Sub-project 2: Improving the practicability of the sound intensity method
The NOMAD study demonstrated that about 80% of the noise emission data for machines, demanded by European directives, were not reliable. A possible cause is the high complexity of the normative measurement procedures for determining noise emission values. The sound intensity measurement procedure according to the DIN EN ISO 9614 series of standards is ideally suited for an in-situ determination of the sound power of machines, as it does not require a background noise and an environmental correction. "In-situ" means within an industrial environment, e.g. in a factory hall, and not in an acoustic test room. Larger machines and systems in particular can best be measured using these methods, as otherwise correspondingly large acoustic test rooms would be required. However, the standards of the ISO 9614 series no longer correspond to the state of the art in form and content. In addition, these standards require complicated calculations and the verification of field indicators. The scanning procedure, which is particularly suitable for large machines, is divided into two standard parts (ISO 9614-2 [accuracy classes 2 and 3] and ISO 9614-3 [precision process, accuracy class 1]), whereby only ISO 9614-3 is listed under the Machinery Directive. In this extramural research project, the standards are to be adapted to the current state of the art and the two scanning methods are to be combined in one part of the standard. In addition, further measures to improve the practicability and simplification of these standards are to be developed and tested in measurements as part of this project.
Unit 2.2 "Physical Agents"