Brüel & Kjær

Brüel & Kjær (Sound and Vibration Measurement A/S)

Type	(Private company)
Industry	Engineering Sound & Vibration
Founded	28th of November, 1942
Headquarters	Nærum, Denmark
Area served	Worldwide
Key people	Lars Rønn (Managing Director)
Products	Sound Measurement, Vibration Systems
Revenue	DKK991 million (2011)[1]
Profit	DKK186 million (2011)[2]
Employees	1,150 (2013)
Parent	Spectris
Website	www.bksv.com

Brüel & Kjær (Sound and Vibration Measurement A/S) is a Danish multinational engineering and electronics company headquartered in Nærum, near Copenhagen. It is the world's largest manufacturer and supplier of sound and vibration measurement equipment, systems and solutions,^[3][4] Brüel & Kjær is a subsidiary of UK-based Spectris plc which has annual sales of £1.1bn and employs around 7,500 people worldwide across its four business segments

Founders

Brüel & Kjær was founded by Per Vilhelm Brüel (b. March 15, 1915) and Viggo Kjær (b. June 5, 1914 - d. 25th July 2013) on November 28, 1942. The two men met while studying at the The Polytechnic School in Copenhagen (now the Technical University of Denmark). After receiving their M.S. degrees in 1939 they decided to start a company developing instruments for acoustic measurements. Holger Nielsen joined the company as third partner in 1945, and was with the company until his death in 1978.

Operations

Brüel & Kjær's global offices:

• Brüel & Kjær Sound & Vibration A/S Headquarters - Nærum, Denmark.

• Brüel & Kjær Inc. North America - Atlanta, Georgia.

• Brüel & Kjær Canada - Pointe-Claire, Canada.

• Brüel & Kjær UK Ltd.- Hertfordshire, United Kingdom.

• Brüel & Kjær GmbH - Local offices in Bremen and Ismaning, Germany.

• Brüel & Kjaer - Mennecy, France.

• Bruel & Kjaer Italia Srl - Milan, Italy.

• Brüel & Kjær Australia - Local offices in Melbourne and Sydney, Australia.

• Brüel & Kjær Japan - Local offices in Tokyo, Osaka, and Nagoya, Japan.

• Brüel & Kjær GmbH Zweigniederlassung Österreich - Vienna, Austria.

• Brüel & Kjær SVM A/S - Moscow, Russia.

• Brüel & Kjaer Ibérica S.A - Local offices in Madrid and Barcelona, Spain.

• Brüel & Kjær S&V Measurement A/S - Local offices in Borås, Huddinge, and Örebro, Sweden.

• Brüel & Kjær Division of Spectris Korea Ltd. - Sungnam-Si, South Korea.

Brüel & Kjær Corporate Management Team

The corporate management team consists of:^[5]

• Lars Rønn – Managing Director since 2008. Previously, Lars Rønn was President of the Hearing Instruments Division of Sonion A/S, and before this he was Managing Director in NKT Integration A/S. Further, Lars has worked in various management positions at Hitachi Europe Ltd.

• Arne Rasmussen – Vice President Finance & Administration. Arne Rasmussen joined Brüel & Kjær as VP of F&A in 2006. Before joining Brüel & Kjær, Arne was Financial Director at JAI A/S and Financial Manager at Ambu A/S.

• Martin Adams – Vice President Brüel & Kjær Environment Management Solutions, Martin Adams joined the Brüel & Kjær management team in 2009 following the acquisition of Lochard Ltd. Martin was co-founder and CEO of Lochard in 1990 and prior to this worked for Schlumberger and Honeywell Information Systems.

• Alan Humphrey – Vice President of Global Sales, Alan Humphrey joined the management team in 2008. He has worked for Brüel & Kjær as President of Bruel & Kjaer North America Inc. since February 2003. Prior to joining Brüel & Kjær, Alan worked for 15 years at MTS Systems in various management roles.

• Torben Bjørn – Vice President of Operations, Torben Bjørn joined the management team in 1997. Torben has a background of over 30 years in various project and managerial roles in Brüel & Kjær.

