| 摘要 |
FIELD: pipeline transport. ^ SUBSTANCE: method comprises repeatable sending pulse sounding acoustical signal into the pipeline section to be checked, converting the received acoustical signals into electrical signals, strobing and filtering the signals to extract valid signal, amplifying the valid signal and measuring its amplitude, storing the magnitude of the amplitudes of N of the valid signals, analyzing the valid signals, and generating the signal indicating the presence of cleaning device when the value of the amplitude of N valid signals is initially lower than the threshold and then monotonically increases during a specific interval of time and becomes higher than the threshold. ^ EFFECT: enhanced reliability. ^ 3 dwg |
