DASM – Leading Unit in Vietnam for Sound Absorption Coefficient Testing According to ASTM C423 Standard

DASM is currently evaluated as the number 1 unit in Vietnam for sound absorption coefficient testing according to the international standard ASTM C423 and is the first and only unit in Vietnam with an acoustics laboratory accredited by VILAS in the field of acoustics.

In the field of acoustic science and sound insulation – sound absorption, accurately determining the sound absorption coefficient plays a key role in acoustic design, evaluating material performance, and ensuring technical requirements in construction projects. Among current international standards, ASTM C423 is the most prestigious and widely used standard for measuring sound absorption coefficients in a reverberation room.

DASM Institute – Sound Absorption Coefficient Testing Service in a Reverberation Room According to ISO 354 & ASTM C423

DASM is certified for acoustic testing operations registration

Testing sound absorption performance for Vinh Hung perforated barrier sound-absorbing panels

What is ASTM C423?

ASTM C423 is a standard issued by ASTM International, regulating the method for measuring sound absorption coefficients in a reverberation room. This measurement method allows determining important parameters such as:

• Octave band sound absorption coefficients
• NRC (Noise Reduction Coefficient)
• SAA (Sound Absorption Average)

ASTM standard C423 is commonly used in:

• Acoustic design for theaters, conference rooms, factories
• Inspection and certification of sound-absorbing and sound insulation material performance
• Quality proof documents when participating in construction bidding
• Supporting export procedures for materials requiring sound absorption performance

ASTM C423 standard sound absorption coefficient testing – what conditions are required?

Not every laboratory or unit offering material testing services can conduct sound absorption coefficient testing according to ASTM C423. Because this is an international standard, all factors such as the testing room, measuring equipment, and operators must meet prescribed standards. The regulations include:

• ISO 354 standard reverberation laboratory: A space capable of creating standard reverberation, unaffected by external thermal noise.
• ANSI/IEC standard multi-channel sound measurement equipment: Allows accurate recording of sound data presented fully according to frequency tables.
• Trained and experienced acoustic experts: Operators of equipment and analysts of results must clearly understand the principles and correct interpretation of sound data.
• Internationally accredited testing organization: Only results from ISO/IEC 17025 standard units are internationally recognized.

With such strict requirements, very few units in Vietnam can currently perform material sound absorption coefficient tests according to ASTM C423. And DASM is proud to be one of the few units capable of performing this testing as well as the only unit with an acoustics laboratory meeting VILAS standards.

Procedure for sound absorption coefficient testing according to ASTM C423

1. Preparation of test samples:

• Material samples must reach the specified area (usually a minimum of 6m2)
• Installation according to standard regulations (flat mount or random mount)

2. Initial environmental measurement:

Determine the background reverberation level of the empty room without samples

3. Performing measurement 1 (without samples):

Measure reverberation time in the empty room

4. Performing measurement 2 (with samples):

Measure reverberation time when samples are placed in the room

5. Result analysis:

• Calculate sound absorption coefficients at each frequency band according to standard formulas
• Determine NRC and SAA according to ASTM regulations

Why is DASM the number 1 unit for sound absorption coefficient testing according to ASTM C423?

• VILAS ISO/IEC 17025 standard laboratory

DASM is the only unit in Vietnam accredited with VILAS for acoustic testing

• Modern synchronized equipment

ISO 354 standard reverberation room – international standard measuring equipment

• Experienced acoustic experts

A team of engineers who have performed hundreds of acoustic material tests

• Results are internationally recognized

Data is used for project acceptance, bidding, and export

• Hundreds of typical customers have trusted us: Remak Vietnam, Vinh Hung, a series of sound insulation and sound-absorbing material manufacturing factories in Hanoi and HCMC, contractors, designers, engineers, ....

DASM is always ready to support and advise customers interested in learning about sound coefficient testing services according to ASTM C423; as well as performing standard sound absorption coefficient testing with a strict process, modern equipment, and a team of experienced experts. Contact the DASM Hotline immediately for quick consultation and quotation.