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Solid particle leakage detection in double-wall pipes is industrially important,especially in chemical and petroleum engineering.Here,we developed vibration and acoustic sensor approaches for the character-ization and comparative study of the applicability of leakage sand particle detection from the flow of gas pipes.A specific wideband vibration sensor and pressure-field microphone were selected to identify the vibro-acoustic characteristics within 50 kHz of the particle leakage.The vibro-acoustic time-behaviours and characteristic frequencies of particle leakage were observed by the time-frequency method.The leakage gas flow noise was verified by coherence analysis and minimized by a digital bandpass and band-elimination filter.Corresponding experiments were performed,and good agreement was found between the release pressures(0.1-0.3MPa)with different leak sizes(0-8 mm)under different sand masses(120 lm)and vibro-acoustic Root-Mean-Square(RMS)levels.In the comparison of the two meth-ods,the vibration method has a better frequency response for the leakage flow and is good for identifying whether there are particle leaks.The acoustic method has a time behaviour response and is good for establishing the relationship between the particle mass and signals.In addition,the acoustic method has frequency shift features with a better signal to noise ratio.The acoustic method lays the foundation for future work of more complex leakage detection combining the advantages of vibration and the acoustic method.