• Lars Agerlin – Vice President of Research & Development, Lars Agerlin joined Brüel & Kjær as VP of R&D in 2008. He came from a position as Senior Vice President at SimCorp. Prior to joining SimCorp, Lars worked for 11 years at Nokia in various management roles.

• Alun Crewe – Vice President of Strategic Marketing, Alun Crewe joined the management team in 2008. He has worked for Brüel & Kjær since 2003 as Product Marketing Manager. Prior to joining Brüel & Kjær, Alun worked in various positions for MTS Systems and SDRC in the US and UK.

Products

Some of the products developed over 70 years include:

• 1940s – Precision measurement instruments including radio frequency analysers and Geiger counters.The first Brüel & Kjær instrument produced was Type 2401, a vacuum tube voltmeter. The success of the company started with Type 2301 in 1949. Since then it has been updated a number of times. The latest version, Type 2307, was introduced in 1972. In 1943 Brüel & Kjær launched Type 4301 - the world's first Charge Accelerometer, thus entering the field of vibration measurement.

• 1950s – Sound and vibration measurements, including development of logarithmic level recorders, signal generators and frequency analyzers.

• 1960s – Measurement microphones, preamplifiers and calibrators, along with IEC standardised precision sound level meters.

• 1970s – Parallel analyzers, including the world’s first analyzer to use digital filters.

• 1980s – The first commercially available instrument for sound intensity measurement, and expansions of the range of instruments; for example, dual channel FFT analyzers.

• 1990s – Multichannel and multi-analysis systems, including acoustical holography array systems.

• 2000s – Surface microphones and LAN-XI modular data acquisition hardware. New technologies such as TEDS, Dyn-X, REq-X.

Markets

Aerospace

Airframes

Analysing and helping with the design of airframe structures, Brüel & Kjær's structural dynamics testing encompass modal analysis and virtual model validation and updating for finite element analysis. Operational testing such as vibration troubleshooting and ground vibration tests are covered by a range of scalable systems.^[6]

Aero engines

Brüel & Kjær provides tools to overcome noise and vibration challenges. These ensure the quality of new lighter material applications by modal testing and improving the quality and test efficiency in aero engines. Systems include those for development and measurement of new noise-optimised engine/ acoustic lining designs and propagation code validation (engine duct modal analysis, far-field noise measurement, and acoustic panel in-situ impedance measurement) Brüel & Kjær also supplies in-flight engine monitoring with flight-certified, high-temperature accelerometers.^[7]

Noise is a pressing issue at airports, so any significant development at an airport needs to consider the corresponding change in noise impact. Most airports have noise abatement policies that restrict operations in order to limit the noise impact. Brüel & Kjær provides solutions that link positional data from radars to information about each aircraft operation to actual noise levels measured on the ground. The system knows where aircraft are, what they are, who is operating them and how much noise they make every time they arrive and depart the airfield. This data is processed to help the airport police its noise abatement policies ranging from departure track keeping, monitoring noise limits and levying fines for noisy aircraft, enforcing night curfews and ensuring environmentally efficient procedures are used such as Continuous Descent on Approach. Data is also aggregated to provide management information illustrating trends and reporting activity to stakeholders. A third arm enables the airport to manage, investigate and respond to noise complaints, increasing understanding of the airport and providing important data to track changes in the perception of the environmental impact of the airport.^[8]

Aerospace

Brüel & Kjær supplies products like data acquisition systems and vibration test systems (LDS) to many customers in the aerospace industry such as its LDS V994 shaker, which was used to test NASA's Mars Curiosity rover.^[9] Other systems have tested Astrium's satellite prior to launch,^[10] and performed qualification and acceptance testing, such as the integrated LAN-XI data acquisition systems used by the National Institute for Space Research in Brazil INPE.^[11]

Brüel & Kjær's main customers in this market include

Airbus, Aircraft Strength Research Institute, Boeing, EADS, Eurocopter, Rolls Royce, and Sukhoi.

