The Establishment Of Noise Inspection Laboratoryfor Hvac System Instrucment

As one of the main environmental contamination like water and air pollution, noise pollution has been more noticed day by day. The noise effected human activities in a variety way. It reduces the service life of machines, put damages on the walls and windows of a building and a long-last noise can break the physical health of human. Therefore, studying of the generation, cancellation and control of noise is important for engineer. And the sound measurement is the foundation.Noise is a very complex physical quantity since it concerns the auditory sense. It’s difficult to evaluate compared with other engineering quantity. Even though we can choose an accurate one based on today’s technology, the evaluation still has quite a limitation. Audiometer is regular for sound measuring. But it’s designed to use a static average power to evaluate the dynamical sound which is farfetched. And there are variety kinds of interfering factors which make the results less accurate.In spite of all these "defects" happened during the sound measurement, we can still reach a reasonable sound level by considering all the important factors. And the key is choosing an appropriate measurement method based on the project.Firstly this paper introduced the background and significance of the sound-level measurement, clarified its importance and then the theoretical foundation. After that, we discussed the three representative methods of noise measurement based on engineering experience. And then we focused on the establishment of the laboratory and the experiments. We also put up with the unexpected factors during the inspection and the corresponding evaluation. Finally, a brief summary had been given about the noise reduction and the design of virtual radiometer based on Matlab.