The acoustic properties of technical products are expressed in terms of sound power. Due to a lack of procedures for direct sound power measurement, the experimental determination of such quantities is currently based on the measurement of field quantities like sound pressure. Acoustic power can be calculated from the field quantities under restricting assumptions only. The failure of complying with them is the basic reason why different standardized procedures to determine sound powers give different results for the same measurand and why uncertainties easily reach several dB to date. One exemplary consequence following from this is, that it is often impossible to resolve discrepancies between defined legal requirements for noise protection and measurement results. This EMRP-JRP project (The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union) aims to establish traceability for the measurand sound power unit watt, thereby solving the problem of ambiguous sound power results.
In the project, there are 5 work packages (WP).
- WP1 will be dedicated to the development and experimental validation of a primary standard source for airborne sound power on the base of a baffled vibrating solid body.
- WP2 will aim at the dissemination of the unit watt by means of appropriate transfer standards.
- WP3 will focus on applications in machinery noise.
- WP4 is designed to maximise the impact of this JRP as described below.
- WP5 describes the management of the JRP.
TÜBİTAK UME took on the responsibility of the “dissemination of the unit watt by transfer standards” work package (WP2) and included all other work packages to perform researches and measurements. The results of this project will enable UME and other NMIs to set up primary sound power sources. From these sources, the unit watt will be disseminated by transfer standards to the user community which are laboratories from independent testing institutes and from industry and therefore the traceability of sound power unit will be provided by new improved reference standard.
(in progress)