【作者】 贾晓晨；

【导师】 王应吉；

【作者基本信息】 吉林大学 ， 电力电子与电力传动， 2009， 硕士

【摘要】 根据对核磁共振找水仪实验系统的要求及对核磁共振找水仪的室内实验环境电磁噪声进行分析,设计出一种能够在室内模拟野外实验条件,在一定程度上检测仪器功能是否正常的检测方法和装置。实现了在实验室内模拟野外条件,对核磁共振找水仪的性能指标进行测试和标定,加速了核磁共振找水仪野外噪声抑制等关键技术的研发,使每一台核磁共振找水仪在进行野外工作前进行充分地测试,以保证仪器野外工作的稳定性和可靠性,提高野外工作效率,降低野外工作成本。本设计包括核磁共振模拟信号发生器,屏蔽盒及上位机软件等几个主要模块。装置在室内产生核磁共振模拟信号,然后核磁找水仪检测经过衰减器和空间线圈衰减的信号,测得的数据送到上位机处理,将得到的结果同初始设置的关键参数进行对比,从而对核磁共振找水仪的放大器及采集模块的准确度进行调校。该装置进行过多次室内实验,可以实现长时间连续稳定工作,通过对实验结果的详细分析,验证了装置具有良好的稳定性和准确性。更多还原

【Abstract】 Water is one of the most valuable natural resources for the survival of human being. To solve the water crisis, high-tech investigation of groundwater has become an urgent task. Currently, the only direct detection of groundwater is the ground geophysical methods MRS. However environment electromagnetic noise (1 kHz to 3 kHz) influence the MRS water detector significantly, in particular in indoor detection. This paper firstly introduces the demands of MRS instrument for indoor detection and then analyzes the electromagnetic noise, to provide equipment that can detect whether the function of MRS instrument is normal and a detected method in the simulation of the field in the indoor experimental conditions. This equipment can detect and calibrate the MRS instrument system. The design includes some main module, such as analog MRS signal generator, electromagnetic shield box and upper computer software. First the equipment generates the analog MRS signal, then MRS instrument detects the signal that has attenuated by resistances and space coils. Finally the computer gets the data then compares results with the parameters that have set before; thereby we can proof the accuracy of the amplifier and collection cards.This thesis included seven chapters and it introduces the indoor detection and calibration equipment in detail.Chapter 1 is the introduction. Firstly, stated the theory of magnetic resonance sounding (MRS). Secondly, it analyzed the development of domestic and overseas researches, finally gives the content and meaning of the paper.Chapter 2 is the design of the overall structure of the indoor detection and calibration equipment. The overall design scheme of the equipment is given according to the function. Chapter 3 is the design of the analog MRS signal generator. It stated the design of the main chips interface, memory address assignment, and communication module and communication protocol in detail.Chapter 4 is the design of the electromagnetic shield box, it introduced characteristics of the electromagnetic shielding, choose of shielding material and design of the inter frame. At last it gave the tests of electromagnetic shield effect.Chapter 5 is the design of the upper computer software. It mainly stated the function of upper computer software, the design thought and the operation of software.Chapter 6 is mainly about a lot of indoor tests for the self-detection mode, the key parameters calibration mode, and the testing capacity of amplifier and collection cards. Finally, analyzed and explained the results of tests.Chapter 7 is the conclusion of this paper, summarized the research and look forward to the future work.Through system testing, the indoor testing and calibration equipment prototype is normal working, stability and accurate measuring, which achieved the expected objective of the basic design.更多还原