实用水塔水位自动控制装置

近年来,电子报刊介绍了不少各具特色的水位自动控制电路,但很多电路仍采用浸在水中的电极式水位传感器。检测电极通直流电时极易被腐蚀,而改用通交流电的方法虽很大程度改善了电极被腐蚀的现象,但电极长期浸在水中难免附有污垢,也会影响检测灵敏度,严重时甚至导致控制失灵。另外,大多数水位自控电路长年通电工作,既浪费电能、也容易使控制电路产生故障。笔者向大家介绍一款实用的水位自控装置可克服上述缺点,该电路简单易制、造价低廉,很适合电子爱好者制作。工作原理:电路如图1所示。水位检测部分采用浮子     

高水位自动延时抽水装置

高低水位自动控制电路在许多电子刊物上均有介绍,但都有一个共同的缺点:即传感电极长期浸在水中并通有直流电,因处于电解状态,故时间一久电极就会腐蚀。尤其在污水里,水中的酸、碱盐等杂质较多,电极在短期内就会损坏,无法保证电路长期可靠工作。笔者介绍的电路,巧妙地采用了单结晶体管延时释放电路, 较好地解决了水池、水箱电极易损的问题。     

可靠的电极式水位自动控制电路

本文介绍的水位自动控制电路,电极上使用低压交流电,水中电解反应甚微。长期使用电解生成物不附着电极,电极不参与电解反应,因而与传统各种电极式水位自动控制电路相比使用寿命更长,性能更可靠。     

带水位指示的水位控制电路

一般水塔自动抽水控制电路均没有水位指示功能。使用中总有美中不足之感,为此,笔者设计制作了一控制器,其特点是:增设了水位指示功能以及采用555电路作末级控制,使抗干扰能力和可靠性大大提高,并且直观明了,很适合水塔距机房较远的场合使用。本电路分传感、控制两部分组成。传感电路是由六根插入水中的电极测出水位的高低,经ICl MN4069转换成电流信号。     

长寿命电极水位检测电路

在水位探测电路中，最简捷的当属电极式水位计，即用导体作为电极检测水位的高低。但其最大的弊病就是电极易受电蚀而失效。电极浸在水中，当有电流流过电极时。即或电流很小，也会对电极产生电解作用。实验证明，无论是用何种导电材料作电极，包括铜、不锈钢、碳棒等，都会使正电极受到电蚀。电蚀的程度与通电时间及电流大小     

三相电弧冶炼电炉自动化控制系统

从硬件和软件两个方面对三相电弧冶炼电炉自动化控制系统进行了详细的设计。硬件电路由电极初始化，电流取样，模数转换及执行部件电路四部分构成。软件是建立在WINDOWS基础上的由汇编语言编写的控制程序。     

水力空化水处理设备的控制系统设计

为了完成对水力空化水处理设备的自动控制,结合水力空化水处理技术工艺,应用PLC控制器和触摸屏技术,开发并设计一套水力空化水处理设备的控制系统。采用触摸屏作为人机界面,可实现pH、ORP、电导率、DO等水质参数实时检测、设定和修改等功能,并能方便直观地对水力空化水处理设备的工作过程进行监控。经过实际运行和调试,基于PLC和触摸屏的水力空化水处理设备的控制系统稳定性好、可靠性高、易于维护,提高了水力空化水处理设备的效率和自动化水平。     

远离平衡及无供轭反应时气体传感器的电势响应—电势型臭氧传感器初探

对固体聚合物电解质（ＳＰＥ）气体扩散电极在臭氧中电势上升暂态的分析表明，在无共轭反应的情况下，电势的上升是臭氧还原以双电导层的过程。这一过程中电极远离平稳电势，不服从Ｎｅｒｎｓｔ公式。电势的上升最终将折氧反应截止于一对臭氧浓度不很灵敏的电势。在析氧之前，由于无明确共轭反应，电极电势不能有效地指示臭氧的浓度。接在工作电极和参比电极之间的负载电阻可使臭氧还原在工作电极上积累的正电荷得以释放，起相当于共     

基于柔性电极的便携式心电监测系统研究

针对普通干电极和医用湿电极应用于心电监测系统时存在的问题,制备了 一种聚二甲基硅氧烷(polydimethylsiloxane,PDMS)基底上阵列金字塔结构的柔性电极.该电极通过阵列金字塔结构加大电极表面积,减小电极阻抗,并对心电信号处理电路、基于安卓端的APP等部分进行了设计,制作了便携式心电监测系统.实验结果表明...     

