Uncertainty analysis for the in situ sound power level determination using the substitution method
* Presenting author
Sound power determination at different environments and using different techniques exhibits deviations especially at low frequencies. In previous studies the establishment of traceability has been introduced and the realisation and dissemination of the unit watt in airborne sound has been discussed. For the completion of traceability, the sound power level determination of realistic sources is required. The contribution presents the application of the substitution method for the in situ sound power determination of real sources. The substitution method includes both sound pressure and sound intensity measurements. For collecting experimental data, different measurement methods were applied in various environments. Following the concept of traceability, the sound power level is accompanied by the related uncertainty, which explicitly explains the contributing factors along with their extent of contribution. A comparison is made between the uncertainty levels using sound pressure and sound intensity. The proposed uncertainty covers a wider frequency range compared to the up-to-date standards.