- Project number: F 2571
- Institution: Federal Institute for Occupational Safety and Health (BAuA) / Physikalisch-Technische Bundesanstalt (PTB)
- Status: Ongoing Project
- Planned end: 2027-08-31
Description:
Noise emissions from machinery are the main cause of noise hazards for employees. In order to combat this hazard at source, the Machinery Directive stipulates that the main parameter of noise emission, the sound power level, must be specified.
The sound power level is measured in accordance with around 10 internationally harmonised measurement standards, some of which require special laboratory environments (reverberation rooms, hemi-anechoic chambers) or complex measurement techniques (reference sound sources, intensity probes, etc.). This high level of effort is considered to be the main reason why, despite legal requirements, the noise data for 80 % of the machines were not reliable or not available at all (NOMAD study (2012)). Measurement with a sound pressure microphone on an enveloping surface in accordance with EN ISO 3744 requires the least effort in comparison, although this standard requires the use of a certain number of fixed measurement positions. This number must also be increased if the source emits sound in a directional manner.
The aim of the project is to develop a method for measuring the required surface averaged sound pressure level by continuous scanning, e.g. manual scanning. In particular, the effects of shifting the scans into the near field of the sound source are to be investigated. The main focus here is on a practical compromise between measurement effort and measurement uncertainties. The project aims to develop a simplified and practicable sound power measurement method (draft standard), the application of which will make it easier for machine manufacturers to comply with legal requirements. Reliable noise emission declarations improve the conditions for implementing the "Sell and Buy Quiet" concept, so that employees are better protected against hazards caused by machine noise in the long term.