Source: https://jmrplens.github.io/phonometry/buildings/insulation/insulation-lab/ # Laboratory Insulation Measurement To rate a building element on its own (a wall type, a floating floor, a window) you take it to a qualified laboratory, where suppressed flanking makes the direct transmission the whole story. This page covers the ISO 10140 laboratory chain: the sound reduction index $R$, the normalized impact level $L_\mathrm{n}$, the background-noise correction and the accredited test fiches. Three sibling laboratory methods have guides of their own: the sound-intensity route in [Sound Insulation by Intensity (ISO 15186)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-intensity/), the floor-covering improvement in [Floor-Covering Impact Improvement (ISO 16251-1)](https://jmrplens.github.io/phonometry/buildings/design/impact-improvement/) and the junction measurement in [Laboratory Flanking Transmission (ISO 10848)](https://jmrplens.github.io/phonometry/buildings/insulation/flanking-lab/). Field measurement lives in [Field Insulation Measurement (ISO 16283)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-field/), the single-number ratings in [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/), and the prediction that consumes these laboratory ratings in [Predicting Sound Insulation (EN 12354)](https://jmrplens.github.io/phonometry/buildings/design/insulation-prediction/). ## Laboratory measurement (ISO 10140) An [ISO 16283 field measurement](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-field/) yields the primed quantities ($R'$, $L'_\mathrm{n}$): the number a real building achieves, flanking transmission and all. To rate an element on its own (a wall type, a floating floor, a window), you take it to a qualified **laboratory** (ISO 10140), where suppressed flanking makes the *direct* transmission the whole story. The formulas lose their primes: the **sound reduction index** $R$ (not $R'$) and the **normalized impact level** $L_\mathrm{n}$ (not $L'_\mathrm{n}$), with the receiving room's absorption area $A = 0.16\ V/T$ now a known property of the facility: $$ R = L_1 - L_2 + 10 \log_{10}\frac{S}{A}, \qquad L_\mathrm{n} = L_\mathrm{i} + 10 \log_{10}\frac{A}{A_0}, \quad A_0 = 10\ \text{m}^2. $$ The facility itself is what suppresses the flanking: two structurally decoupled reverberation rooms of at least 50 m³ each, with the element under test mounted in a test opening of about 10 m² between them. | | Field (ISO 16283) | Laboratory (ISO 10140) | | :--- | :--- | :--- | | Airborne element index | $R'$ apparent (with flanking) | $R$ direct (flanking suppressed) | | Airborne room pair | $D_\mathrm{nT}$, $D_\mathrm{n}$ (no prime: room quantities) | — | | Impact | $L'_\mathrm{n}$, $L'_\mathrm{nT}$ apparent | $L_\mathrm{n}$ direct | | Single number | $R'_\mathrm{w}$, $D_\mathrm{nT,w}$, $L'_\mathrm{n,w}$, $L'_\mathrm{nT,w}$ | $R_\mathrm{w}$, $L_\mathrm{n,w}$ | | Absorption area | measured in the room | property of the facility | The apostrophe is the flanking marker of building acoustics, and it travels with the quantity into its single number: $R_\mathrm{w}$ rates a laboratory spectrum, $R'_\mathrm{w}$ a field one. The standardized and normalized level differences $D_\mathrm{nT}$ and $D_\mathrm{n}$ carry no prime because they describe the room pair rather than an element, so there is no flanking-free counterpart to mark. In a well-built construction $R'_\mathrm{w}$ lands a few dB below the laboratory $R_\mathrm{w}$ of the same partition; a much larger gap says flanking dominates, and the [EN 12354 model](https://jmrplens.github.io/phonometry/buildings/design/insulation-prediction/) tells you which path carries it. The single-number ratings reuse the very same ISO 717-1/2 engines (`weighted_rating`, `weighted_impact_rating`): an $R$ spectrum rates to $R_\mathrm{w}$ exactly as an $R'$ spectrum rated to $R'_\mathrm{w}$. Before forming the index