基于电容法的低氢型焊条药皮含水量检测系统研究与设计

发布时间：2018-05-14 06:15

本文选题：低氢型焊条 + 药皮含水量　；参考：《兰州理工大学》2017年硕士论文

【摘要】：快速、无损、在线的测定方法,对于低氢型碱性焊条药皮含水量的测量具有重要意义。本文提出一种新的基于电容法检测低氢型碱性焊条药皮含水量的测量方法,分析并验证了其测量原理。在此基础上,设计一种半封闭式圆筒状电容传感器,并对其结构进行了优化分析,得出传感器结构参数。依据国标GB5117-1995测量焊条药皮含水量的标准方法对所研制的电容式低氢型碱性焊条药皮含水量传感器进行标定,采用较常用的三种不同尺寸的J707低氢型碱性焊条作为该实验的实验材料,展开对该型号传感器的实验研究。实验结果表明,焊条药皮含水量在小于2.4%范围内,焊条药皮含水量与焊条药皮作为介质的电容器电容值具有较好的线性关系,并通过误差分析确定了该型号焊条的吸水饱和点。最后,基于该型号焊条的电容式焊条药皮含水量传感器设计了检测系统,测试了其检测性能,结果表明此系统符合焊条药皮含水量检测要求。该研究对焊条的无损、快速、现场可在线检测具有十分重要的应用价值。本文主要进行了以下四个方面的课题研究工作:(1)针对目前水分检测原理、技术和常用传感器,分析其测量原理,并对各种检测传感器进行对比分析和研究,提出一种新的电容式测量焊条药皮含水量的检测方法。(2)基于对传感器原理和传感器分类的分析,得出电容式低氢型碱性焊条药皮含水量传感器设计方案,并对其结构、测量原理、等效模型做了分析和计算,然后通过传感器应力分析和有限元分析对传感器结构参数进行优化,为传感器制作提供理论依据。(3)通过进行焊条药皮含水量的标定实验,测定了该传感器涉及到的各项性能指标,结果表明此传感器能够应用于焊条药皮含水量检测。在标定实验研究中,应用最小二乘法回归方程、多项式回归方程、一元线性回归方程三种误差分析方法,准确找到该型号焊条药皮吸水饱和点。(4)设计了电容式焊条药皮含水量传感器检测系统,分别从硬件、软件方面对系统做了详细的介绍。以单运放配合模拟开关构成差分充放电电容检测电路,实现了对传感器电容值的高精度检测。同时在软件上,设计出数字滤波器,提高了系统的检测准确率,减小了系统检测的误差。
[Abstract]:The rapid, nondestructive and on-line measurement method is of great significance for the measurement of water content in the coating of low hydrogen alkaline electrode. In this paper, a new method based on capacitance method is proposed to measure the moisture content of the coating of low hydrogen basic electrode, and its measuring principle is analyzed and verified. On this basis, a semi-closed cylindrical capacitive sensor is designed, and its structure is optimized and analyzed, and the structural parameters of the sensor are obtained. According to the national standard GB5117-1995 standard method for measuring moisture content of electrode coating, the developed capacitive low hydrogen basic electrode coating water content sensor was calibrated. Three kinds of J707 low hydrogen alkaline electrode with different sizes were used as the experimental materials. The experimental study of the sensor was carried out. The experimental results show that the moisture content of the electrode coat is less than 2.4%, and the capacitance of the capacitor with the electrode coating as the medium has a good linear relationship, and the water absorption saturation point of the electrode is determined by error analysis. Finally, based on the capacitive electrode coating moisture sensor, the detection system is designed and its testing performance is tested. The results show that the system meets the requirements of electrode coating moisture detection. This research has very important application value for non-destructive, fast and on-line detection of welding rod. This paper mainly carried out the following four aspects of research work: 1) in view of the current principle, technology and common sensors of water detection, the measurement principle is analyzed, and various kinds of detection sensors are comparatively analyzed and studied. Based on the analysis of sensor principle and sensor classification, a design scheme of capacitive low hydrogen basic electrode coating moisture sensor is proposed, and its structure is analyzed. The measurement principle and equivalent model are analyzed and calculated, and then the structural parameters of the sensor are optimized by the stress analysis and finite element analysis of the sensor, which provides a theoretical basis for the fabrication of the sensor. The results show that the sensor can be used to detect the moisture content of electrode coating. In the calibration experiment, three error analysis methods, least square regression equation, polynomial regression equation and univariate linear regression equation, are used. The measuring system of water content sensor for capacitive electrode coating is designed. The hardware and software of the system are introduced in detail. The differential charge-discharge capacitance detection circuit is composed of single operational amplifier and analog switch, which realizes the high precision detection of the capacitance value of the sensor. At the same time, the digital filter is designed in the software, which improves the detection accuracy of the system and reduces the error of the system detection.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212;TP274

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