热电偶测温的若干问题

本文计论了执电偶用于温度测量中的若干问题,并着重阐述了冷端补偿问题,给出了实用电路,具有较强的应用性和参考价.     

热电偶测温的若干问题

本文讨论了热电偶用于温度测量中的若干问题,并着重阐述了冷端补偿问题,给出了实用电路,具有较强的应用性和参考价值。     

热电偶冷端补偿的两种方法

文章详细讨论了热电偶冷端处理的两种方法，这两种方法对高精度测温和现代温控仪的设计具有实用的参考价值.     

热电偶冷端补偿器LT1025及其应用

简要介绍了凌特公司生产的微功耗热电偶冷端补偿芯片LT1025的原理及其应用。在温度测量时．该芯片可用于对各种热电偶的冷端进行温度补偿，且在较广泛的温度范围内具有较高的补偿精度。     

热电偶冷端补偿电路AC1226及其应用

简要介绍美国ＡＤ公司近年来生产的集成电路芯片ＡＣ１２２６的结构及其原理。该芯片可用于在温度测量时，对各种电偶的冷端进行温度补偿，且具有较高的补偿精度；它还可用于环境温度监测。     

热电偶测温系统设计

用热电偶测量温度是航空温度测量中应用最广泛的一种方式,常用来测量高温气流及高速气流。提出了一种可以应用于管道内流体测量的热电偶测温系统的设计方法:以热电偶作为感温元件,配合变换器实现准确可靠的温度测量,输出的电压信号与对应温度成线性关系。通过设计实例及试验,验证了系统的精度性能,实现了预期的设计目标。     

基于热电偶的测温仪表冷端补偿方法

热电偶是测温仪表中常用的温度传感器之一。在测温过程中,难以保证热电偶冷端恒温,所以对测量结果必须进行冷端补偿。文中以热电偶工作原理为基础,由PT1000测量冷端温度,通过A/D转换后由MCU传给上位机,将电阻值通过软件换算成电压值加到热电偶的电压上,再通过补偿块消除冷端温度变化带来的影响,从而进行补偿。试验表明,该方法不仅测量精度高,且工作稳定。     

燃烧合成高压釜测温测压虚拟仪器

温度和压力是化学反应过程中两个重要的参数。在高压釜的测温测压系统中,本文给出了实现热电偶冷端补偿电路和压力采集电路的解决方案,以虚拟仪器LabVIEW6．1为软件平台,实现了多路温度和压力测量集成,开发出了高精度、高效率、实时可视的测温测压程序。     

Reliability of Thermoelectric Couple Networks Based Upon Couple Catastrophic Failures

A limited reliability mathematical model for series-parallel configurations of semiconductor couples used in radioisotopic thermoelectric generators (RTGs) is constructed. The model represents catastrophic failure reliability, which is only one important part of the total effective reliability mathematical model. It is deliberately narrow; two other major components of couple reliability, drift and load mismatch, are not discussed. The synthesis of the model, its use, and limitations are described. Probability relationships between the availability of a minimum specified power level and the assurance of electrical continuity form the framework of the model. The configuration under study is similar to internal arrangements of other power devices such as solar cells and battery cells. Here, open circuit is considered the only failure mode, viz., the probability of short circuit is negligible. The model can be applied to other power devices. Its algorithm form is suitable for adaption to a computer code.     

基于单口S参数的超声换能器有载匹配研究

介绍了基于单口S参数理论进行超声换能器匹配的原理,并利用网络分析仪测量超声骨科换能器在空载和各种组织负载下的反射系数.结果表明,负载对换能器的匹配有很大影响.为提高切割效率,匹配电路中的变压器的变比应随负载的变化而进行自动切换.实验研究表明,采用相应的匹配电路后,空载反射系数绝对值增加了4倍,松质骨为负载时的反射系数绝对值增加了30倍以上,增加了负载输出功率.     

