Main Menu

See All Acoustic End-of-Line Test Systems See All DAQ and instruments See All Electroacoustics See All Software See All Transducers See All Vibration Testing Equipment See All Academy See All Resource Center See All Applications See All Industries See All Insights See All Services See All Support See All Our Business See All Our History See All Our Sustainability Commitment See All Global Presence

Main Menu

See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors See All Transmission & Gearboxes See All Turbo Charger See All Industrial electronics See All S&V Signal conditioner See All DAQ Systems See All Power Analyser See All S&V Hand-held devices See All High Precision and Calibration Systems See All Test Solutions See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All DAQ Software See All Drivers & API See All Utility See All Vibration Control See All Acoustic See All Current / voltage See All Displacement See All Load Cells See All Pressure See All Strain Gauges See All Vibration See All Torque See All LDS Shaker Systems See All Vibration Controllers See All Power Amplifiers See All Accessories for Vibration Testing Equipment See All Training Courses See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All Our People

Main Menu

See All QuantumX See All LAN-XI See All SomatXR See All MGCplus See All CANHEAD See All Optical Interrogators See All GenHS See All API See All Microphone Cartridges See All Microphone Sets See All Microphone Pre-amplifiers See All Sound Sources See All Acoustic Calibrators See All Special Microphones See All Accessories for acoustic transducers See All Experimental testing See All Transducer Manufacturing (OEM) See All CCLD (IEPE) accelerometers See All Charge Accelerometers See All Rotating See All Non-rotating (calibration) See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Dynamic Weighing See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management

Europe’s Largest Refrigeration And Air Conditioning Laboratory

It covers an astounding 8500 square metres, houses an interdisciplinary team of 40 engineers and technicians, has temperatures ranging from +50°C to –40°C and climate chambers big enough to accommodate a refrigerated trailer – welcome to Europe’s largest independent testing laboratory, the Center of Competence for Refrigeration and Air Conditioning.

Based in the Bavarian town of Olching near Munich and operated by TÜV SÜD Industrie Service GmbH, the premises are also home to an innovative laboratory for a new in-house field of activities – technical acoustics.
“TÜV SÜD’s decision to bring acoustic measurements in-house instead of outsourcing them was prompted by rising demands from customers and increasingly strict test regulations,” explains Andreas Klotz, Head of the Testing Laboratory for Refrigeration and Air Conditioning.

Limiting noise emissions

Ventilation and extraction systems, fans in refrigeration units or vehicles, motors and pumps in machinery or refrigeration systems all produce noise that is perceived as unpleasant. To make sure that any unwanted noise from technical components is below perceptible levels, or to test whether the sounds produced are within the required tolerances, TÜV SÜD has established ideal conditions for such measurements: a 10 × 10 × 7 m semi-anechoic chamber with a volume of around 588 m3. The cavity-walled, room-in-room solution is made of precast concrete parts. The inner cube has a self-contained foundation that is separate from the rest of the building and a 60 cm thick layer of multiple elastomer panels acts as a vibration absorber, resulting in a room with an incredibly low noise level of only 5 dB(A).

“Each customer has different expectations and ideas. For us, as a technical service provider, this means that we need to re-invent ourselves daily,” says Andreas Klotz. “The key to success lies in flexibility and individual customer care.” To ensure this, TÜV SÜD needed a measurement system that was not only suitable for carrying out measurements on recooling systems within the scope of certification, but also met the demands of automotive suppliers for optimizing the sound of closing a glove compartment or for the approval of alarm systems.

Kitting out the lab


Opting for a Brüel & Kjær multi-channel data acquisition and analysis solution, Andreas Klotz explains why: “Brüel & Kjær is the only supplier offering package solutions that include everything from microphones to analyzer software, topped off with first-class support. Other arguments in favour of Brüel & Kjær are the quality of its products and the reputation of its brand. This technology ensures that our customers will obtain reliable and robust measurement results.”
The laboratory is equipped with 16 channels of LAN-XI data acquisition hardware, where the ability of being able to use the modules in a distributed system ensures short and orderly cable runs. The power needed by the modules is supplied by Power over Ethernet (PoE) from a central switch via one network cable. The measuring room and the control station are only connected by a single network cable, a major advantage over other systems that still rely on a traditional rack-mounted system.

TÜV SÜD's technical acoustic experts. From left: Michael Gail, Sebastian Rieger and Thomas Heichele

Full digitization

TÜV SÜD also rigorously oversaw network capability and digitization for all other measured variables recorded directly by the PULSE™ measurement software. The ambient conditions in the measurement room, for example, are read via Ethernet and supplied directly to PULSE via the GADI (Generic Auxiliary Digital Interface) driver. “The requirements related to determining electrical power parameters during acoustic measurements are one of the reasons why TÜV SÜD decided to rely on full digitization and the GADI driver. The electrical power that needs to be measured, for example, extends from the low single-digit range to several kW.

”A standard analogous 0 – 10 V signal does not allow these measurements to be realized with the necessary precision,” explains technical acoustics expert Sebastian Rieger. In this case, TÜV SÜD relies on the high-precision Yokogawa power meters that are likewise actuated via the network and supply measurement data via the GADI driver to PULSE. All relevant measured data that needs to be recorded and the measured acoustic values are, therefore, all captured in one system and stored as one data set in an SQL database.

The road to olching

The acoustics laboratory has already built up a broad client base since it began its operations. Many of the acoustic measurements are performed as services for larger projects in the refrigeration and air conditioning laboratory, particularly within the scope of certification. However, an increasing number of customers in the fields of product and application testing are now also making their way to Olching.

As well as suppliers to the rail and automotive industries, manufacturers of toys, household appliances and garden tools also use the services and the infrastructure available there, which is rounded off by the provision of utilities including freshwater, wastewater and compressed air systems as well as an exhaust gas-extraction system.

Perfect soundscape with sound quality measurement
Perfect soundscape with sound quality measurement