| Water is the most valuable natural resources for the survival of mankind. To solve the water crisis High-tech investigation of groundwater has become an urgent task. Currently, the only directly detection of groundwater is the ground geophysical methods NMR (SNMR). However 1 kHz to 3kHz environment electromagnetic noise influences the NMR water detector significantly. In this paper, the electromagnetic noise in the environment can be advancely estimated, and analysing the fixed electromagnetic noise interference of NMR water detector. This paper provides the reference of The design of this equipment ,and at the same time the noise signal collected by the noise tester can also provide some noise parameters. Install the test loop on the ground with square shape and connect the analyser to the test loop by the cable supplied.This thesis includes sixs chapters and it introduces the environment electromagnetic noise tester in detail.Chapter 1 is the introduction. Firstly, introduces the system of environment electromagnetic noise tester. Secondly, it introduces the correlation SNMR technology. Analyzed the development of domestic and overseas research, finally gived the content and meaning of the paper.Chapter 2 introduced the design program of environment electromagnetic noise tester. Firstly,analyzing the system detaily, and present the collectivity design scenario on several aspects ,including the system analysis, the system structure, the function modules division, the development network and communication process .Chapter 3 Analysised the hardware of the system,including the preamplifier and Acquisition card, the preamplifier analysised the electromagnetic field and the electromagnetic wave. On this basis, discussed the preamplifier design. Subsequently, the preamplifier on the shielding box design, analysis results are given. The acquisition card introduces the Acquisition card of this system,and the analysis results are given .Chapter 4 The upper support monitoring system software: A comprehensive account of the control and analysis of the function and use of software.Chapter 5 mainly about a lot of Field Tests, From the experimental results we can see that this equipment on the NMR water detector provide the coil options, as well as the choice of location and the correct analysis. Chapter 6 is the conclusion of this paper, summarizes the research and look forward to the future work.Through system testing, the environment electromagnetic noise tester system prototype is accuracy, good stability and self-adaptability, which achieves the expected objective of the basic design. |
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