Product noise

End-of-line acoustic test

Microphones in a hood or booth turn part noise into a sound level and band limits. Sound power is an option.

Get in touch All use cases
When it makes sense
The same noise check on every part

A hand-held meter works for one sample. It does not scale to full production:

Hardware
What the station uses
Hood or booth background noise controlled Part own function cycle Microphones signals analog samples stored limit check Signal conditioning IEPE or externally polarized Data acquisition NI DAQmx or Dewesoft, multichannel Industrial PC OpenEOL workflow Sound level and spectra, stored Pass or fail to PLC and MES Sound power ISO 3744, an option Your part Station hardware
The hood or booth holds the part and a fixed microphone array. The signal chain turns their output into a sound level, a spectrum and a pass or fail result.
The test
How the test works
  1. Close the part in the hood or booth, and run it through its function cycle.
  2. Record all microphone channels together.
  3. Calculate the A-weighted level and the octave and third-octave bands, and the sound power to ISO 3744 as an option.
  4. Compare the result with the limit, and store it with the serial number.
Software
The open-source software behind it
Your plantReceives the results
MES and quality databaseResults over OPC UA, MQTT or SQL
OpenEOLRuns the workflow
Task engine Open sourceRuns the acquisition and the limit check in order
GUI framework Open sourceOperator screens with live data and the result
Reports and database Open sourceOne sound level record for each part
AnalysisOpen-source tools in the workflow
Sound level Open sourceA, C and Z-weighted level, octave and third-octave bands
FFT and cross-spectral density Open sourceNarrowband spectra, and the base for two-microphone sound intensity
Limit checkPass or fail against the band limits
Sound power to ISO 3744Sound power from the same fixed microphone array
DriversTalk to the hardware
OpenEOL IO drivers Open sourceNI DAQmx or Dewesoft, multichannel analog input
Vendor runtimeNI-DAQmx from NI, when NI hardware is used
The parts marked open source are code your team can read and change. The limit check and the ISO 3744 procedure are written for each project, on top of the OpenEOL analysis functions.
Related use cases
Other noise tests

Sound power measurement without an anechoic chamber

A camera-based method that finds sound power with no test booth.

Blocked force measurement for motors and pumps

A noise source characterized once at its mounting points.

Fan end-of-line test rig

The same booth and microphone chain, added to a fan or blower test bench.

We can help
Planning a noise test station?

Get in touch.

janko.slavic@fs.uni-lj.si
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