| 摘要 |
A method and apparatus for screening wood poles to identify those in which rot or other deterioration has occurred to an extent which justifies a more detailed examination, comprises injecting "white sound" into the pole at 40Hz and measuring the amplitudes of vibrational energy at 100Hz and 350Hz opposite the point of injection. A comparison of the amplitudes of these frequencies is used to signify whether the pole has passed the screening. Two such tests are conducted at perpendicular positions on the pole. The screening apparatus may be combined with apparatus for conducting a more detailed examination of the pole if it fails to pass the screening test.
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