the receiving-room levels must be **corrected for background noise** (Clause 4.3): the energy subtraction $10 \log_{10}(10^{L_\mathrm{sb}/10} - 10^{L_\mathrm{b}/10})$ applies for a 6–15 dB signal-to-background margin, a fixed 1.3 dB correction (the *limit of measurement*) at or below 6 dB, and no correction at or above 15 dB. ```python import numpy as np from phonometry import building # Source/receiving levels and receiving-room T over the 16 one-third-octave # bands; S is the free test-opening area, V the receiving-room volume. l1 = np.full(16, 80.0) l2 = np.full(16, 40.0) t2 = np.full(16, 0.5) lab = building.lab_airborne_insulation(l1, l2, t2, area=10.0, volume=50.0) print(round(float(lab.r[0]), 1)) # 38.0 R = L1 - L2 + 10 lg(S/A) print(round(float(lab.absorption[0]), 1)) # 16.0 A = 0.16 V / T (m^2) print(lab.rating.rating, lab.rating.c, lab.rating.ctr) # 38 0 0 -> Rw(C;Ctr) # Impact: the tapping-machine level Li normalized to A0 = 10 m^2 gives Ln li = np.array([62.1, 63.2, 63.5, 66.2, 68.5, 70.0, 71.7, 73.1, 73.8, 73.5, 73.8, 73.3, 73.1, 73.0, 72.4, 71.2]) imp = building.lab_impact_insulation(li, t2, volume=50.0) print(round(float(imp.l_n[0]), 1)) # 64.1 Ln = Li + 10 lg(A/A0) print(imp.rating.rating, imp.rating.ci) # 81 -11 -> Ln,w(CI) # Background correction: margins 6 / 1 / 20 dB -> capped / capped / unchanged corrected = building.background_correction([30.0, 33.0, 50.0], [24.0, 32.0, 30.0]) print(np.round(corrected, 1)) # [28.7 31.7 50.0] (1.3 dB cap twice) lab.rating.plot() # measured R vs shifted ISO 717-1 reference (needs matplotlib) ``` A margin at or below 6 dB emits a `LabInsulationWarning` and flags the band as the limit of measurement; catch it with `warnings.simplefilter("error", LabInsulationWarning)`. The automatic rating is formed only when exactly 16 one-third-octave or 5 octave values are supplied (`rating` is `None` otherwise). *The two laboratory quantities of ISO 10140 with their ISO 717 ratings: the airborne $R$ is rated where the reference sits **above** the measurement, the impact $L_\mathrm{n}$ where the measurement sits **above** the reference (a higher impact level is worse). `lab.plot()` and `imp.plot()` draw either panel on its own.*

Show the code for this figure

```python import matplotlib.pyplot as plt import numpy as np from phonometry import building # The ISO 717-1 Annex C wall in an ISO 10140 suite (S = 10 m2, V = 50 m3, # T = 0.8 s) and the ISO 717-2 Annex C floor under the tapping machine. r = np.array([20.4, 16.3, 17.7, 22.6, 22.4, 22.7, 24.8, 26.6, 28.0, 30.5, 31.8, 32.5, 33.4, 33.0, 31.0, 25.5]) l1 = np.full(16, 90.0) t2 = np.full(16, 0.8) lab = building.lab_airborne_insulation(l1, l1 - r, t2, area=10.0, volume=50.0) li = np.array([62.1, 63.2, 63.5, 66.2, 68.5, 70.0, 71.7, 73.1, 73.8, 73.5, 73.8, 73.3, 73.1, 73.0, 72.4, 71.2]) imp = building.lab_impact_insulation(li, t2, volume=50.0) # One line each — R (or Ln) vs its shifted ISO 717 reference: lab.plot() imp.plot() plt.show() # By hand, both panels from the results' fields: fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(11, 4.5)) ax1.semilogx(lab.rating.band_centers, lab.r, "o-", label="measured R") ax1.semilogx(lab.rating.band_centers, lab.rating.shifted_reference, "s--", label="shifted reference") ax1.set_title(f"Rw = {lab.rating.rating} dB") ax2.semilogx(imp.rating.band_centers, imp.l_n, "o-", label="normalized Ln") ax2.semilogx(imp.rating.band_centers, imp.rating.shifted_reference, "s--", label="shifted reference") ax2.set_title(f"Ln,w = {imp.rating.rating} dB") for ax in (ax1, ax2): ax.set_xlabel("Frequency [Hz]") ax.legend() ax1.set_ylabel("Sound reduction index R [dB]") ax2.set_ylabel("Impact sound pressure level Ln [dB]") plt.show() ```

