Page 60 - January 2009

The Business of Acoustics
Dick Stern
Applied Research Laboratory, The Pennsylvania State University PO Box 30, State College, Pennsylvania 16804
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ETS-Lindgren announced the opening of its new Acoustic Research Laboratory featuring state-of-the-art chambers for acoustic test services. With its hemi-anechoic chamber, two reverberation chambers, imped- ance tubes and supporting acoustic test equipment and soft- ware, the laboratory now offers product noise emission testing and structural/architectural acoustic testing. Acoustic field testing services are also available upon request. The laboratory is ISO 17025 accredited under the US Department of Commerce NIST National Voluntary Laboratory Accreditation Program (NVLAP).
Product noise emission
testing is commonly performed
in the double-walled hemi-ane-
choic chamber that is designed
to measure very low noise
emissions from products and devices at 80 Hz and above. Outside chamber dimensions are 8.5 m long x 8.5 m wide x 7 m high. This chamber is ideal for testing sound power and pressure levels as well as small fan noise. Products tested include Information Technology Equipment (ITE) such as laptop computers and associated printers, home appliances, garden equipment - essentially any noise emitting device may be tested in this chamber. Commonly referenced standards for testing in this chamber include ISO 3744, ISO 3745, ISO 7779, ISO 11201, and ECMA 74.
Structural/architectural acoustic testing is performed in the reverberation chambers. With transmission loss testing of wall samples, windows, doors, automobile panels and the
like, customers can determine how much sound energy is transmitted through a product sample at specific frequencies. Sound absorption testing may also be performed in these chambers to determine how much sound energy is absorbed by products. Sound insulation products, fabrics, and wall absorbers for theaters are a few such products tested. The source chamber measures 7.4 m long x 5.9 m wide x 4.8 m high; the receive chamber measures 7.4 m long x 9.2 m wide x 6 m high. ASTM E90, ASTM C423, ASTM E596, and ISO 3741 are the most commonly referenced standards for testing in these chambers.
“We’re very excited about the acoustic testing services we can now offer our customers,” said Douglas Winker, Ph.D., Acoustic Engineer for ETS-
Lindgren. “We designed these chambers for the best per- formance possible and worked closely with our facility per- sonnel to ensure the parent building that houses these chambers enhances their performance. For example, the hemi-anechoic inner chamber sits on a 50 ton isolated con- crete slab. The reverberation chambers sit on individual floating concrete slabs.” Dr. Winker added, “With our NVLAP accreditation, customers can be confident that we have a total quality system in place with instrumentation traceable to NIST and experienced technicians who pro- duce accurate measurement data.” For more information on acoustic testing services, visit www.ets-lind- gren.com/labservices.
Editor’s Note—The items printed in “The Business of Acoustics” are reported for informational purposes only and are not necessarily endorsements by the Editor, Acoustics Today, or the Acoustical Society of America.
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