摘要
本文从井下超声电视声系出发,详细分析和推导了回波时间检测门限的理论模型,设计了一种自适应门限网络,使检测门限电平能随着噪声电平和换能器的余振而变化.实践证明,这种技术对于克服由换能器余振干扰、信号大范围起伏造成的时间检测困难十分有效.
A theoretical model for the echo time detection threshold has beem developed.The circuit layout for realizing the adaptive threshold and making the threshold level vary with both the noise level and the residual oscillation of the transducer is presented. Experimental results show that the technique proposed is effective for overcoming the difficulty in time detection resulting from the disturbance of residual oscillation and wide fluctuation of signal amplitude.
出处
《华中理工大学学报》
CSCD
北大核心
1991年第A01期29-34,共6页
Journal of Huazhong University of Science and Technology
关键词
井下
测井仪
自适应门限
超声电视
Borehole televiewer
Time detection
Adaptive threshold
