Detection of termites with acoustic emission

Acoustic emission (AE) activity was measured under laboratory conditions from three species of termites in artificial galleries of dimensional white fir. Tests were made on the sensitivity of resonant transducers at a range of frequencies from 30 to 175 kHz, in which 60 kHz was found to be the most appropriate for high gain and minimum interference. A 1-week exposure at 25°C showed no periodicity of activity. When exposed to temperature cycles, the activity was reasonably constant between 10°C and 30°C. The detectability of dampwood termites, which had the highest level of activity, was up to 2.2 m in the grain direction.