Testing | Checking | Measuring

The acoustic stress test facility at the Fraunhofer Institute for Building Physics IBP is a state-of-the-art testing environment designed to expose technical components to extreme sound pressure levels of up to 160 dB SPL. Typical test objects include sensors and electronics used in aerospace, automotive, and consumer electronics applications. The Maximum Pressure Tests (MPT) are conducted in accordance with AEC-Q103-003 using the High Sound Pressure Source, which generates sound pressure levels exceeding 160 dB at a frequency of 140 Hz.

In the Test Laboratory Emission, environment and hygiene among other things determination of gaseous emissions in test chamber and indoor air, determination of organic emissions from non-metallic automotive components as well as Odor analyses are made.

Our testing facility with solid installation walls can be used to precisely determine the noise generated by plumbing and water installations because a typical residential building is simulated. The testing facility consists of two rooms, one above the other, thus corresponding to a section of a typical residential building with two residential units above one other. Thanks to the way the rooms are arranged – bathroom above bathroom, each with adjoining living room – it is possible to measure the airborne and structure-borne sound generated by installations in one’s own and other people's living areas (requiring noise protection). In conjunction with the attic and basement floors, installations that extend over several floors, such as waste water systems (according to DIN EN 14366-1), drinking water systems or building service equipment, can also be tested.

The building acoustics test laboratory is recognized by the German Institute for Building Technology (DIBt) as an approved Group I testing center authorized to carry out the full range of performance and quality tests according to DIN 4109.

Test Laboratory Hygric properties and inorganic materials

Our test facility for determining the shaft sound level difference of ventilation systems provides a detailed analysis of multi-floor air ducting systems. In accordance with DIN 52210-6:2013, sound transmissions from ventilation ducts, exhaust air systems or individual components such as shaft branches can be measured. The test setup simulates realistic conditions with a variable duct system and separate duct branches for sending and receiving rooms. Strategically placed microphones at important points record the sound levels, delivering precise results to optimize ventilation systems. With a sound level difference of at least 55 dB (Dw), our test facility meets the highest standards for sound insulation analyses.

Testing and determination of the characteristics of chimney systems and their components in regard to thermal, moisture and flow behavior, corrosion resistance, thermal load capacity, gas tightness, construction and function. Determination of parameters relating to energy efficiency, fire resistance and environmental aspects and performance testing of individual and collective heating systems fired by solid and liquid (vaporizing burner) fuels.

Our two acoustic semi-anechoic chambers provide optimal conditions for conducting precise sound measurements. In the first chamber, specially designed for measuring sound power and directional characteristics, you benefit from an environment that is acoustically optimized to simulate the conditions of a free field. The second chamber is also temperature-resistant, making it particularly advantageous when it comes to measuring the noise generated by heat pumps and air-conditioning units. This adaptability makes it possible to test acoustic performance under different climatic conditions, ensuring realistic and practical results.

An environment with room acoustics optimized to reduce reflection is used to simulate the acoustic conditions of a free field above a reflecting plane. Such a room is classified as a semi-anechoic chamber. This environment can be used to perform highly accurate measurements of the radiated sound power from sound sources, as well as their directional characteristics. An acoustic free field is distinguished by the fact that the sound pressure level decreases proportionally with increasing distance from the sound source. This condition is achieved by lining walls and ceilings with special sound-absorbing materials, such as flat absorbers (industry) or wedge absorbers, as in this room. The chamber is about 20 meters long, which allows measurements of sound propagation over obstacles to be performed. Typical tasks include the measurement of sound diffraction or sound shielding via barriers, such as noise barriers, as well as the scattering or absorption of sound by acoustically relevant surfaces.

A few years ago, a test rig was developed at the Fraunhofer Institute for Building Physics IBP in Stuttgart for measuring the dynamic E modulus and loss factor based on ISO 6721-4 (non-resonant method). This method can be used to examine the E modulus and loss factor of foams and soft plastics (such as rubber, silicone, etc.) as a function of frequency.

Sound power is an important parameter for characterizing the noise emissions of machines, devices, and systems, as it quantifies the absolute power of a sound source regardless of its acoustic environment. A common method for determining sound power involves measurements under controlled conditions in the reverberation room, where the sound source operates within a diffuse sound field. The sound power is derived from the sound pressure measurements and corresponds to accuracy class 1. These measurements are carried out in third-octave bands according to DIN EN ISO 3741, covering an extended frequency range from 50 Hz to 10 kHz. Whether ventilation technology, HVAC technology, or other noise sources, the reverberation room facilitates detailed investigations using both direct and comparative methods. Its vibration-damped design and connection to an anechoic chamber provide additional flexibility to simulate a wide range of acoustic scenarios.

Our P3 diagonal test facility enables comprehensive analysis of the longitudinal sound insulation and joint insulation of a wide range of wall systems - from lightweight to solid constructions. Its innovative design, consisting of four adjacent rooms and elastic separating joints, allows for detailed simulation of real-world building and usage scenarios. This test bench meets the requirements of DIN EN ISO 10848-2 and DIN EN ISO 10848-3 standards, ensuring reliable, standard-compliant results. State-of-the-art measurement technology permits precise evaluation of airborne and structure-borne sound transmission in all relevant propagation directions, including direct, longitudinal, and diagonal transmission. These measurement results contribute significantly to optimizing the acoustic performance of your wall systems and meeting market requirements.

