Comparative analysis of the theoretical accuracy for two four-microphone probes in plane sound field

The sound intensity measurement accuracies of tetrahedral and orthogonal probes are compared according to the numerical calculations of relative probes' positions. The errors of amplitude and directional angle are also compared for the two probes under different conditions. The results show that the magnitude error of the tetrahedral probe is less than that of the orthogonal probe for plane wave in the frequency range of 1 to 4 kHz, but both are less than 1 dB, which means that the center of the circumscribed sphere has higher accuracy in amplitude at high frequencies. When f is less than 0.9, the error of the directional angle for the two probes can be controlled within 2°, and so they can be used in the architecture acoustical measurement.