Quality testing of acoustical panels is critical. As an architect or builder, knowing and trusting specifications of wood fiber panels used in a design means reliable and predictable results.
In a previous post, we introduced Riverbank Acoustical Laboratories (RAL), our partner in product testing, and provided some background about the company. Below, we highlight their methodology and the procedures that establish them as a top acoustical-testing laboratory.
Using the ASTM C423 (NRC) method is one way RAL ensures quality testing. ASTM C423 defines NRC as a specific rating; this method measures the reverberation time of the empty chamber and the reverberation of the chamber with the applied test material. The Wallace-Sabine equation calculates the absorption ability of the test material.
For example, a ceiling tile with an NRC rating of .65 means that tile has roughly a sixty-five-percent sound-absorption rate. This method can apply to a wide variety of material (from wood fiber to fiberglass) and returns a high degree of success. RAL can determine the sound-absorption performance of many architectural surfaces or finishes.
RAL has one of the world’s top testing chamber. Their large-diffuse-field reverberation chamber (known as Room 0) was designed by Wallace Sabine, the original RAL stakeholder. Since 1918, this chamber remains the gold standard of its type because of its incredibly thick concrete walls and precise geometric proportions that produce an even, diffused reverberation.
RAL utilizes a Bruel & Kjaer LAN-XI hardware interface analyzer, coupled with Pulse Labshop software and a custom programmed software interface. RAL also uses Bruel & Kjaer microphones, a Bruel & Kjaer microphone rotator, and a custom JBL sound-source. The lab continuously improves their methods for higher levels of accuracy. Some RAL engineers serve on the ASTM E33 committee that develops the ASTM Building Acoustics standards.
Some of the strictest organizations have accredited RAL as an ISO 17025 Laboratory Quality system: National Voluntary Laboratory Accreditation Program (administered by the National Institute of Standards and Technology), Underwriter’s Laboratories (an independent certification body), and the city of Los Angeles. A lab is legitimate when it meets these standards. These organizations have also accredited RAL to their ASTM and ISO testing procedures.
How do you ensure that the acoustical panels you choose meet standards? You must consider the testing lengths a company goes to for their product. When a company is backed by a world-renown acoustical-testing laboratory that uses most-recent technology, architects and builders can feel comfortable using their products. For more information on how quality acoustical panels control noise and enhance surroundings, reach out to our Cardinal Acoustics experts. We’re here to help.