船用计程仪传感器现场故障测量模型及应用

提出了一种船用计程仪传感器检测的新方法.依据电化学原理建立起传感器导电机理的数学模型,利用双脉冲激励源测量电路测量传感器、电极、海水综合系统的电导值,进而定量判断传感器的好坏.可在海上即时监测传感器的工作情况,克服了传统方法必须进坞上排后才能进行检测这一不足,可节省大量的人力,物力和时间.实验结果表明该方案达到了预期设计的要求.     

一种水中兵器集成试验测试系统的设计与研究

为了适应水中兵器多科目、综合性试验测试的需求,研究并设计了一种水中兵器集成试验测试系统--武器试验船多测量源导航和目标跟踪系统.基于统一的PC-LAN基础测试平台,该系统可有效地协调平台上各种测控设备共同完成试验测试,并充利用融合多测量源的信息,具有导航参数测量、多目标跟踪、测控信息综合处理和试验指挥显示等功能,系统具有较好的可靠性和通用性.介绍了该系统的原理和构成,讨论了数据记录管理中件和导构系统集成等关键技术.     

基于电压脉冲激励的液体电导测量新方法

本文介绍了一种基于电压脉冲激励技术的新型液体电导测量的电路.它不仅能够消除介质的极化现象,还能避免传统交流激励模式下所必须的放大、滤波、信号调理及A/D转换环节,从而简化了电路结构,同时提高了测量速度及精度.适用于测量速度要求高、测量信号微弱的条件下使用.此电路的特点是激励频率与采样频率相同,直接进行数字量测量.实验测试的结果表明,在等效电阻从0.1～3 kΩ变化时,电路能够分辨出的电阻变化值小于0.05%.     

激光测距仪器维修训练系统的激励电压源设计

激光测距仪器维修训练系统可满足多种型号测距仪器的测试需求,而激励电源是该系统的关键部件。对基于USB总线的程控激励电压源进行了设计,可调电压源主要由ATmega16单片机与4通道数字电位器AD8403等器件构成,USB通信电路由ATmega16与PDIUSBD12构成,并且在Windows XP系统下开发了相应的WDM驱动程序。测试结果表明该激励电压源能够满足激光测距维修训练系统要求。     

调制激光器激励法的热电偶时间常数测试

提出一种利用大功率高频调制CO2激光作为激励源,对表面温度传感器进行时间常数测试的新方法。建立了时间常数测试系统,对温度范围不同、时间常数各异的热电偶进行了时间常数测试,给出了测试曲线。实验证明该系统可以测试亚毫秒至秒量级表面温度传感器的时间常数,其激励源所提供的温度阶跃可覆盖常温至高温范围。     

高精度电阻在线测量方法研究

为了解决电子产品检验中的高精度电阻在线测量,提出了基于差分隔离法的电阻在线测量新方法,给出了新颖的程控激励源和程控差分放大器电路.该方法从根本上消除了以往隔离技术激励信号源内阻不为零和旁路电阻对测量精度的影响,测量精度和系统量程均提高了约一个数量级.     

基于计算机一体化无源互调测试系统的研究

无源器件互调失真对通信系统的接收有很大的影响,一般来说无源互调电平随其阶数的增加而降低,接收通带中的最低波段受到PIM干扰的影响最大,严重时甚至会导致通信系统的失效,而且对其测量比较困难.针对目前的无源互调测试系统大多是分布式,测试极为不便的现状,本文研制出了一种一体化的无源互调测试系统.该测试系统集成了计算机控制系统,使用自主研发的软件系统.与标准件的实验测试结果对比显示,该分析仪具有很高的测试精度.同时,采用Gage R&R分析法对不同被测器件由不同操作人员进行多次测试,测试结果表明,该测试系统具有很好的可靠性与可重复性.     

低电压电泳芯片非接触电导检测电路设计(英文)

根据低电压集成电泳芯片柱端非接触高频电导器的结构和非接触高频电导检测的基本原理,设计了非接触电导检测电路.该电路包括AC激励信号发生器、I-V转换器、乘法运算器、低通滤波器和差分放大器.运用较少的元器件和较简单的电路形式实现了检测功能,解决了低电压电泳芯片微弱的非接触电导信号检测困难的问题.通过调节电路参数分别得到了频率为450 kHz和1 MHz,幅值为10 V的正弦信号.在此激励信号下,在集成低电压电泳芯片上对一系列不同浓度的K+溶液进行了非接触电导响应信号的测试.实验结果表明,电路能分辨的离子浓度的下限为10-9;离子浓度为10-9～10-5时,电路响应具有很高的线性度和分辨率.该电路亦可用于其它微弱电导信号检测领域.     

