适合产业界需求的位置传感器

位置传感器的历史悠久，伴随着产业机械的自动化而不断进步。早期的自动化机械只使用机械式的行程开关、微动开关等传感器，但随电子技术的进步，现在无触点式的传感器占主流。代表性的传感器有接近开关、光电开关、超声波开关。这些位置传感器起初种类较少，因而可使用的行业也受到限制、但是，随着各个领域的自动化进展，逐步开发了适合市场各种用途的传感器。本文就最近开发的位置传感器所适合使用的产业界和这些产业界的需求动向以及应用上的注意事项等作一介绍。各产业和传感器的需求动向在此以位置传感器使用较多的汽车、立体停车场、…     

一种机械故障监测的信息融合

在叶片振动故障监测过程中，单传感器的间断相位法只能测得叶片振幅值信息，本文应用两个传感器的信息融合技术，通过多源信息的综合、分析和推理，得出了叶片振动频率信息，提高了传感器系统的有效性，消除了单个传感器的局限性。     

声发射检测中的压电换能器

在声发射检测中，传感器是获取信息的关键部件之一。目前绝大部分声发射传感器都是压电换能器。就采用压电原理的声发射传感器的发展及其校准问题作概述，对声发射传感器中的特殊问题孔径效应及其对传感器设计、性能和校准的影响进行讨论。     

基于遗传算法的传感器创新设计的研究

遗传算法具有较强的全局随机搜索能力，在编码、选择、交叉、变异等方面对基本遗传算法进行改进，提高其效率和性能，并利用改进的遗传算法对传感器效应进行学习，同时确定效应模型中的输入、输出参数的最佳组合。利用所得的效应模型为传感器的研发提供原理支持，实现传感器的创新设计。同时分别利用自适应遗传算法对传感器设计的遗传算子进行计算，利用messy GA对个体进行遗传操作。所开发的传感器创新设计软件运行良好，但仍需不断的完善。     

基于虚拟仪器和传感器阵列技术的综合无损检测系统

介绍了一种基于虚拟仪器和传感器阵列技术，利用计算机系统的强大资源和LabVIEW软件，集超声、涡流和磁记忆三种探伤方法于一体的综合式智能无损检测系统，超声和涡流传感器采用阵列探头方式，磁记忆传感器采用多通道形式，且除传感器外，所有硬件都装在一部便携式计算机内。因而具有功能强大、技术超前、扩展性好、携带方便等特点，非常适合于在探伤工作机动性和高效性要求高的场合以及大型复杂设备的检测。     

压铸机测控系统的设计与实现

介绍了基于Windows图形界面的压铸机测控系统的设计思想和实现方法。介绍了对压力传感器、位移传感器、变形传感器的选用，在手动系统中引入了延时卸荷，同时设置了动作设置功能。     

高速旋转电弧传感器

介绍了一种高速旋转电弧传感器，与现有的同类传感器相比，具有结构紧凑，灵敏高度的特点，并叙述了电弧传感器的信号处理技术的控制系统，用此技术构成的电弧传感器跟踪控制系统可直接用在生产上。     

声发射研究用的非接触式传感器

与常用压电声发射能器不同，声发射研究中使用的非接触式宽带传感器主要有两种，即电容传感器和光学探测器，为了削弱孔径效应，空气间隙的电容传感器采用了不同的结构。光学探测器则是建立在激光干涉的基础上，利用偏振干涉方法研制的光学探测器是传感器的一种优化设计，而光纤传感器在实现声发射技术的现场应用中有许多潜在的优点。     

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 文章着重论述了传感器在现代测试系统中的重要地位，以目前最常用的压电式传感器为例，探讨了正确选择传感器的几大要素，并通过试验曲线论证了传感器特性对测试结果的影响。     

用双桥法减小压阻型传感器的温度漂移

论述了温度对压力传感器输出灵敏度的影响，为了减小传感器输出的温度漂移，利用双惠斯登电桥方法进行补偿，在300～373K的温度范围内对传感器进行了测试。结果表明，采用双桥法补偿后，传感器输出的温度漂移可以降低70％以上。     

