| 摘要 |
FIELD: physics. ^ SUBSTANCE: lay-on longitudinal oscillation pickup is placed on pipe to input digitise natural noise signal of gas flow into computer memory for sufficiently long time interval that comprises reflections from pipe imperfections separated by time delays to, then, compute recorded signal autocorrelation function via successive shifts of initial signal in discrete steps, within reflection time delay, for maximum probing distance. Note here that coordinates of defects are defined from position of autocorrelation function maxima on time axis, while defect classification is estimated from correlation maximum amplitude, duration and shape. ^ EFFECT: detection of various inhomogeneities, increased probing range. ^ 3 cl, 1 dwg |
