, a two-panel body with the per-band table (frequency and the reduction of impact sound pressure level ΔL, bands at the 1,3 dB limit of measurement prefixed >) beside the ΔL(f) improvement curve, a boxed single-number weighted improvement ΔLw (CI,Δ) (ISO 717-2, the Clause 8 e) statement of results; a characterisation headline replaces it when the spectrum lacks the 16 rating bands 100-3150 Hz), an optional verdict row and a footer.

Parameters

Name	Description
path	Destination path of the PDF file.
metadata	Optional ReportMetadata; None produces a body-and-disclaimer fiche whose header shows only the measured frequency range. The applicable descriptive fields are client, manufacturer, specimen (the floor covering under test), mounting, mass_per_area, test_room, test_date, temperature, pressure, measurement_standard, laboratory, operator, report_id and notes. The bare reference floor is the standardised heavyweight floor of ISO 717-2:2020 Table 4, fixed by the standard. When requirement is set the fiche adds a verdict row (a higher weighted improvement is better, so the result passes at or above the requirement).
engine	Rendering back end; only "reportlab" is supported.
verbose	When True, the per-band table gains the reference-floor-with-covering column Ln,r = Ln,r,0 - ΔL (ISO 717-2:2020 Formula (1)), the derivation basis of ΔLw, when the spectrum is exactly the 16 rating bands 100-3150 Hz.
language	Fiche language: "en" (default, English, decimal point) or "es" (Spanish, decimal comma).

Returns: The written path as a str.

Raises

Exception	When
ValueError	If engine is not "reportlab".
ImportError	If reportlab is not installed (pip install phonometry[report]).

impact_improvement

impact_improvement(
    bare: float | Sequence[float] | np.ndarray,
    with_covering: float | Sequence[float] | np.ndarray,
    frequencies: float | Sequence[float] | np.ndarray,
    *,
    background: float | Sequence[float] | np.ndarray | None = None,
) -> FloorCoveringImprovementResult

Improvement of impact sound insulation ΔL of a floor covering (ISO 16251-1).

The acceleration levels without (L0) and with (L1) the specimen may be given either as one value per band (already averaged over the tapping-machine and accelerometer positions) or, for the raw measurement, as a (positions, bands) array. The standard’s order of operations is followed: the background correction (Formula (2)) is applied per position, then the level difference ΔLt,a = L0 − L1 (Formula (3)), then the arithmetic mean over positions ΔL = mean(ΔLt,a) (Formula (4)), necessary because Formula (2) is non-linear, so correcting must precede averaging.

Parameters

Name	Description
bare	Bare-plate acceleration level L0, in dB; (bands,) or (positions, bands).
with_covering	Level with the specimen L1, in dB; same shape as bare.
frequencies	One-third-octave band centre frequencies, in Hz ((bands,)).
background	Optional background-noise level Lb, in dB; (bands,) (applied to every position) or (positions, bands). When given, L0 and L1 are background-corrected (Formula (2)) per position before the difference, and bands where any position hits the 1,3 dB limit are flagged.

Returns: FloorCoveringImprovementResult (ΔL per band).

Raises

Exception	When
ValueError	Mismatched shapes or non-finite values.

improvement_octave_bands

improvement_octave_bands(
    improvement: Sequence[float] | np.ndarray,
    frequencies: Sequence[float] | np.ndarray,
) -> tuple[np.ndarray, np.ndarray]

Convert a one-third-octave improvement spectrum to octaves (Formula (5)).

ΔLoct = −10 lg[(1/3) Σ_{n=1..3} 10^(−ΔL_n/10)] dB over the three thirds of each octave.

Parameters

Name	Description
improvement	Improvement ΔL per one-third-octave band, in dB.
frequencies	The matching one-third-octave centre frequencies, in Hz; must contain whole octave triplets (centre / centre·2^(±1/3)).

Returns: (octave_freqs, ΔLoct).

Raises

Exception	When
ValueError	The thirds do not group into complete octave triplets.