Sound power emission measurement and control on a 300-t hydraulic press

The paper summarizes the results of research work carried out to evaluate properly the noise emission characteristics of a 300-t hydraulic press in a complex noise propagation environment. On the basis of the collected data, some control measures were designed, and the results are discussed. As well known, noise is widely affected by the acoustical environment the sound propagates through, and an effective description of the source emission properties is required for the control design. Traditional measurement techniques are not the best for this purpose, because the information on acoustic pressure depends on the environment. To overcome this problem, the emitted acoustic power was then evaluated by means of acoustic intensity measurements; in such a way it is possible to qualify real and complex sound sources, locating the contribution of single parts that participate in sound generation. Resulting maps describing the contribution of every single part, an effective individuation of improvement strategies was possible, since the priorities for intervention were available. A new campaign of sound intensity measurements confirmed the expected control measures’ results, and the direct measurements of the operators’ exposure confirmed the success of the intervention.