基于TSE G144声表面波传感器的温度测量系统设计

文中分析了声表面波谐振器的工作原理,建立了基于TSE G144传感器的谐振型无源无线温度测量系统。该系统可分为硬件系统:包括传感器、信号源、混频器、放大器、收发开关、单片机等模块;软件系统:包括激励发送、回波接收、谐振分析和频率温度计算等。最后,对软硬件系统进行了温度实验测试,不仅测量精度达到了±0.8℃的优良水平,灵敏度也达到了9.2 kHz的高度,显示了测量系统良好的应用和发展前景。     

毛细管电泳芯片非接触电导检测系统设计

针对毛细管电泳芯片检测系统的微型化,基于ARM11微处理器和嵌入式Linux操作系统,通过自制激励源与信号检测电路,编写驱动程序和上位机软件,设计了一款体积较小的用于毛细管电泳芯片检测的非接触电导检测系统。激励源交流电压频率在10~400 k Hz之间连续可调,电压幅值在0~10 V变化。通过使用电极宽度为1 000μm、电极间距为800μm的电泳芯片对系统进行测试,在频率100 k Hz、10 Vp-p的激励信号下,对浓度为10-3mol/L的氯化钾溶液进行检测,可得到相对峰值大于200 m V的检测信号。     

土壤电导率测量系统开发

介绍一种基于“电流一电压四端法”的土壤电导率测量系统的开发。该测量系统由传感器单元、数据采集器USB2808和计算机软件等部分组成。传感器单元包括4个电极,2个外侧电极用来向土壤中输入交流恒流激励信号,2个内侧电极用来检测与土壤电导率相关的电压降。数据采集器USB2808用来将传感器测得的模拟电压信号转换为数字电压信号。计算机软件使用VC＋＋来开发人机交互界面,实现了输入恒流值、内侧电极电压降、土壤电导率等值的显示,并可将这些值保存到数据库中。试验结果表明该测量系统可以有效输出土壤电导率的值。     

分布式无线土壤电导率测量装置的设计

采用电流电压四端法设计一种多点无线传输的土壤电导率测量装置.硬件部分采用TDR-4传感器的四针微型探头可减小对溶质运移的扰动,且可高密度分布在土壤中,系统连接多路电导率探头和8位高精度数据转换器能够实现多通道土壤电导率测量,并通过无线模块实现系统规模的扩展,采用主从式结构测量显示平台能够完成数据采集、显示与存储功能,有效解决了多点土壤电导率实时监测的一致性问题.试验结果表明:系统具有良好的稳定性,土壤电导率与含盐量呈线性变化.     

非接触式地表水电导率检测系统

将电容耦合非接触电导检测技术应用于地表水电导率检测,研制了非接触式地表水电导率测量传感器,建立了一种新型非接触式检测系统.利用有限元仿真的方法建立了传感器的仿真模型,对传感器结构参数的优化进行了研究,并分析了该系统的抗杂质干扰能力.系统测试结果表明,将该检测系统应用于地表水电导率检测是可行的.该系统具有传感器结构简单、电极非接触和抗杂质干扰能力强等特点,可以满足地表水电导率野外长期在线实时检测的要求.     

Eddy Current Testing of Metallic Materials Using Projection Methods

Using the example of nonmagnetic metallic materials, the projection methods of multidimensional analysis of multifrequency eddy-current testing measurement data presented for processing are considered. Based on the principal components method, the effects of electrical conductivity and sensor–material-surface gap on the results of testing have been separated. Using regression on principal components, the numerical values of the electrical conductivity and gap for manganese, copper, bronze, aluminum, and an aluminum alloy have been obtained. The results make it possible to extend the possibilities of nondestructive eddy-current evaluation of materials.     

声表面波谐振器型无源无线温度传感器

介绍了一种新型的单端口声表面波谐振器构成的无源无线温度传感器。分析了间歇正弦信号无线激励的单端口声表面波谐振器的响应特性。该响应为幅度衰减的振荡信号，振荡的中心频率为声表面波器件固有频率。设计并构造了高效、快速、较远距离自动无线遥测温度的实验系统，实验系统验证了测量原理的正确性。     

Miniature conductivity wire-mesh sensor for gas-liquid two-phase flow measurement

A miniature conductivity wire-mesh sensor for gas-liquid two-phase flow measurement in small channels is presented. The sensor design is similar to the conventional wire-mesh sensor for larger flow cross sections with wire electrodes stretched across the flow channel in two adjacent planes and with perpendicular wire orientation between planes. Conductivity measurement is performed by special electronics which consecutively applies bipolar voltage pulse excitation to the sender wires and measures electrical current flow in the wire crossings at the receiver wires. The new design is based on printed circuit board technology. A prototypical sensor made of 2×16 stainless steel wires each of 50 μm diameter was manufactured and applied to two-phase flow measurement inside the mixing chamber of an effervescent atomizer. Accuracy of the sensor was studied for static liquid distributions using microphotography and for dynamic two-phase flow by comparison of wire-mesh sensor data with radial gas fraction profiles obtained from X-ray microtomography measurements.     

