【作者】 杜建华；

【导师】 苏秀苹；

【作者基本信息】 河北工业大学 ， 电机与电器， 2007， 硕士

【摘要】 超声检测是现代无损检测中重要的一部分,它广泛应用于石油、化工、冶金、造船、航空、航天等各个领域。目前,以超声波测厚仪测量管材和其它部件厚度,测量方法都是逐点测量,缺乏对整个管材连续测量的能力。多通道超声检测系统除了单通道超声发射仪的模拟量检测和处理系统外,还包括数字测定系统(时差测量装置)以及单片微机数据处理系统和外围显示系统。多通道超声波测厚系统其中通道数至少包含两个通道,但是通道数也不能过多,因为要考虑到测量探头的激励方式,由于所有通道的壁厚信号要经过同一个充放电电路和峰值检波电路,这样就要求这些通道在时间上不能并发,否则会造成壁厚脉冲的重叠从而造成测量错误。这是探头激励只能是串行方式的原因。探头只能依次激发,造成了测量速度不能过快。否则,在同一个探头相邻的两个激励周期内,测量点将相距过远而失去系统的连续测量能力。本文主要对超声波多通道实时在线测厚系统进行了以下几个方面的研究:研究了超声波的传播特性、超声波传感器测厚原理;建立了多通道测厚模型;研究了超声波多通道测量探头的分布及其触发方式;研究了数据的微机化处理方法,将被测参数经超声传感器换成模拟信号,再由模拟输入通道进行信号调理和数据采集,转换成微机要求的数字形式送入微机进行必要的处理,其中包括主机及其接口电路的设计、数据处理及其监控程序的设计等。更多还原

【Abstract】 Ultrasonic nondestructive testing is an important part of modern measurement, it’s widely used in petroleum, chemical industry, metallurgy, shipbuilding, aviation, aerospace and other fields. Currently, ultrasonic thickness gauge to measure the thickness of pipe and other components, the main measurement methods are measuring point by point. They are lack the capacity of continuous measurement for the whole pipe. Multi-channel ultrasonic thickness measurement system in addition to have single-channel ultrasonic instrument analog detection and treatment systems, which includes digital measurement system, as well as single-Tablet PC data processing system and the external display system. Multi-channel ultrasonic thickness measurement system at least includes two channels, but not excessive number of channels. In this system, the probe could only inspire one by one and so the measurement of speed is not very fast. Otherwise, in the same incentive cycle of the two adjacent probes, the measurement will be set too far apart and lost the capacity of continuous measurement. We should also study the sequence of ultrasonic probe and trigger frequency, etc.This subject will conduct a comprehensive study for multi-channel、on-line and real-time ultrasonic testing system. The main contents of the paper are: Study the thickness measurement principle for ultrasonic sensor, establishment of the multi-channel model; Study the trigger way and the distribution of probe in multi-channel ultrasonic measuring systems ; The research in computerized data processing. This thesis includes mainframe and its interface circuit research, data processing and monitoring procedures for design.更多还原