According to the NOMAD study 80% of the noise emission declarations of machines, demanded by European directives, were not reliable. Possible causes are, among other things, the high costs and the complexity of the normative measuring methods for the noise emission characteristics. For small and medium-sized enterprises (SMEs), self-performed measurements in their own premises would be a cost-effective alternative. These often fail due to the necessary determination of the environmental correction of the room in which these measurements are to be carried out. Within the framework of the project outlined, a simple method for determining the environmental correction, which is practicable for SMEs, is to be developed.
A possible method for qualifying the measurement environment works with the help of a reference sound source (RSS). The idea of the project is to replace this expensive RSS with a small, portable machine (e.g. industrial vacuum cleaner, compressed air compressor), available in every company, and to determine its sound power according to a noise test code in the acoustic free field, approximated by a free parking lot at low background noise. Subsequently, this replacement RSS is brought into the room, in which in the future all machines of the manufacturer shall be measured, and its sound power is measured there again. Since the noise power level determined there is higher because of the sound reflections in the room, the ambient noise correction of the measuring chamber is obtained from the difference between the two sound power levels.
Unit 2.2 "Physical Agents"