GypsumBroadband absorber
Data source
PTB reference data
Physikalisch-Technische Bundesanstalt
Source: H. Lenz, Marktübersicht schallabsorbierende Anordnungen, Ruhr Universität Bochum, 1981, Seite 195
Value from the PTB table, not verified
Knauf Perllit acoustic tile No. 74
Perllit acoustic tile – No. 74
PTB reference data
Original description
Knauf Perllit acoustic tile No. 74
Material properties
Manufacturer: Knauf Hauptverwaltung Iphofen
Wall distance: 2 in, 20 in
Perforation: 5.8 %
Up to fire class: at least fire-retardant
Mounting: seamless installation
Measurement data
Sound absorption
Reverberation chamber (ASTM C423 / ISO 354)· 2 variants
NRC
0.45
Frequency values
αp per octave band
| f (Hz) | 125 | 250 | 500 | 1k | 2k | 4k |
|---|---|---|---|---|---|---|
| αp | 0.80 | 0.55 | 0.50 | 0.45 | 0.35 | 0.20 |
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| Compare | Value | |
|---|---|---|
| 20 in | NRC0.45 | |
| 2 in | NRC0.55 |
NRC: 0.45 (derived from ISO 354 lab data)
Weight / density: ca. 16 kg / m²
Dimensions: 625 x 25 in
Measured values as a table (2 measurements)
| Build-up | NRC | 100 Hz | 125 Hz | 160 Hz | 200 Hz | 250 Hz | 315 Hz | 400 Hz | 500 Hz | 630 Hz | 800 Hz | 1000 Hz | 1250 Hz | 1600 Hz | 2000 Hz | 2500 Hz | 3150 Hz | 4000 Hz | 5000 Hz |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ca. 16 kg / m² · 50 mm | 0.55 | 0.14 | 0.16 | 0.21 | 0.39 | 0.55 | 0.78 | 0.85 | 0.83 | 0.66 | 0.56 | 0.42 | 0.34 | 0.32 | 0.32 | 0.25 | 0.20 | 0.15 | 0.12 |
| ca. 16 kg / m² · 500 mm | 0.45 | 0.83 | 0.79 | 0.73 | 0.66 | 0.50 | 0.49 | 0.48 | 0.52 | 0.53 | 0.45 | 0.45 | 0.40 | 0.38 | 0.34 | 0.28 | 0.25 | 0.16 | 0.15 |
Measured values as a table (2 measurements)
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