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 Sunday, September 05, 2010
Services
Product development

 

Müller-BBM specializes in design, acquisition, assessment and optimization of sound, vibration and fatigue properties for a vast variety of products – ranging from audio equipment, engines, automobiles, household appliances, large structures, heavy rotating machinery, industrial process plants to aeronautical components.

Fatigue

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Machinery acoustics

 

The objectives of our consulting activities in the area of machine acoustics are the investigation of sound emission from machines, the generation of meaningful acoustical specifications for machines, the development of measures to satisfy specific acoustic requirements and aiding clients in making structural and acoustical improvements to machines.

Sound emission measurements
Müller-BBM is an accredited testing laboratory for sound emission measurements, in compliance with current standards and regulations. Using appropriate standardized procedures we investigate sound emissions from machines at the locations where they are used - in the manufacturer's plant or in our laboratory. Müller-BBM’s facility in Munich includes a reverberation room as well as an acoustic anechoic chamber for making free space measurements.

Acoustic specifications
Based on the acoustic requirements for a machine, Müller-BBM can generate acoustic specifications for individual components of any desired type of product; including vehicles, office equipment and industrial process facilities. We consider our task maximize our customer’s benefit and to achieve the best possible result for the overall system.  This is solved by setting realistic technical requirements for the individual components, given the current state of noise reduction technology and considerations of cost optimization.

Developing noise reduction measures
Machines are often designed for optimum functionality, rather than for minimum noise and vibration generation. Müller-BBM Scandinavia advises on how to implement structural modifications on machines in order to improve their acoustic and Vibro-acoustic properties, all in favor of a quieter and more efficient machine.
However, even with a machine that produces the lowest noise allowed by its operating principle and efficiency requirements, it may be necessary to employ secondary sound reduction measures in order to adapt the machine to meet the local safety and environmental objectives. Such measures may include e.g. sound absorbers, mufflers and/or enclosures. Müller-BBM can propose suitable measures and can also develop special solutions. In addition, we can make our own test facilities available for acoustic measurements of e.g. sound absorbing materials and wall panels.

 

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Machinery dynamics & pulsation

 

High levels of structure-borne or airborne sound emissions may lead to damage within a facility or disturb operating processes. The root cause of the problem may for instance be resonant phenomena or broad band excitations in piping, burners, valves, furnaces or heat exchangers. The damage caused by vibrations can be evaluated, and measures taken, using standard damage accumulation hypotheses combined with structural-dynamics analysis and testing.

 

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Piping vibration

 

 Piping vibration can be an annoying problem which can consume unnecessary maintenance activity and may affect overall system performance and endurance of a system. The system includes the pipe, all piping supports, hangers, snubbers, valves, pipe to pipe interfaces, and machinery or devices attached to the pipe. All of these items can influence the pipe vibration patterns.

“On site testing” will determine the piping system vibration amplitudes, frequencies, nodal points, and the pipe modal shape. Extensive test on-site may also be used to identify defective supports, incorrectly placed supports, and the locations of maximum deflection requiring additional supports.

Additionally, Computer Aided Engineering (CAE) may be a powerful tool used to increase the understanding of the system behavior and to evaluate the effects of system changes.

 

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Structural dynamics

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Torsional vibration

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Psychoacoustics

 

“What you see is what you get” is a common expression. However, when it comes to sound “what you hear is not always what you get”. This is the beauty of psychoacoustics. A good example of this is the mp3-format that compresses audio files into next to nothing without the human brain hardly being able to separate the compressed sound from the original full scale recording.
The essence of psychoacoustics is that signals that are picked up by your ears doesn’t automatically mean that your brain is hearing the same sounds the way they first entered your ears. One might say that the brain acts as a signal processor with limited bandwidth. It simply cannot grasp all of the information that enters. In order to explain and understand how the brain interprets and reacts to sound we use psychoacoustics.
No small physical apparatus possesses properties more remarkable than those of the ear. It can withstand the most intense sounds produced by nature, while at the other extreme it responds to sound pressures that at some frequencies produce a displacement of the ear drum of 0.1 nanometer. This distance is less than one tenth the diameter of a hydrogen molecule!
So the hearing mechanism is, apart from being an extremely sensitive microphone with enormous dynamic range, also a signal analyzer and processor with considerable selectivity.
Take for instance the ears ability to sort out irrelevant background noise. If you have stayed late at work sometime you probably have noticed the relaxation and quietness when the air ventilation fans in the room shut down. But you may recall that just prior to the shut down you didn’t spend one second reflecting over the background noise - because your brain filtered out the background noise as irrelevant information.
Our hearing has many other filtering functions - most of them quite brilliant for life in the nature, but some not so brilliant in the modern, industrialized community. Nowadays, many man-made sounds are harmful to our hearing.
By improving our understanding of how the human hearing works, we can protect ourselves and our surroundings by creating smarter and more pleasant product sounds that catches our proper attention at the right time.
For instance, a car producer might want to send a message to their customers that their car is of good quality. By applying various psychoacoustic criteria and parameters we may quantify sounds associated with good quality, or soft/strong for that matter. All this because during our lifetime we have collected a library of sounds associated with happenings and materials.

Müller-BBM Scandinavia and our affiliated companies have extensive experience and competence in the field of psychoacoustics and applications that utilize our magnificent hearing’s capability of “interpreting” sound. Müller-BBM Scandinavia offers you first class advice and consultation on the benefits of and how to give your product a certain acoustic signature.

 

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Mobile communication 

 

How do you communicate easily and comfortably at great distances? The answers to this question are many and often complex. At Müller-BBM we strive to fulfill the so called “orthotelephonic reference” when dealing with aural communication. A definition of the orthotelephonic reference is for example: “Two persons standing at a distance of one meter apart keeping a conversation at a comfortable level in a noise free environment”. The carrier of information during the conversation may be air, electricity or light and each separate component in the signal chain is important to us in order to serve the underlying purpose, good communication, in the best possible manner.

Terminals
Müller-BBM can assist you in assessing and producing acoustically optimized telephone terminals such as:
• Mobile phones
• Portable office or residential phones
• Conference telephones
• Intercom devices

Networks
Müller-BBM can assist you in testing your device in controlled and simulated network environments for:
• GSM / GPRS / EGPRS
• WCDMA / CDMA (UMTS)
• TDMA
• AMPS
• BLUETOOTH
• WLAN 
• VoIP 
• DECT

Safety aspects and car phones
Müller-BBM investigates the different aspects of mobile communication whilst driving. On one hand there is quality of speech and speech intelligibility and on the other, safe driving. Is it possible to communicate with someone on the phone in a safe manner whilst driving your vehicle?

 

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Copyright 2007 by Müller-BBM Scandinavia AB