Frame leak testing, esp. of motor vehicle body - involves generating sound inside body and detecting and evaluating sound outside body

The leakage testing method involves producing (4-6) a defined sound level inside the body at one or more frequencies and detecting (7,8) and evaluating the sound signals occurring outside the body, esp. close to the body. Sound signal frequencies are produced in a frequency range below the resonant frequency of the body. In the case of motor vehicle bodies with a few cubic meters internal vol., sound frequencies between 20 and 60 Hz, pref. 40 Hz, are produced. The sound signals detected can be sound press., sound intensity and/or speed of sound signals. Sound impedance values can be derived or detected. USE/ADVANTAGE - Esp. for checking for correct mfr. and window and door sealing in vehicle. Method enables rapid, reliable testing.