Product category:
Humidity and Environmental Sensors
News Release from: Bruel and Kjaer UK | Subject: Non-stationary STSF package Type 7712, version 2.0
Edited by the Engineeringtalk Editorial
Team on 06 September 2000
Software provides intuitive map of noise
problems
Brüel and Kjaer has launched a new version of its ground-breaking Non-stationary STSF (Spatial Transformation of Sound Fields) software system for measuring and analysing non-stationary sound fields
Sound and vibration specialist Brüel and Kjaer has launched a new version of its ground-breaking software system for measuring and analysing non-stationary sound fields The new Non-stationary STSF (Spatial Transformation of Sound Fields) package Type 7712, version 2.0, assists designers and manufacturers to comply with increasingly stringent noise standards and to better understand the noise radiation mechanisms of their products
Effective use of non-stationary STSF measurements can also reduce design time by pinpointing engineering changes and save measurement time to free test facilities for other purposes.
From one simple measurement, Non-stationary STSF can calculate any sound field descriptor such as sound pressure, sound intensity or particle velocity allowing users an unprecedented degree of optimisation of the sound-related features of their products.
Results are typically displayed as animated maps to illustrate how a specific property changes as a function of time.
By displaying the radiated sound as a contour plot or an animation directly on top of a picture of the object under test, Type 7712 provides an intuitive map of noise problems that can be understood even by non-acoustic engineers.
Non-stationary STSF Type 7712 includes special averaging and filtering functions to support detailed analysis of sound from engines.
For example, it is possible to average over shaft angle in order to relate the specific sound sources to the operating cycle of the engine.
Results can also be filtered to either fixed frequency bands, order bands or fractional octave bands.
With Non-stationary STSF it is possible to assess and locate noise sources accurately during a true run-up instead of approximating using successive stationary conditions.
This typically gives misleading results for noise radiation due to varying load conditions on many engine components.
Type 7712 can also analyse highly transient and non-repetitive noises such as those generated by office machinery and car brakes.
A single event can be recorded and analysed later with a time resolution down to one sample of the recording.
New features in Non-stationary STSF version 2.0 include: built-in time/frequency analysis to identify critical frequencies, orders or events prior to holography; order filtering to support analysis of run-up or coast-down conditions; an instantaneous active intensity function to accurately track moving sources and sources that come and go; separate licences for measurement, analysis and viewing to better support specialised working functions and data storage functions to make back up and use of historic data even easier.
With over 50 years experience, Brüel and Kjær is a world leading manufacturer and supplier of sound and vibration products for use in a wide range of applications including environmental noise measurements, building acoustics, vibration measurements and quality control for use in the automotive, aerospace and consumer industries as well as by local authorities.
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