ASTM C423 — Sound absorption and sound absorption coefficients by the reverberation room method
The North American equivalent of ISO 354, reporting NRC and SAA. Choose this when your buyer specifies ASTM.
At a glance
- Standard
- ASTM C423
- Published by
- ASTM International
- Title
- Sound absorption and sound absorption coefficients by the reverberation room method
- Status at ALT
- Traceable — outside the accredited scope
Accreditation status
This standard sits outside ALT’s accredited scope. The measurement is made to the method with traceable reference equipment, and the report says so plainly — it does not carry the accreditation mark. If your specification, regulator or customer requires an accredited result, tell us before you book and we will say whether we can meet it.
Before you commit to this standard
Two things decide whether a result to this standard will be accepted: whether the measurement was made by a laboratory whose scope covers it, and whether the specimen and conditions matched what the standard actually requires. A number produced outside either of those is not wrong, but it is not evidence either.
If you are not certain which standard your specification calls for — and specifications frequently name a superseded edition, or name an ISO standard where the ASTM equivalent is what the market expects — send us the clause and we will tell you what it means in practice before you spend anything.
Standards usually specified alongside it
| Standard | What ALT does with it | Status |
|---|---|---|
| ISO 354 Acoustics — Measurement of sound absorption in a reverberation room | Sound absorption coefficient of building and acoustic products on a 10–12 m² specimen. Reported per one-third-octave band with αw to ISO 11654. | Traceable — not in accredited scope |
| ISO 11654 Sound absorbers for use in buildings — Rating of sound absorption | Converts the measured absorption curve into the single-number rating αw and absorption class A–E. | Traceable — not in accredited scope |