本文選題：便攜式 + 氣相色譜��； 參考：《合肥工業(yè)大學(xué)》2016年碩士論文

【摘要】：氣相色譜技術(shù)在分析化學(xué)領(lǐng)域內(nèi)占據(jù)著重要的地位。因其具有對復(fù)雜混合物進(jìn)行分離和檢測的能力,使之在石油、化工、農(nóng)業(yè)等行業(yè)都有著廣泛地應(yīng)用。近年來,農(nóng)藥殘留檢測等現(xiàn)場檢測工作日益增多,而傳統(tǒng)的氣相色譜儀由于結(jié)構(gòu)復(fù)雜,體積較大難以滿足現(xiàn)場檢測的要求。因此,便攜式、微型化已經(jīng)成為氣相色譜技術(shù)發(fā)展的一個重要趨勢。而溫度控制系統(tǒng)是整個氣相色譜控制系統(tǒng)的核心,因此,溫度控制系統(tǒng)的微型化研究是便攜式氣相色譜儀研究開發(fā)的重點(diǎn)之一針對這一問題,本文設(shè)計了兩種微型化的色譜柱加熱方式：一種是使用3D打印技術(shù)制作的小型色譜箱對色譜柱加熱的方式,另一種是通過不銹鋼毛細(xì)管直接對色譜柱加熱的方式。本文針對第一種加熱結(jié)構(gòu)設(shè)計了一種基于Micro2440控制板和Linux系統(tǒng)的嵌入式微型化溫控系統(tǒng)。這種控溫結(jié)構(gòu)既精簡了溫控電路又縮小了溫控系統(tǒng)硬件所占的空間。該控溫系統(tǒng)的主要硬件為Micro2440主控制板,以及集成在其內(nèi)部的三路ADC轉(zhuǎn)化器與三路GPIO輸出接口。三路ADC與GPIO分別應(yīng)用于進(jìn)樣器、毛細(xì)管柱加熱箱以及檢測器的溫控。溫控的主要過程為主線程通過ADC從溫度采集模塊得到當(dāng)前溫度,然后根據(jù)該溫度值經(jīng)過PID算法計算出本次加熱時間并通過設(shè)置GPIO來執(zhí)行加熱。本文所采用PID控制算法是單神經(jīng)元加PID的算法,并采用有監(jiān)督的赫布規(guī)則來動態(tài)修正PID算法中的比例、積分及微分系數(shù)。最后,通過升溫實(shí)驗(yàn)結(jié)果表明,本文設(shè)計的氣相色譜溫控系統(tǒng)控溫精度能達(dá)到±0.5℃,并實(shí)現(xiàn)了程序升溫功能。而搭載這種溫控系統(tǒng)的便攜式氣相色譜儀,在實(shí)驗(yàn)室環(huán)境下成功地檢測出了敵敵畏、敵百蟲等有機(jī)磷混合物。
[Abstract]:Gas chromatography plays an important role in analytical chemistry. Because of its ability to separate and detect complex mixtures, it is widely used in petroleum, chemical, agricultural and other industries. In recent years, the field detection work such as pesticide residue detection is increasing day by day, but the traditional gas chromatograph is difficult to meet the requirements of field detection because of its complex structure and large volume. Therefore, portable and miniaturization has become an important trend in the development of gas chromatography technology. The temperature control system is the core of the whole gas chromatography control system. Therefore, the miniaturization of the temperature control system is one of the key points in the research and development of portable gas chromatograph. In this paper, two kinds of micro-column heating methods are designed: one is a small chromatographic box made by 3D printing technology to heat the column, the other is the direct heating of the chromatographic column through stainless steel capillary. In this paper, an embedded miniaturized temperature control system based on Micro2440 control board and Linux system is designed for the first heating structure. The temperature control structure not only simplifies the temperature control circuit but also reduces the space occupied by the hardware of the temperature control system. The main hardware of the temperature control system is the Micro2440 main control board, as well as the three-way ADC converter integrated in its interior and the three-way GPIO output interface. Three-channel ADC and GPIO are used in temperature control of sampler, capillary column heating box and detector, respectively. The main process of temperature control is to get the current temperature from the temperature acquisition module by ADC. Then the heating time is calculated by PID algorithm according to the temperature value and the heating time is executed by setting GPIO. The PID control algorithm used in this paper is a single neuron plus PID algorithm, and the supervised Herb rule is used to dynamically modify the proportion, integral and differential coefficients of the PID algorithm. Finally, the experimental results show that the temperature control system designed in this paper can achieve 鹵0.5 鈩，

本文編號：1947528