Fracture mechanics tests for measuring the adhesion of magnetron-sputtered TiN coatings

Experiments for determining the adhesion strength between TiN coatings and high speed steel substrates have been performed by using the three-point bending test and a modified shear test. Sample preparation is easier for the modified shear test; however, the interpretation of results is more complicated. The three-point bending test yields fracture mechanics data such as the interface fracture energy G_c and the fracture toughness K_c. The most critical problem is to prepare a sample with a notch which initiates crack propagation at the film-substrate interface. Various sublayers with weak adhesion, such as carbon, oxide and metals, have been tested as a notch, as well as thin mechanical slits. The results obtained so far demonstrate that the adhesion strength depends on the substrate cleaning treatment and on the impurity gas content in the receiver. Typical values of the fracture toughness K_c for substrates that have not been sputter cleaned are in the range 1–3 MN m^-3/2. Advantages and disadvantages of the various methods used are analysed and critically discussed with respect to sample preparation, reproducibility and data evaluation.     

混流式转轮焊接残余应力测试新装置与新方法

混流式转轮叶片出水边焊接接头区域存在的较高残余应力是导致转轮疲劳开裂的重要原因,混流式转轮焊后及热处理后的焊接残余应力测试已经成为转轮制造过程中的必要工艺,其测试精度及效率对转轮制造质量及效率有重要影响.根据转轮的结构特点研发了新型残余应力测试装置,并根据转轮疲劳开裂的特点确定了针对混流式转轮焊接残余应力测试的新方法,实际应用试验结果表明测试所得结果能够真实反映热处理前后转轮易开裂区域的残余应力分布情况.新型测试设备及方法完全适用于混流式转轮的残余应力测试,而且具有非常高的测试精度及效率.     

金属材料屈服强度测量中几种异常情形分析

探讨了金属材料屈服强度测量中几种异常情形，诸如试样滑动、测 Rp0.2时引伸计失效、位移法测 Rp0.2时平行长度选取不当等情况。描述了异常情形下试验曲线的特征，分析了产生原因和对试验结果的影响，提出了预防措施。在日常工作中不要盲信试验机自动得出的测量结果，每次试验后应核查试验曲线是否正常，核查屈服点在试验曲线上的选点是否正常。     

切割丝拉伸试验的测量系统分析

介绍破坏性试验的测量系统分析方法,采用交叉分析方法进行切割丝拉伸试验的重复性与再现性的测量系统分析。去除内控样引起的偏差后,切割丝的偏倚性、线性、稳定性及重复性与再现性的拉伸数据分析显示,该测量系统满足测量要求。     

‘PERMIT’ ion migration test for measuring the chloride ion transport of concrete on site

The ingress of chlorides into concrete is predominantly by the mechanism of diffusion and the resistance of concrete to the transport of chlorides is generally represented by its coefficient of diffusion. The determination of this coefficient normally requires long test duration (many months). Therefore, rapid test methods based on the electrical migration of ions have widely been used. The current procedure of chloride ion migration tests involves placing a concrete disc between an ion source solution and a neutral solution and accelerating the transport of ions from the source solution to the neutral solution by the application of a potential difference across the concrete disc. This means that, in order to determine the chloride transport resistance of concrete cover, cores should be extracted from the structure and tested in laboratories. In an attempt to facilitate testing of the concrete cover on site, an in situ ion migration test (hereafter referred to as PERMIT ion migration test for the unique identification of the new test) was developed.The PERMIT ion migration test was validated in the lab by carrying out a comparative investigation and correlating the results with the migration coefficient from the one-dimensional chloride migration test, the effective diffusion coefficient from the normal diffusion test and the apparent diffusion coefficient determined from chloride profiles. A range of concrete mixes made with ordinary Portland cement was used for this purpose. In addition, the effects of preferential flow of ions close to the concrete surface and the proximity of reinforcement within the test area on the in situ migration coefficients were investigated. It was observed that the in situ migration index, found in one working day, correlated well with the chloride diffusion coefficients from other tests. The quality of the surface layer of the cover concrete and the location of the reinforcement within the test area were found to affect the flow of ions through the concrete during the test. Based on the data, a procedure to carry out the PERMIT ion migration test was standardised.     