PLC在水厂水处理过程中的应用

本文以某水厂净水间水处理系统为例，简述了在水处理过程中运用PLC应用程序软件程替代硬件电路，来实现过程控制。     

基于集成参比电极的多参数水质监测微传感器阵列研制

研究了一种基于MEMS工艺制备的集成微电极型传感器,并用电化学修饰方法将Ag/AgCl参比电极集成在传感器上,用于水体中温度、电导率和氧化还原电位的测定.Pt温度传感器的电阻与温度的线性关系良好,满足温度测量精度的需求;比较法确定电导率传感器的电极常数为2.723,可以对一般水体的电导率进行测定;氧化还原电位传感器的标...     

基于模糊神经网络的臭氧净水机智能控制研究

提出了一种基于模糊神经网络的臭氧杀菌净水机的控制方法,首先,分析了影响臭氧净水机臭氧含量的因素,再根据实验数据,利用模糊神经网络建模,得到了外界水温水压与臭氧管上的对应高压脉冲频率的非线性关系,并在此基础上设计出一种以数字信号处理器为控制核心的适应环境变化的智能臭氧净水机,实验表明,这种新型臭氧净水机能够保持稳定的臭氧浓度,有效杀菌.     

Robust on-line control of hexavalent chromium reduction process using a Kalman filter

In waste water where toxic hexavalent chromium ions are present, it is essential that the hexavalent chromium ions are reduced to the less harmful trivalent chromium ions by dosing with reducing agent such as ferrous sulphate. The problem posed in controlling such a reduction process is that chromium ions cannot be easily measured on-line. In such a process, oxidation-reduction potential (ORP) is widely used. The ORP value, apart from being dependent on the concentration of chromium ions, is also dependent on other redox processes due the presence of other ion species, concentration of ions, temperature, etc. For this reason, the reduction process cannot be effectively controlled using conventional set-point control. The profiles of the ORP during the reduction process shows certain characteristic features which can be used as an indication of the completion of the process. In this paper we have successfully demonstrated a robust switching algorithm using a Kalman filter to control the dosing pump for this reduction process.     

砷盐净化除钴镍过程氧化还原电位的优化设定

在湿法炼锌净化除钴镍过程中,锌粉的加入量由现场的氧化还原电位(ORP)测量仪控制。针对净化除钴镍过程中ORP与钴离子浓度难以建立精确数学模型,提出了一种基于案例推理(Case-Based Reasoning,CBR)技术的除钴镍过程氧化还原电位的优化设定方法。为了克服案例推理最近邻检索(KNN)算法易受单个特征属性干扰及近邻个数选取具有很大的主观性因素影响,采用遗传算法优化特征属性权重和近邻数,提高案例的检索精度。基于案例推理的ORP优化设定方法在工况条件发生变化时,能够自动调整ORP设定值,实时调整锌粉添加量,实现了锌粉的优化添加,降低了锌粉的消耗。     

控制电位型水中臭氧电化学传感器的试验研究

阐述了控制电位型水中臭氧电化学传感器的结构及其原理,通过对循环伏安曲线、极化曲线和不同电位时的电流响应对比曲线的综合分析,得出控制电位为0.50 V时传感器电流响应线性度好、灵敏度高。此外,设计并应用了电位控制和测量电路,实现了对传感器的电位控制以及输出信号的处理。     

Boundary layer development and meteorological parameters impact on the ground level ozone concentration over an urban area in a mountain valley (Sofia,Bulgaria)