Performance Results of a High-Power-Density Thermoelectric Generator: Beyond the Couple

This paper describes the development of a high-power-density thermoelectric generator (TEG) with a power output of greater than 100 W. Previous papers have described the development of the generator made of high-power-density TE couples. In this discussion, initial thermal cycling results for the TE couples are described. The building blocks are then scaled and integrated into a complete TEG. The design, build, and test of the TEG are discussed. The high-power-density design produces power at greater than 250 W/L and 80 W/kg. Test results are shown for varying flow rates, temperatures, and electrical loads.     

Computational Study on Temperature Control Systems for Thermoelectric Refrigerators

Thermoelectric refrigeration has the outstanding advantage of allowing accurate temperature control. However, on the market there are thermoelectric refrigerators which include on/off temperature control systems, because of their simplicity and low cost. The major problem with this system is that, when the thermoelectric modules are switched off, the heat stored in the heat exchanger at the hot end of the modules goes back into the refrigerator, forming a thermal bridge. In this work, we use a computational model, presented and validated in previous papers, to study alternative control systems. A new system is introduced based on idling voltages; that is, once the temperature of the refrigerator reaches the lower limit, the thermoelectric modules are not switched off but supplied with minimum voltage. Computational results prove that this system reduces the electric power consumption of the refrigerator by at least 40% with respect to that obtained with on/off control systems, and the coefficient of performance increases close to the maximum provided by any other control system.     

电容式压力传感器电路的温度补偿

本文提出了一种电容式压力传感器的温度补偿方法，它适用于在不同输入压力下的温度补偿。本文设计的相应的补偿电路，经高低温测试，其补偿效果良好，对变送电路的输出输入关系也作了推导。     

基于神经网络技术的虚拟传感器温度补偿系统

介绍了一体化虚拟温度传感器补偿仪,运用多传感器数据融合技术与神经网络技术,与虚拟仪器技术相结合创建了虚拟压阻式传感器的温度补偿系统。实验结果表明,该方法有效地抑制干扰因素,获得高稳定性测量结果。     

WIA-PA无线温度变送器的设计与实现

针对某些工业现场布线困难和分布分散等问题,设计了一种基于WIA-PA技术以高性能、低功耗的16位微控制器MSP430F5438A为核心的无线温度变送器。搭建了热电偶测温电路,对热电偶进行冷端补偿,设计无线模块和温度采集模块的通信程序,并对温度采集进行测试。测试结果表明,该无线温度变送器通信稳定可靠,且测量精度能保持在5‰以内。     

低压变频器中的温升及其试验方法

低压变频器（交流进线l000V以下）越来越广泛的深入到人们的生活和生产中，我们正确认识及使用变频器，尤其是其工作环境以及散热问题，对变频器的可靠性的影响是非常大的。本文分析了变频器发热的主要原因，并重点介绍了变频器的温升重点部位及试验方法，以利于变频器用户掌握了解变频器温升及温升试验。     

LEM电流传感器的应用探讨

介绍了LEM电流传感器的特性和实际应用的经验。电流实时检测技术广泛地应用在工业领域,由于受到传统方法限制,其技术成本较高。随着科学技术的发展与进步,新型的基于霍尔效应电流传感器应运而生,它可以实现零到数十安培甚至高达数千安培的电流动态检测,不但在检测电流范围上实现了突破,而且在动态性能上也有显著的提高,同时还对检测回路与主回路进行了完全隔离。因而,在电力电子行业电流检测中得到越来越广泛地应用。     

A Zero-Heat-Flow Transducer for Monitoring Perfusion Blood Temperature

The transducer in which the zero-heat-flow method was applied is designed for monitoring the blood temperature flowing in a tube. The circumference of the probe was heated or cooled to the same temperature as the tube-surface temperature which finally showed the blood temperature, so that the net heat flow across the probe was reduced to zero. Experiments showed that the water temperature could be measured from the surface of a vinyl-chloride tube with the accuracy of ±0.2°C between 20 and 400°C of water temperature. The measured temperature was not affected by the ambient temperature, tube thickness, tube material, and flow rate. Time delay of ramp-like change in the water temperature was around 2 min to measure on the vinyl-chloride tube. Time delay depends on the heat capacity of the metal frame, the thermal conductivity of the tube material, and the power of thermomodule. The in vivo experiment of this device appeared to be satisfactry with a high accuracy and good response time.