Sound Test

About Sound Test 

Analysis of Vibration: a quick and relatively inexpensive way to detect the presence of defects. The analysis based on the vibrational characteristics of the product concerned is used to detect cracks, porosity, incorrect heat treatment, machining errors in multiple products and components.

The theoretical foundations upon which the Sound Test is based:

  • Each piece, when solicited, vibrates according to frequencies that uniquely characterize it
  • The presence of defects partialy alters the properties of the workpiece and generates differences in some points of the spectrum of frequencies
  • Comparing the “frequency response” of each product with that of a reference product, definitely free of defects, it is possible to detect any deviations.

Control techniques NDT (Non Destructive Test) based on the Sound Test have been successfully applied to:

  • Search defects in sintered parts even at the green state (gears, pulleys, rotors)
  • Control of brake pads integrity
  • Checking integrity of cast parts (brake discs, clutch plates, nuts and bolts)
    forged material
  • Control of welds integrity (cable terminals)
  • Checking integrity of refractory products and ceramics

The most evident advantages of the application of this technique are:

  • The cost is significantly lower compared to other control techniques
  • The test cycle has a duration of ca. 0,5 sec.
  • It can be applied at the end of the production line (by considering only the higher frequencies, the effects of background noise in production environments are avoided)

How does the Sound Test work?

  • The piece is stimulated to vibrate by drop or impact
  • A microphone captures the sound
  • The spectrum of frequencies generated from the workpiece is acquired by the MG-ST-100 system
  • Trying with an adequate number of pieces definitely good, a unique profile is generated
  • A piece not good reveals some deviations from the spectrum of the good one
  • MG-ST-100 compares and points out the anomaly