Some of Brüel & Kjær's space customers are shown on Brüel & Kjær's website here

Defence

Acoustic stealth discretion

Acoustic stealth and discretion play a vital role in ship and submarine operations. Brüel & Kjær supplies systems for noise signature management: acoustic ranging of submarines and surface ships; noise source investigation during design and build; and for acoustic trials and self-noise monitoring during operations. Brüel & Kjær also supplies systems for underwater acoustics, shock testing, noise and vibration testing and structural dynamics testing.^[12]

Identifying noise sources

Brüel & Kjær offers products that cover a wide range of acoustic customer-oriented solutions, ranging from simple sound level measurements to the most sophisticated microphone array systems using advanced algorithms and hardware. These solutions are provided for air-vehicle noise certification, exterior noise analysis such as fly-over testing using acoustic holography, beamforming, SONAH and high-temperature sensors, noise source identification to examine e.g., ramp noise or sonic booms, microphone calibration systems and more.^[13]

Maintaining operational integrity

The company offers products like high-temperature accelerometers that can monitor the health of operational machinery

The company provides products that aid preventative maintenance and manufacturer-specified checks to prolong the health of engines. These products take the form of real-time multi-analysis capabilities that reduce the number of run‑ups/‑downs and gather more data faster for analyses ranging from simple pass-fail overall measurements to in-depth advanced analysis in order to maximize the up-time of aircraft. Brüel & Kjær offers products like high-temperature accelerometers that can monitor the health of operational machinery. The company provides solutions for maintenance, repair and overhaul tasks such as balancing, trim balancing, on-ground engine vibration checks, vibration diagnostics and re-run production tests using real-time analysis. In addition, systems are available for monitoring equipment, engines and gearboxes with permanently placed HUMS sensors and signal conditioners for extreme environments.^[14]

Environmental noise impact testing and monitoring

Brüel & Kjær supplies systems for occupational health, helmet/cabin/cockpit noise assessment, acoustic and human vibration monitoring, urban noise monitoring and noise-mapping of vehicles in order to test and monitor the environmental noise impact, and to look for ways of reducing environmental noise impact on armed forces personnel and local communities. These activities include: Helmet/cabin/cockpit noise assessment, human acoustic and vibration monitoring, urban, airport, industrial and construction noise monitoring, and vehicle noise mapping.^[15]

Brüel & Kjær's main customers in this market

BAE Systems, United States Department of Defense, EADS Military Spain, General Dynamics, Howaldtswerke-Deutsche Werft, Kongsberg Defence, Lockheed Martin, Naval Surface Warfare Center, and Royal Norwegian Navy.

Automotive

Cabin noise

Brüel & Kjær’s innovations within Noise Source Identification (NSI) and acoustical mapping, have led to the Spherical Beamforming system, which quickly creates a 360-degree sound field map overlaid on a picture of the vehicle interior without making any assumptions about the sound field. Noise sources are mapped by differentiating sound levels based upon the direction from which they originate. The method is very quick, allowing a full map to be calculated from a single-shot measurement. As the Spherical Beamformer is just one tool within Brüel & Kjær’s array acoustics suite, the data collected during testing can be stored and easily compared with data acquired using other NSI techniques. This integration allows the engineers to identify important sub-sources on an object in terms of position, frequency content and sound power. Ranking of sub-sources may be used to identify where design changes will most effectively improve the overall noise radiation.^[16]

Wind tunnel testing

Since wind tunnel and test track measurements are often the only way to recreate real-world conditions for model and mule car testing, and are also a good method of validating simulated model data, Brüel & Kjær tries to provide measurement devices that focus on these types of tests, providing specialised solutions for specific needs so that they can perform vehicle pass-by noise contribution studies for cars, trucks and trains, location of high-frequency engine noise sources, and wind-tunnel measurements. Surface microphones mounted on the exterior of a vehicle measure the pressure fluctuations at different positions of the vehicle without drilling holes. Beamforming can be used for noise mapping at a distance from large objects. The data for all points is acquired in a single measurement, saving time and effort.^[17]