### `lab_airborne_insulation()` / `lab_impact_insulation()` parameters | Parameter | Type | Units | Range / default | Notes | | :--- | :--- | :--- | :--- | :--- | | `l1` / `l2` | 1D or 2D array | dB | one/band, or `(positions, bands)` | Source / receiving levels (airborne) | | `li` | 1D or 2D array | dB | one/band, or `(positions, bands)` | Impact SPL from the tapping machine (impact) | | `t2` | 1D array | s | > 0, one per band | Receiving-room reverberation time | | `area` | float | m² | > 0 | Free test-opening area $S$ (airborne only) | | `volume` | float | m³ | > 0 | Receiving-room volume $V$ | `lab_airborne_insulation()` returns a `LabAirborneInsulationResult` (`r`, `absorption`, `rating`); `lab_impact_insulation()` a `LabImpactInsulationResult` (`l_n`, `absorption`, `rating`); `background_correction(signal_and_background, background)` returns the corrected levels directly. ### ISO 10140 laboratory test report (`.report()`) Both laboratory results write the one-page ISO 10140 test report directly, laid out like the accredited laboratory reports rated per ISO 717. `LabAirborneInsulationResult.report()` renders the sound reduction index $R$ fiche (ISO 10140-2:2010) and `LabImpactInsulationResult.report()` the normalized impact sound pressure level $L_\mathrm{n}$ fiche (ISO 10140-3:2010). Each fiche names the laboratory standard in its basis line, evaluates the ISO 717-1 / ISO 717-2 single-number rating (16 one-third-octave bands from 100 Hz to 3150 Hz, or the 5 octave bands), states the quantity to one decimal place both in tabular form and as a curve against the shifted reference curve, boxes the laboratory rating (`Rw (C; Ctr)` or `Ln,w (CI)`) and prints the statement that the evaluation is based on laboratory measurement results obtained by a precision method. Because a qualified suite suppresses flanking transmission, the reported quantity is the *direct* $R$ / $L_\mathrm{n}$, not the field $R'$ / $L'_\mathrm{n}$. `verbose=True` annexes the per-band equivalent sound absorption area $A = 0.16\,V/T$ (ISO 10140-4:2010) beside the reported quantity, the normalization datum the laboratory report carries. Metadata (client, specimen, mounting, room volumes, climatic conditions), the requirement verdict (airborne passes at or above it, impact at or below it), `language="es"` and the `phonometry[report]` extra behave exactly as in the ISO 717 and ISO 16283 fiches. ```python import numpy as np from phonometry import building, ReportMetadata # Laboratory airborne: source/receiving levels and T per one-third-octave band l1 = np.full(16, 90.0) r = np.array([20.4, 16.3, 17.7, 22.6, 22.4, 22.7, 24.8, 26.6, 28.0, 30.5, 31.8, 32.5, 33.4, 33.0, 31.0, 25.5]) lab = building.lab_airborne_insulation( l1, l1 - r, np.full(16, 0.8), area=10.0, volume=50.0 ) lab.plot() # measured R vs shifted ISO 717-1 reference (needs matplotlib) metadata = ReportMetadata( specimen="100 mm autoclaved aerated concrete block wall", client="Example client", area=10.0, mass_per_area=75.0, source_volume=53.0, receiving_volume=50.0, test_room="Transmission suite (example)", mounting="Type A mounting, mortar-bedded perimeter (ISO 10140-1)", measurement_standard="ISO 10140-2", laboratory="Phonometry Reference Laboratory", report_id="PHN-2026-0143", requirement=30.0, # Rw >= 30 dB -> PASS/FAIL row ) lab.report("Rw_lab.pdf", metadata=metadata) # Rw (C; Ctr) lab.report("Rw_lab_chain.pdf", metadata=metadata, verbose=True) # f | A | R # Laboratory impact: tapping-machine levels in the receiving room li = np.array([62.1, 63.2, 63.5, 66.2, 68.5, 70.0, 71.7, 73.1, 73.8, 73.5, 73.8, 73.3, 73.1, 73.0, 72.4, 71.2]) imp = building.lab_impact_insulation(li, np.full(16, 0.8), volume=50.0) imp.report("Lnw_lab.pdf", metadata=ReportMetadata(requirement=80.0)) # Ln,w (CI) ``` Rendered examples of both laboratory fiches, regenerated with `make reports`, are kept in the repository. Click either preview to open the PDF: [](https://raw.githubusercontent.com/jmrplens/phonometry/main/.github/reports/iso10140_airborne_example.pdf) *Laboratory airborne fiche (`LabAirborneInsulationResult.report`), Rw (C; Ctr).