双孔平行梁式称重传感器非线性校正研究

针对双孔平行梁式称重传感器检测过程中受温度和电路干扰等因素引起的非线性问题,提出了基于SVM（support vector machine：支持向量机）理论的非线性补偿方法。分析了存在于传感器测量值中的非线性特性,建立了以检测电压参数为输出、以重量参数为输入的SVM逆模型。通过SVM逆模型与自适应模糊推理系统（ANFIS）仿真对比,验证了SVM逆模型针对双孔平行梁称重传感器线性校正的有效性。结论表明,测试样本的模型预测平均误差为0.027g,达到了较好的线性度,实现了双孔平行梁式称重传感器非线性补偿的目的。     

霍尔器件参数测试系统

提出了一种基于微控制器的霍尔器件参数测试系统设计方案.描述了总体设计方案,并详细介绍了硬件部分的可调电压源和数据采集部分.给出了系统软件设计思想及部分参数的测试结果.该霍尔器件参数测试系统可以快速准确地测量霍尔器件的各项电参数和磁参数,并且具有测试和筛选功能,操作界面友好,使用方便.     

Robust computational framework for wire-mesh sensor potential field calculations

With the development of the next generation of nuclear reactor safety system codes fast underway, increased importance has been placed on enhancing physical closure correlations and amassing representative benchmark-quality experimental data for validation purposes. Wire-mesh sensors, a reputable experimental measurement technique with sufficient spatial and temporal resolution to serve such goals, and related data reconstruction algorithms have been the subject of renewed interest as researchers attempt to characterize their measurement uncertainty. To assist in such investigations, the present work establishes a comprehensive numerical framework with which to quantify the electric potential field around wire-mesh sensors. Using the finite-volume foundations of OpenFOAM, a numerical solution algorithm is developed to predict the transmitted electric current between transmitter and receiver electrodes for both homogeneous and heterogeneous electrical conductivity fields. A detailed verification against seminal numerical calculations and robust validation procedure is included to ensure the accuracy of the proposed methodology. Parametric studies of spherical bubble diameter, lateral crossing position, and spheroidal shape influence are conducted to provide preliminary insights into wire-mesh sensor operation and the suitability of various calibration approaches. Observed trends in the transmitted currents reveal overshoots relative to calibration conditions, which are fundamentally linked to the maldistributed electric potential field in heterogeneous bubbly flows. The present investigation offers a vital first step towards a comprehensive multi-physics model of multiphase flow around a wire-mesh sensor.     

An equivalent electrical circuit design for pipeline corrosion monitoring based on piezoelectric elements

Underground pipelines are important infrastructure for transporting energy resources, particularly water and oil. Due to the high risk of damage and possible consequences, close monitoring of pipelines is a serious challenge for researchers and decision makers. Piezoelectric sensors/actuators are being used to monitor the physical characteristics of pipelines, including corrosion and crack. Piezoelectric ceramics as transmitters and/or receivers are connected to data concentrators in order to monitor the defects in pipelines. The performance and accuracy of this system highly depends on the accurate interpretation of the received electrical signals due to changing mechanical fields. However, due to the existence of two different fields, namely, electrical and mechanical, in this problem, simulation and interpretation of the damages occurring in pipelines is a consistent challenge. This paper proposes an equivalent electrical circuit model for a complete monitoring system which contains piezoelectric ceramics and a pipeline equivalent electrical circuit with corrosion defects and cracks through the pipeline. The pipeline is integrated with PZT sensor and actuator, in which PZT actuator generates waves along the thickness of the pipeline and its response is received by a PZT sensor. The proposed model approximates the electrical signal achieved by the PZT sensor to a complete health monitoring system. As the sensing signals in the present model are in one single field (i.e. electrical instead of mechanical and electrical), analysis and signal processing are more efficient, and the results are better understood. Numerical examples and, where applicable, simple tests have been presented to show the functionality and performance of the system.