1997
Acoustic emission (AE) generated by the feeding of worker termites, Reticulitermes speratus (Kolbe), were detected from wooden construction members of a traditional Japanese warehouse. The AEs detected by piezoelectric sensors with a resonance frequency of 150kHz were amplified about 66dB, filtered through a high-pass filter of 100kHz, and discriminated at a threshold voltage of 0.1V, and the AE activity was estimated by number of Aces counted for 10 min. Living termites in the galleries inside the beams were found near each detection point of AE by boring inspection. Neither AE nor evidence of swarming was detected after the attack points were treated with termiticide. AE monitoring as a nondestructive method for the detection of termite attack in actual wooden houses was feasible.
Traditional Japanese warehouse investigated
Setup of AE sensor
Distribution of measuring points and detected
AEs
filled circles: Points detected significant
number of AEs (Living termites in the galleries
inside the beams were found near each detection
point of AE by boring inspection)