基于正交锁相放大器的交流电法接收机设计-中国测试.PDF

第41卷第9期 中国测试 Vol.41 No.9 2015年9月 CHINA MEASUREMENT TEST September，2015 doi院10.11857/j.issn.1674-5124.2015.09.014 基于正交锁相放大器的交流电法接收机设计 张 林袁 董浩斌袁 宋恒力 （中国地质大学（武汉）自动化学院，湖北 武汉 430074） 摘 要院针对目前野外测量环境复杂袁直流电法仪测试结果不稳定尧发射电流大导致野外使用不方便等问题袁提出 将相关检测技术用于低频交流电法接收机的设计方案遥 采用正弦波交流激发袁通过正交锁相放大器测量接收电极 上电位差信号的幅值和相位信息袁实现复电阻率的低频交流电法仪接收机设计遥 利用中心频率自动可调的带通滤 波器和频率自动跟踪的锁相放大器袁在强噪声背景下检测出接收电极上的电位差信号遥实验结果表明院在一定频率 范围内接收机实现频率自动跟踪测量袁准确测量出被测信号的幅值和相位袁提高电法仪的测量精度和抗干扰能力遥 关键词院交流电法曰锁相放大曰正交参考曰相位 文献标志码院A 文章编号院1674-5124渊2015冤09-0060-06 Design of AC electrical prospecting receiver based on orthogonal lock-in amplifier ZHANG Lin，DONG Haobin，SONG Hengli （Automation College，China University of Geosciences （Wuhan），Wuhan 430074，China） Abstract: A design plan of using a new inspection technology for low-frequency AC electrical prospecting receiver has been proposed in this paper to substitute the present DC electrical method that has unstable test results and large emission current when used in complicated field measurement environment. A low frequency AC electrical prospecting receiver with complex resistivity is designed through AC sine wave excitation and the measurement of amplitude and phase information of potential difference signal on a receiving electrode by an orthogonal lock-in amplifier. The receiver can detect potential difference signal of the receiving electrode under strong noise background with the help of an automatic frequency-tracking lock-in amplifier and a center frequency-tunable band-pass filter. The result shows that the receiver has implemented automatic fre