The Conditioning Circuit Design Of MRS Research Prototype

Water is the key element for life on the earth. It is the basic and important material for the people's daily life and the industrial and agricultural production. Humanity faced with survival water resource crisis. Thus, it is a urgent matter to detect the groundwater using high-tech. Currently, the only direct detection of groundwater is the ground geophysical methods MRS. Compared with the traditional methods, it has characteristics of unique explanatory of inversion,low cost and high efficiency. JLMRS-1 MRS instrument is researched and developed by Jilin University independent. It has been successfully applied in Jilin, Inner Mongolia and other areas looking for water projects. In engineering practice, faced to different environments and groundwater distribution, its amplifier has exposed some problems such as not flexible, poor anti-interference ability and so on. This paper is the amplifier improvement of MRS instrument. Blow is the main research activities include in this paper: by using the technology of smoothing relay switching to improve front-end of the receiver and reduce jitter and relay the impact of the NMR signal acquisition, improved the quality of the received signal. The MRS Larmor frequency distribution is analyzed, according to the magnetic field distribution in China. Improve the broadband filter of the MRS amplifier, narrowing the bandwidth of existing broadband filter, and produced a different center frequency band pass filter in accordance with the Larmor frequency distribution, enhanced MRS instrument of anti-jamming capability. Auto adjustment of amplifier gain, enhancing the flexibility of the amplifier and even a weak MRS signals reception. Build the amplifier database to automatically identify the amplifier board and the parameters of call based on PC- software. Resolve the amplifier hardware differences lead to different nuclear magnetic resonance instrument problem of poor compliance. Chapter 1 is an introduction. This paper describes the research background and significance, the content of its current development status and main contents of this paper and the frame structure.Chapter 2 is principles and problems analysis of MRS .Introduced the basic principles of MRS and some problems and issues to be taken for the four solutions of JLMRS-1 MRS instrument in the receiver's amplifier.Chapter 3 is about the amplifier improvement of MRS instrument. The chapter introduce the detail method of the smooth switching circuit of relay, the improvement of the broadband band pass filter, the amplifier gain auto adjusting technique and the one board one parameter method ( parameters of each amplifier is recorded and recognized by software used to configure the instrument).Chapter 4 is the testing result and the analysis. The result of the four improvements of the amplifier (smooth switching circuit of relay, the improvement of the broadband band pass filter, the amplifier gain auto adjusting technique and the one board one parameter method) are listed and analyzed.The last chapter is the summary of the whole paper and the further works to be carried out.The testing result shows that the improvement of the amplifier introduced in the paper is effective. The signal quality and the agility of the instrument are improved. Also, the consistency of different MRS instruments is also improved. The study of the paper will be the useful step for the product forming of our MRS instrument.