Research on sound intensity probe whose frequency band can be adjusted

The distance of microphones in sound intensity probe have great relations with effective sound frequency band measured during measuring sound intensity,. To adapt different measured frequencies, the position of every microphone in sound intensity probe should be adjusted. On the basis of discussing the theory of measuring sound intensity with four microphones from three dimensions, using the theory about keeping place of brace framework and parallelogram, we designed a new 3D sound intensity probe including four microphones. Because space among different microphones in sound intensity probe can be adjusted, it can choose appropriate measurement bandwidth according to the range of sound frequencies measured actually. 3D sound intensity probe with four microphones, whose measurement frequency can de adjusted, retained original advantages of 3D sound intensity probe, and overcome the shortcomings of measuring fixed bandwidth.