| As sound intensity is a vector and the measurement is not affected by the near-field effect, it can be easily used to describe the sound-field characteristics and to locate the noise source. The sound intensity has been applied broadly in engineering since it can be tested on the spot.In this paper, the portable hardware system of sound intensity measurement & analysis has been developed by using an intensity probe B&K 3520, a power supply B&K 2804, a NI DAQ card 6062E as well as an amplifier designed by ourselves. Based on virtual instrument LabVIEW, the software of this system was developed. The measuring system is capable of measuring the sound pressure and to compute the sound intensity and to analyze the 1/3 octave spectrum. At last, using the disk mill FFC-23A as a noise source, the measuring system was validated by comparing the sound level measured by sound pressure meter ND2 with that measured by the system, the results show that the measuring precision of the system is less than 1dB, which is satisfy with the requirements of high quality measurement of sound intensity.The virtual instrument technique has been imported in the system of sound intensity measurement & analysis, in which some hardware functions were realized by software, it lowers the costs and increases the flexibility of the instruments, solved the problem in measuring the sound intensity on the spot.
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