Setting targets

Brüel & Kjær’s sound quality solutions provide the tools for recording, analysing, auditioning, dissecting, and synthesising sounds. The range enables the use of simulation models and test data to develop modifications to improve the sound quality and to achieve the ultimate objective of designing the desired sound characteristics into the product.^[18]

Benchmarking

Brüel & Kjær has developed an NVH tool for surreptitious recording and analysis called SoNoScout. It can be carried in the tester’s pocket on a train or bus without distracting the passengers or in a competitor’s vehicle where it can be combined with a GPS unit to generate a map of the test route, measure speed and even generate an RPM profile. The software runs on a PDA with microphones binaurally mounted on a headset for quick recording.^[19]

Material testing

Brüel & Kjær’s PULSE Acoustic Material Testing solution gives manufacturers and sub-suppliers the tools to measure all materials for sound and vibration reduction against design specifications and validate their acoustic properties. The integrated solution includes a selection of tube kits and software that determines the acoustical properties - whether the materials are used to absorb airborne sound or to reduce airborne sound transmission.^[20]

Brüel & Kjær's main customers in this market

Robert Bosch GmbH, Caterpillar Inc., Continental AG, Daimler AG, Ferrari, Ford, Goodyear Tire and Rubber Company, Harley Davidson, Isuzu, Michelin, Nissan, Toyota, and Volvo.

Telecom and audio

Brüel & Kjær provides products to telecom and audio customers – from transducers to measurement, analysis and reporting for evaluation of electroacoustic devices:^[21]

• A dedicated platform that includes couplers, microphones, amplifiers, analyzers, calibrators, sound sources, and measurement and analysis software.
• Specialised standards-based telephone test systems for all communication technologies, including GSM, UMTS, AMPS, CDMA, W-CDMA, Bluetooth and VoIP.
• Exceptional ear and mouth simulators.
• Advanced material testing, modal analysis, sound quality and environmental solutions for development, benchmarking, production and quality assurance testing.

Entertainment systems

Brüel & Kjær products test and calibrate loudspeakers and entertainment systems.

In addition to sound level meters, measurement microphones, filters and various types of audio analyzers B&K had a line of phonograph records. This line included the following titles:

Bruel&Kjaer QR2007 Monophonic Gliding Frequency Record – 20-20000 c/s 45 rpm

Frequency Sweeps: logarithmic 20 c/s to 20 kc/s in 15 seconds

Recording Characteristic: IEC Standard no 3 without treble emphasis (constant velocity above 1 kc/s)

Recorded Velocity at 1 kc/s: 3.16 cm/s rms

Bands 1-10: lateral cut

Bruel&Kjaer QR2008 Pick-up Test Record: spot frequencies, reference tones, lateral and vertical tracking, log sweep

Section 1: spot frequencies 20-16-12.5-10kc/s,0.6cm/s rms at 45deg

Band 1: 45 deg left modulation (A)

Band 2: 45 deg right modulation (B)

Section 2: reference tones 1kc/s, 4x60 sec, 2.24 cm/s rms at 45deg (3.16 cm/s lateral or vertical)

Band 1: 45 deg left (A)

Band 2: 45 deg right (B)

Band 3: lateral (A+B)

Band 4: vertical (A-B)

Section 3: lateral tracking test, 100 c/s (A+B), 6x15 sec

Band 1: 0.001 cm/s peak amplitude

Band 2: 0.002 cm/s peak amplitude

Band 3: 0.003 cm/s peak amplitude

Band 4: 0.004 cm/s peak amplitude

Band 5: 0.005 cm/s peak amplitude

Section 4: vertical tracking test, same as section 3, vertical (A-B) modulation

Section 5: log frequency sweeps, 10 c/s – 100 c/s, 16.6 sec, 0.00113 cm/s peak constant amplitude

Band 1: 45 deg left (A)

Band 2: 45 deg right (B)

Band 3: lateral (A+B)

Band 4: vertical (A-B)

Section 6: same as section 1 but with small groove speed

Bruel&Kjaer QR2009 Stereophonic Gliding Frequency Record, 20 - 20000 c/s, 45rpm

Frequency Sweeps: logarithmic 20 c/s to 20 kc/s in 50 seconds

Recording Characteristic: IEC Standard no 3 without treble emphasis (constant velocity above 1 kc/s)

