本文選題：氣相色譜 + 對(duì)數(shù)運(yùn)放　； 參考：《西安電子科技大學(xué)》2015年碩士論文

【摘要】：近年來,氫火焰離子化檢測器(FID)在氣相色譜領(lǐng)域應(yīng)用越來越廣,FID具有很多優(yōu)異特性,在檢測器領(lǐng)域中具有良好的應(yīng)用前景。本文作者在江蘇天瑞儀器實(shí)習(xí)的過程中對(duì)FID的各個(gè)功能模塊進(jìn)行了系統(tǒng)的研究,包括信號(hào)采集部分、高壓模塊設(shè)計(jì)及點(diǎn)火電路。本文首先針對(duì)FID在氣相色譜質(zhì)譜聯(lián)用儀上的具體應(yīng)用提出了一些使用和操作上的注意事項(xiàng)。通過對(duì)電極形狀和噴嘴內(nèi)徑及材料的選擇可以提高它的靈敏性。此外,我們可以通過其結(jié)構(gòu)和操作兩方面的因素來提高有機(jī)物的離子化程度和集電極對(duì)離子的收集效率。在信號(hào)采集部分,基于原來采用的比例運(yùn)放,我們引入了對(duì)數(shù)運(yùn)放的思想。對(duì)數(shù)放大器兼具線性性質(zhì)和信號(hào)放大特性,避免了比例運(yùn)放要根據(jù)出峰情況手動(dòng)調(diào)整放大倍數(shù)的缺陷。最后針對(duì)FID中的實(shí)際信號(hào)采集放大電路進(jìn)行了仿真,仿真之后得到的結(jié)論和理論上推倒的數(shù)值基本吻合。對(duì)于加在離子室集電極的高壓,我們利用電容二極管倍壓電路設(shè)計(jì)實(shí)現(xiàn)了300V的高壓。首先對(duì)倍壓原理進(jìn)行了詳細(xì)闡述,然后對(duì)FID高壓電路進(jìn)行了Multisim電路仿真。最后我們利用開關(guān)電源控制點(diǎn)火絲上的電流,使其達(dá)到了自動(dòng)點(diǎn)火的功能。通過對(duì)開關(guān)電源BUCK電路的深入理解和總結(jié),設(shè)計(jì)了輸出濾波電感和電容值,最終實(shí)現(xiàn)了點(diǎn)火絲上的額定電流輸出。
[Abstract]:In recent years, hydrogen flame ionization detector (FID) has been widely used in the field of gas chromatography. During the practice of Tianrui instrument in Jiangsu province, the author has carried on the systematic research to each function module of FID, including the signal collection part, the design of high voltage module and ignition circuit. In this paper, the application of FID in gas chromatography-mass spectrometer is discussed. The sensitivity can be improved by selecting the electrode shape, nozzle inner diameter and material. In addition, we can improve the degree of ionization of organic compounds and the efficiency of collecting ions by the structure and operation of organic compounds. In the part of signal acquisition, based on the original proportional operational amplifier, we introduce the idea of logarithmic operational amplifier. The logarithmic amplifier has both linear property and signal amplification property, which avoids the defect that proportional operational amplifier should manually adjust the magnification according to the peak condition. Finally, the actual signal acquisition and amplification circuit in FID is simulated, and the simulation results are in good agreement with the theoretical values. For the high voltage of ion chamber collector, a 300V high voltage is designed by using capacitive diode voltage doubling circuit. Firstly, the principle of voltage doubling is described in detail, and then the simulation of FID high voltage circuit based on Multisim is carried out. Finally, the switch power supply is used to control the current on the ignition wire, which makes it achieve the function of automatic ignition. Through the deep understanding and summary of the buck circuit of switching power supply, the output filter inductance and capacitance are designed, and the rated current output on the igniter wire is finally realized.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TH83;TN702

【參考文獻(xiàn)】

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本文編號(hào)：2064702