In our ceiling testing facility, flat roofs or lightweight ceilings can be installed according to DIN EN ISO 10140 (wooden ceilings). These include flat roofs, industrial roofs, wooden beam ceilings, solid wood ceilings and wood-concrete composite ceilings. The airborne and impact sound insulation of the ceilings, installation noise from bathtubs and shower trays, as well as the reduction of impact sound from screeds, hollow and raised floors, suspended sub-ceilings and much more can be measured effortlessly in the testing facility. The ceilings or roofs are installed on a circumferential bracket. The dimensions of the test object are approx. 4.78 x 3.78 m (L x B).

When raindrops fall on horizontal building elements such as roofs, skylights or window sills, they sometimes generate unwanted noise. This effect can cause noise pollution for building users or neighbors both outside and inside the building. Therefore, our scientists use our rain noise testing facility to measure the sound intensity level Li,A (sound power per 1 m² of roof area) that is generated when reproducible “standard rain” falls on sloping roof surfaces. These measurements are particularly relevant for roof constructions made of materials such as foil cushions, metal or sheet metal, as well as standing seam roofs and profiled roofs (ETFE).

Our suspended ceiling test facility (P5) enables the determination of the longitudinal sound insulation of suspended ceilings in accordance with the standard DIN EN ISO 10848-2:2018. With flexible configuration options, such as a ceiling that is infinitely height-adjustable, we offer optimum adaptation to individual testing requirements - without the need for structural modifications. A highly sound-insulating partition wall between the source and receiving rooms guarantees precise and reproducible measurement results. This technical setup provides ideal conditions for measuring closed suspended ceilings, grid ceilings and systems with integrated ceiling elements.

In our specialized testing facility, we can determine the noise level Lap in accordance with DIN EN ISO 3822. The noise generated by sanitary taps, fittings, valves and other water installation devices is recorded in detail, transmitted via a standardized measuring setup in our measuring lab and then compared with the noise level generated by the installation noise standard (IGN).

At the Fraunhofer IBP screed test stand, the impact sound reduction and airborne sound insulation of ceilings, ceiling coverings, and suspended ceilings, on a solid reference ceiling are examined according to DIN EN ISO 10140. The standardized 140-mm-thick reinforced concrete test ceiling separates two adjacent reverberation rooms, providing optimal conditions for acoustic analyses. Flanking transmission is minimized by additional lining, while the standardized tapping machine and alternative impact sound sources, such as fitness weights or rubber balls, are used for impact noise measurements. The test stand is suitable for floating screeds, cavity floors, raised floors, and various floor coverings. In addition to impact sound measurements, structure-borne sound and modal analyses can also be performed.

In our installation testing facility, the noise from sanitary and water installations can be precisely determined using lightweight dry construction installation walls. The testing facility consists of two rooms, one above the other, which can each be subdivided into a total of four rooms by a (lightweight) installation wall. It thus corresponds to a section of a typical residential building with two residential units above each other with lightweight installation walls. Thanks to the way the rooms are arranged – bathroom above bathroom, each with adjoining living room – it is possible to measure the airborne and structure-borne sound generated by installations in one’s own and other people's living areas (requiring noise protection). In conjunction with the roof and drainage system under the testing facility, installations that extend over several floors, such as waste water systems (according to DIN EN 14366-1), drinking water systems or building service equipment, can also be tested.

At Fraunhofer IBP, sound insulation tests for raised and hollow floors are conducted using various test facilities, including the wall and ceiling test stand, all of which meet the requirements of the DIN EN ISO 10140-5:2021 standard. The flooring system to be examined is installed directly onto the concrete floor of the test stand. A highly sound-insulating partition wall extends from the ceiling to just above the surface of the raised floor between the source and receiving rooms. This partition wall is fitted with mineral wool and a permanently plastic seal to minimize flanking transmission. Measurements are carried out using dodecahedron loudspeakers, standard tapping machines, and rotating microphones. The system’s flexibility allows for the testing of various floor systems, including those with air outlets or floor bulkheads.

In the Fraunhofer IBP reverberation chamber, the sound absorption coefficient of sound absorbers, acoustic panels, noise barriers, and suspended ceilings can be determined. Similarly, the equivalent sound absorption area of items such as mobile partition walls, seatings and other individual objects can be determined. The measurements are carried out according to DIN EN ISO 354 with diffuse sound incidence. Due to its size and construction, the reverberation chamber also offers the possibility to carry out measurements in the low-frequency range. A unique feature of the reverberation chamber is its sliding door, which allows for sound absorption measurements to be carried out under both diffuse sound incidence and free-field conditions. This flexibility makes it possible to simulate a wide range of realistic acoustic scenarios. Additionally, the reverberation chamber is equipped with a vibration-damped structure that minimizes structure-borne sound transmission, ensuring highly accurate measurement results.