Imaginary Sound Intensity Test System Development

In this dissertation, the available sound intensity instruments are dissected, the development tendency of the sound intensity measurement and analysis (SIMAS) is predicted and a SIMAS using cross-spectral method based on a microcomputer, DASP software and the Microsoft Windows platform is developed.Use of sound intensity measurement noise is a more effective than other methods, particularly the use of dual-microphone made up for past noise measurement subject to environmental constraints defects and greatly reduce the cost of test and measurement.Test data collected ASCII code for the first conversion, and then to read ASCII files, processing, Measurement finished, we calculated each through the sound intensity measuring point value, then the cross-spectral summation through numerical analysis, signal processing, software analysis and curve fitting function so that we can further network will link the whole measurement will be outside of the mechanical, such as sound intensity and sound intensity map of the spectrum curves. Use of this software is produced sound intensity measurement analysis software. The software used by the programming language Visual C + + is its operating software the development platform is Microsoft Windows.In software development, first of all, for a scientific, practical, reasonable analysis, frame structures, according to the different functions I divide into the different modules. Second, the specific operation in order to facilitate switching between modules, we use the VC controls, to switch quickly and easily. It is particularly worth mentioning that in the process of developing a fully absorb more VC language interface functions and the creation of data-processing and graphics capabilities.In this paper the measures of diagnosis analysis for noise sources have been discussed according to the sound intensity measurement. The sound intensity measurement is carried out for the exterior radiation noise of an automobile and by means of spectrum and correlation analysis of noise signal, an investigation into the application of sound intensity measurement to noise control is presented. For the main noise sources of automobile-noise of the engines made a distinguish analysis technology and various noise control measures. It is beneficial reference to reduce noise of engine.