Implementation of non-destructive test for wall hollowing based on virtual instrument technique

In view of defects in methods used for testing wall hollowing, this paper puts forward the testing scheme for hollowing in wall or ground on the basis of analyzing the physical process generating the knocking acoustic signals. It also designs the system for testing the quality of wall or ground based on virtual techniques. The system can determines the quality defects occurring in wall by testing the surface of buildings and analyzing the spectra. The practical experiments on samples of both solid and hollow and the experimental results are given. The results show that each function of the testing system proposed in this paper reaches the technical requirements of non-destructive test for wall hollowing.