The ecological problems caused by the increasing ozone concentration are not easily solved because ozone is not directly emitted by certain sources Its concentration depends on numerous dynamical and chemical processes. Stratosphere–troposphere exchange and subsequent ozone penetration into the boundary layer determine the contribution of so-called ‘natural’ ozone to ozone pollution near the ground. However, the main contribution to the concentration of this pollution is that of the anthropogenic ozone, which is generated as a result of complex photochemical reactions. The purpose of this research is the ground level ozone concentration behaviour to be studied during the stable boundary layer (SBL) and the residual layer (RL) destruction and the convective boundary layer (CBL) formation, so the influence of the temperature, the relative humidity and the height of the mixing layer (ML) as well as that of the ML formation in different areas of Sofia (42° 39′ N, 23° 23′ E, 591 m above sea level), Bulgaria, have to be determined. The ground level ozone concentration in the area of the Institute of Electronics changes synchronously with the development of the ML. The maximum values of the ground level ozone concentration are reached when the height of the ML reached its maximum and afterwards. The maximum growth of the ground level ozone concentration is around 11:00–12:30 h LST when a fast growth of the ML begins and the complete destruction of the RL is observed, that is, the two processes of ML growth and entrainment of aerosol and ozone from the higher layers of the atmospheric boundary layer are observed. The values of the ground level ozone concentration during the summer months are higher than those during the fall.     

Contour diagram fuzzy model for maximum surface ozone prediction

A contour diagram approach is presented for the identification of surface ozone concentration feature based on a set of rules by considering the meteorological variables such as the solar radiation, wind speed, temperature, humidity and rainfall. A fuzzy rule system approach is used because of the imprecise, insufficient, ambiguous and uncertain data available. The contour diagrams help to identify qualitative ozone concentration variability rules which are more general than conventional statistical or time series analysis. In the methodology, ozone concentration contours are based on a fixed variable as ozone precursor, namely, NO_x and as the third variable one of the meteorological factors. Such contour diagrams for ozone concentration variation are prepared for six months. It is possible to identify the maximum ozone concentration episodes from these diagrams and then to set up the valid rules in the form of IF-THEN logical statements. These rules are obtained from available daily ozone, NO_x and meteorological data as a first approximate reasoning step. In this manner, without mathematical formulations, expert maximum ozone concentration systems are identified. The application of the contour diagram approach is performed for daily ozone concentration measurements on European side of Istanbul city. It is concluded that through approximate reasoning with fuzzy rules, the maximum ozone concentration episodes can be identified and predicted without any mathematical expression.     

PLC在污水处理厂控制系统中的应用

主要介绍了污水处理厂控制系统的组成以及各部分的功能,重点介绍了采用溶解氧仪和氧化还原电位计结合起来的曝气控制模型。     

Regressor selection for ozone prediction

Being able to predict high concentrations of tropospheric ozone is important because of its negative impact on human health. In this paper eight regressor-selection methods are utilised in a case study for ozone prediction in the city of Nova Gorica, Slovenia. The comparison of the selected methods proved to be useful for building models that successfully predict the ozone concentrations for the treated case. Different regressors are selected for different models, with different methods based on the validation procedure’s cost functions. Namely, for the model to predict the maximum daily ozone concentration, ten regressors are selected; for the average concentration of ozone between 8.00 and 20.00 h, fifteen regressors are selected; and for the average daily concentration, ten regressors are selected. The result of the study is a regressor selection that is specific for a particular geographical location. Moreover, the study reveals that regressor selection, as well as the obtained models, differ depending on the kind of averaging interval of the ozone concentration.     

基于多传感器数据融合技术的臭氧监测系统设计

针对臭氧在进行保鲜和消毒时的特点和要求,设计了一种基于多传感器数据融合技术的监测系统,用来严格监测臭氧浓度。系统采用自主设计且拥有专利的臭氧传感器进行数据采集,并通过搭建无线传感器网络实现对臭氧浓度的实时监测。为了提高数据的准确度,首先要剔除可疑数据,然后选择适当的算法对数据进行数据融合。仿真结果表明:数据融合后所得到的融合值更加平稳,可靠性高,通过选择适合的融合算法可以提高臭氧浓度采集的精度。