ICP-AES光谱仪测定Al-Si合金中元素含量

通过对Al-Si合金中各元素的ICP-AES光谱仪分析方法及影响因素进行研究,优化了仪器的工作条件,选择适当分析线,并进行了精密度及加标回收率实验,制定了相应的分析规程,提高分析数据的准确度,提高了分析速度,节省大量试剂。     

基于NI测控系统的风电主轴轴承试验机

从试验机的组成结构、电控系统、测控系统等三个主要方面,详细介绍了我们自行研制的风电主轴轴承试验机.在NI测控系统中,从测控原理、软件简介、软件设计等三个方面介绍了基于LabVIEW的测控系统.     

Evaluation of techniques for measuring corrosion activity of carbon steel welds

Abstract

Three test methods, namely immersion tests, galvanostatic anodic dissolution tests and the scanning vibrating probe technique, have been evaluated as candidate methods for ascertaining the susceptibility of welds in carbon steels to preferential corrosion. The use of hardness measurements by profiling and mapping was also evaluated. Three welds were tested for which the production had been controlled to produce different types of corrosion behaviour. In addition, a weld that had failed 'in service' was used to validate the findings of this assessment. In the immersion tests, lasting 9 months, the three controlled weld specimens ex posed to ASTM D1141 sea water behaved as expected, in terms of which region of the weld was most susceptible to corrosion. The results of the rapid galvanostatic anodic dissolution tests compared well with those of the immersion tests, with the same regions of the controlled welds showing susceptibility to corrosion. The galvanostatic anodic dissolution test on the failed weld produced corrosion in the regions that had been susceptible to corrosion in service. However, at very high current densities the differential corrosion loss between different regions of the weld was not maintained and careful control of this parameter is therefore necessary in testing. The scanning vibrating probe technique successfully identified the areas susceptible to preferential corrosion in both the controlled weld specimens and the in service failure. The electrolyte used was ASTM D1141 sea water diluted 10 : 1 with distilled water. However, these trends were not apparent when tests were conducted in distilled water owing to the lower solution conductivity. Hardness mapping produced a two-dimensional visual representation of the specimen hardness. This was very effective in locating small regions of high hardness, in contrast to conventional hardness profiling, and would be effective in locating hot spots for hydrogen embrittlement. However, no correlation between hardness and corrosion susceptibility was observed in the three weld specimens that were examined. The galvanic anodic dissolution test is recommended as a rapid and reliable test to determine the relative corrosion susceptibility of carbon steel welds. The scanning vibrating probe technique can also be effective but at considerably greater expense.     

双引伸计法同轴度测量仪的不确定度分析

分析了双引伸计式同轴度测试仪的数学模型，建立了不确定度的评定方法，在高温蠕变持久试验机上进行了同轴度校准试验，参照JJF 1059.1-2012《测量不确定度评定与表示》计量技术规范，分析了不确定度评定中各个分量的来源并进行了综合评定，完善了同轴度校准的实际操作方法，提高了数据的准确性。     

Ultrasonic technique for measuring porosity of plasma-sprayed alumina coatings

Porosity is an important factor in plasma-sprayed coatings, especially ceramic coatings. Excessive poros-ity can adversely affect the performance of the coated component in various ways. An ultrasonic nonde-structive measurement technique has been developed to measure porosity in plasma-sprayed alumina coatings. The technique is generic and can be extended to other ceramic coating systems. To test the tech-nique, freestanding alumina coatings with varying levels of porosity were fabricated via plasma spray. Samples with varying porosity, obtained through innovative fabrication techniques, were used to gener-ate a calibration curve. The ultrasonic velocity in the low-frequency range was found to be dependent on the density of freestanding coatings (measured via Archimedian techniques). This dependence is the basis of the development of a technique to measure the density of coatings.