Velo Software

Acoustic Camera software

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The Acoustic Camera software is developed for array applications of multiple probes. This multiple probe solution, called Near Field Acoustic Camera, makes it possible to measure non-stationary (time wise) conditions and locate transient noises like squeak, rattle or clicking noises. The biggest advantage of using a Microflown sensor array over other solutions, is its ability to locate sound sources even at frequencies, as low as 20 Hz. In fact the sound source localisation had never been as easy before – the near field acoustic camera covers a bandwidth from 20 Hz up to 10 kHz, making it the only solution capable of locating sound sources regardless of frequency. The outcome of a measurement with the Acoustic Camera system is an acoustic picture presented in a form of a movie. The system is able to perform all calculations and sound field visualisations in real-time. Naturally, if the acquired data was recorded, extensive post-processing functions are just one click away. While using the system, you will be able to measure and visualise the distribution of:

  • Particle Velocity
  • Sound Pressure
  • Sound Intensity
  • Sound Power

The Acoustic Camera software will allow you to process your data using two sound field visualisation techniques:

  • Near field acoustic holography (NAH)
  • Direct sound visualization (DSV)

Direct sound visualisation

This method is based on direct measurements of Sound Pressure and Particle velocity in the acoustic nearfield, at discrete sensor locations. The combination of multiple probes, that form an array, allows for measurements under non-stationary (time wise) conditions, thus enabling localization of transient noises like, squeak, rattle or clicking noises.  The method has no frequency limitations, being usable in the full acoustic bandwidth (20 Hz to 10 KHz).

The outcome of a measurement with the Acoustic Camera system in conjunction with the direct measurement method, is an acoustic picture presented in a form of a movie. Such a movie can represent the spatial distribution of particle velocity, sound pressure, intensity, sound power or transfer functions between all channels. The acoustic movie is calculated by measuring sound pressure and particle velocity at several locations on the surface of the sound source. All data, provided in between the sensor positions is obtained by means of interpolation.

Near-field acoustic holography (optional)

The acquired data can also be processed using the Near Field Acoustic Holography method, which is implemented as an additional processing module within the Acoustic Camera software. This method applies a model of the source propagation to estimate its response at a certain, user defined, distance. This distance can be different than the plane where the actual measurements were taken. Furthermore, the NAH provides a much higher spatial resolution whilst working with the same amount of transducers (as compared to the direct method). Results obtained with the NAH provide a more smoothed description of the noise field (acoustic movie), and thanks to the characteristics of the mathematical models involved, the possibility of loss of information due to spatial aliasing is greatly minimized.

Furthermore, thanks to the ability to work with a variety of reference sensors (tachometers, current/voltage sensors, microphones, accelerometers) you can get a clearer overview about the relation between the noise emission and specific operating states of the objects under test. For applications involving rotating machinery the system is equipped with an extensive order analysis module, allowing you to extract the rotational orders both with and without a tacho sensor.

The software itself is a part of the Microflown Velo software platform. Thanks to the properties of the Microflown PU probe, all sensor arrays can be configured freely, without the need to preserve a defined spacing between all transducers in an array.  The software is equipped with all tools necessary to configure a user defined array. The array grids that can be defined in the software can be linear, irregular or even scattered, thus allowing to accurately measure curved surfaces and complex geometries. Furthermore, on the hardware side, we strive to support all types of applications along with tools necessary for proper sensor positioning. Microflown arrays can be delivered as custom, application specific, hand held grids, or with a flexible positioning system, as well as surface mounted sensor fixtures. 



  •  Velo 3B | Acoustic Camera





  • FFT
  • RPM - Tacho input
  • Order tracking
  • Overall vs Orders
  • Linear, Irregular and scatterd arrays
  • Audio and Video recording
  • Sound pressure dB & dBA
  • Particle velocity
  • Sound intensity
    • Active
    • Reactive
    • Possitve
    • Negative
  • Narrow Band
  • Octave
  • 1/3 Octave
  • 1/12 Octave
  • Extraction of the colormap tools
  • Frequency filtered playback of audio
  • Frequency and Time domain
  • Auto range
  • Import of Universal files (.unv)
  • Export to Time Files, MS Excel  & TXT
  • Export video to avi
  • Report function