Recorded Velocity at 1 kc/s: 2.24 cm/s rms in 45 deg modulation, (3.16 cm/s rms in lateral and vertical modulations)

Bands 1 and 5: 45 deg left modulation (A)

Bands 2 and 6: 45 deg right modulation (B)

Bands 3 and 7: lateral modulation (A+B)

Bands 4 and 8: vertical modulation (A-B)

Bruel&Kjaer QR2010 Gliding Frequency Record – 5 Hz – 45 kHz

Bruel&Kjaer QR2011 Pink Noise Test Record

Side One:

Band 1: left calibration, 1 kHz 1/3 octave pink noise, 60 sec

Band 2: left measuring signals, 20 Hz to 20 kHz 1/3 octave pink noise, 500 sec

Band 3: right calibration, 1 kHz 1/3 octave pink noise, 60 sec

Band 4: right measuring signals, 20 Hz to 20 kHz 1/3 octave pink noise, 500 sec

Side Two:

Band 1: left+right calibration, 1 kHz 1/3 octave pink noise, 60 sec

Band 2: left+right measuring signals, 20 Hz to 20 kHz 1/3 octave pink noise, 500 sec, with vocal frequency call out

Band 3: left+right measuring signals, 20 Hz to 20 kHz 1/3 octave pink noise, 150 sec, no comments

Band 4: left+right phase check, 20 Hz to 20 kHz wide range pink noise

Band 4: left-right phase check, 20 Hz to 20 kHz wide range pink noise

Band 5: left+right phase check, 20 Hz to 1 kHz wide range pink noise

Band 5: left+right phase check, 1 kHz to 4 kHz wide range pink noise

Band 5: left+right phase check, 4 kHz to 20 kHz wide range pink noise

Band 6: left+right resonance check, 20 Hz to 1 kHz sine sweep, 85 sec

Band 7: left+right, 20 Hz to 20 kHz wide range pink noise, 240 sec

Hearing aids and telephones

Brüel & Kjær supplies the telecom industry with a production line testing solution to test the audio quality of mobile and stationary telephones, headsets, and sub-components:

• Simple pass/fail systems
• Test system enhancements like microphones, head, ear or mouth simulators, laser vibrometers, couplers, turntables, anechoic box or specialized software, can be added individually or together to an already existing production test system.
• Dual-purpose hardware like multi-channel analyzers, calibrators, amplifiers, data management software, etc., that can be used both on the production line and in R&D.
• Customised manual, half- or fully automated test configurations that meet specialised needs for precision and repeatability now and in the future.

Organisational developments

In 1992 Brüel & Kjær was sold to AGIV (a German holding company), and split into a number of separate companies:

• Brüel & Kjær Sound and Vibration Measurement A/S (the core sound and vibration market)
• Brüel & Kjær Vibro (machinery condition monitoring)
• B-K Medical (ultrasonic medical diagnostic instruments)
• Innova Air Tech Instruments A/S (gas analysis instrumentation)
• Danish Pro Audio (studio microphones)

After the division of the company, a number of former employees left to form G.R.A.S. Sound and Vibration. AGIV included the Brüel & Kjær split companies within its Spectris Division, which comprised Brüel & Kjær, Hottinger Baldwin Messtechnik GmbH (HBM), and BTG Instruments GmbH. In July 2000, the Spectris Division was sold to Fairey Group Ltd. (a British Company), and in May 2001, Fairey Group changed its name to Spectris Plc.

Brüel & Kjær acquired LDS Test & Measurement in January 2009,^[22] and, in February 2009, acquired Lochard Ltd.^[23]

See also

• Acoustical measurements and instrumentation

References

Similar Companies / Competitors

• Sensidyne Sound & Vibration Instruments

External links

Wikimedia Commons has media related to Brüel & Kjær.

• Brüel & Kjær (Sound and Vibration Measurement A/S) homepage
• Bruel & Kjaer UK homepage