* [](https://raw.githubusercontent.com/jmrplens/phonometry/main/.github/reports/iso10140_impact_example.pdf) *Laboratory impact fiche (`LabImpactInsulationResult.report`), Ln,w (CI).* ## Beyond the pressure method Three sibling laboratory measurements used to share this page and now have guides of their own. When flanking is too high for the pressure method, [Sound Insulation by Intensity (ISO 15186)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-intensity/) reads the transmitted power directly off the radiating face. For a soft floor covering, [Floor-Covering Impact Improvement (ISO 16251-1)](https://jmrplens.github.io/phonometry/buildings/design/impact-improvement/) replaces the two-room suite with a small heavyweight mock-up. And the junction data the EN 12354 prediction consumes is measured per [Laboratory Flanking Transmission (ISO 10848)](https://jmrplens.github.io/phonometry/buildings/insulation/flanking-lab/). ## References - Hopkins, C. (2007). *Sound insulation*. Butterworth-Heinemann. ISBN 978-0-7506-6526-1. [doi:10.4324/9780080550473](https://doi.org/10.4324/9780080550473). The reference monograph for laboratory sound-insulation measurement and the interpretation of the laboratory indices. - Vigran, T. E. (2008). *Building acoustics*. CRC Press. ISBN 978-0-415-42853-8. [doi:10.1201/9781482266016](https://doi.org/10.1201/9781482266016). The transmission theory of single and double constructions that laboratory indices quantify. ## Standards ISO 10140-2:2010, ISO 10140-3:2010 and ISO 10140-4:2010, which provide the laboratory $R$ and $L_\mathrm{n}$ with the background-noise correction and the measurement procedures behind them. **Not covered.** The ISO 10140-4:2010 procedure and the ISO 10140-1:2010 and **ISO 10140-5:2010** facility and mounting requirements are documented above and implemented nowhere: nothing checks the position counts, the separations, the averaging times, the band range, the test-opening geometry or the loss-factor requirement. The mounting condition survives only as free text in the report metadata — which is what ISO 10140-1 asks for, since it requires a mounting to be *described* rather than picked from a list. Nothing estimates the suite's $R'_\text{max}$ either, so a result approaching the facility's ceiling is produced without complaint; that qualification comes from the laboratory's own Annex A tests. The neighbouring laboratory measurements have their own pages: intensity (ISO 15186), the floor-covering improvement (ISO 16251-1) and flanking transmission (ISO 10848). ## See also - [Field Insulation Measurement (ISO 16283)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-field/): the in-building airborne, impact and façade measurements, their single-number ratings and their uncertainty. - [Predicting Sound Insulation (EN 12354)](https://jmrplens.github.io/phonometry/buildings/design/insulation-prediction/): the flanking model that consumes the laboratory $R$, $L_\mathrm{n}$ and $K_{ij}$. - [Sound Insulation by Intensity (ISO 15186)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-intensity/): the direct-power alternative for high-flanking situations. - [Floor-Covering Impact Improvement (ISO 16251-1)](https://jmrplens.github.io/phonometry/buildings/design/impact-improvement/): the small-mock-up $\Delta L$ of soft floor coverings. - [Laboratory Flanking Transmission (ISO 10848)](https://jmrplens.github.io/phonometry/buildings/insulation/flanking-lab/): the measured junction vibration reduction index. - [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/): the reference-curve engine behind $R_\mathrm{w}$ and $L_\mathrm{n,w}$. - [Sound Power](https://jmrplens.github.io/phonometry/devices/emission/sound-power/): the $L_W$ methods that share the absorption-area machinery of the receiving room. - API reference: [`building.measurement.lab_insulation`](https://jmrplens.github.io/phonometry/reference/api/building/lab-insulation/).