呼吸机加热湿化器温度控制电路设计

利用NE555集成电路和负温度系数(NTC)热敏电阻器设计了一种呼吸机用加热湿化器温度控制电路。阐述如何确定电路设计方案、选择适合的热敏电阻以及计算限流电阻的大小,并对加热湿化器样机温度稳定性进行了测试,结果表明其符合相关的呼吸机用加热湿化器国际标准。研究设计的温度控制电路具有一定的通用性。     

基于NTC热敏电阻器的实时PCR仪数据采集器设计

实时聚合酶链反应(PCR)是一种通过热循环与荧光信号检测方法实现特定DNA片段的快速复制与定量检测的技术.PCR反应过程中,热循环温度控制精度决定了PCR反应效率,从而直接影响定量检测的精度.根据非稳态传热原理,热量从基座传递到试液需要一定的时间,为了检测这一延迟时间对温控的影响,基于NTC热敏电阻器,采用USB总线和...     

NTC电阻测量及自动化校准研究

NTC电阻作为温度敏感元件,在气象观测领域得到了广泛的应用；温度传感器的校准,是探空仪生产的重要环节,直接影响传感器的测量精度和生产效能.采用独特的模拟电路设计和单片机相结合,直接测量相应温度点的NTC电阻值,极大地简化了以前的“电阻-频率-温度”之间的转换环节和标定工艺,从而根据测量的NTC电阻即可精确地计算出大气温度.     

夜用电子体温警示计的设计

设计了一种适合家庭和医院病房使用的夜用电子体温警示计.用热敏电阻器作感温元件,采用集成运算放大电路,以发光二极管(LED)作显示方式,只需通过看LED的颜色即可判断体温的基本状况.舌下测量时,可以在2～3 s内显示出病人发热的类型,腋下测量需8 s左右.该装置制作成本低廉、外型轻巧,适宜普及推广.     

Ceramic Based Resistive Sensors

This paper reviews the current status and research trends of two types of ceramic based resistive sensors, thermistors and gas sensors. The issues and challenges associated with their development for high temperature applications are examined and discussed. Worldwide research efforts in ceramic based resistive sensors, devoted mostly to resolve the issues of selectivity and stability, are also reviewed. These efforts tend to integrate the results obtained from both empirical and basic science approaches, and focus on various stages of sensor development, including development of new material systems, sensor fabrication and manufacturing techniques, and smart sensor arrays.     

钇铝石榴石上Mn-Co-Ni-O薄膜的制备及其相关特性表征

利用化学溶液法在具有良好导热性和红外透过性的钇铝石榴石单晶衬底上成功制备了具有单一尖晶石相的Mn1.56Co0.96Ni0.48O4薄膜.傅里叶红外光谱测试表明薄膜在2.5~5μm波段具有明显的吸收带.通过研究其电阻-温度关系并利用最近邻跳跃模型进行拟合,得到薄膜的特征温度约为2 530 K,室温下的负电阻温度系数约为-3.66%K-1.     

BaTiO_3系PTC热敏电阻施主加入物的研究

常用的施主加入物是Ｙ３＋和Ｎｂ５＋，施主掺入量一般控制在ｘ＝０．２％～０．３％为宜。影响施主掺入量的因素有原料纯度、烧结助剂、掺入施主的工艺等。研究了常用施主加入物的理化特性对ＰＴＣ热敏电阻性能的影响，提出了施主加入物的技术标准。     

热敏电阻不平衡电桥的简单设计技巧

不平衡电桥在热敏电阻测温电路中应用十分广泛。通过一些简单的设计技巧，实现了不平衡电桥输出的线性化。     

基于NTC热敏电阻的三种高精度测温系统研究

针对高精度测温的要求,提出了三种基于NTC热敏电阻的高精度测温系统。分别为恒压式测温系统,恒流式测温系统和双积分式测温系统。从系统构成、测温原理等方面对这三种测温系统进行了分析比较,指出各自特点。     

Local variability in PTC thermistor grain boundary structures

Scanning electron microscopy-based conductive mode (CM) microscopy, using the remote electron beam-induced current configuration, was carried out on a positive temperature coefficient of resistance thermistor at temperatures below and above the Curie temperature, T(C). Below T(C), when the thermistor is in a low resistance state, no strong CM contrast was observed. Above T(C) the thermistor grain boundaries become highly resistive and significant CM contrast formed owing to three mechanisms: all of the areas that were studied showed resistive contrast, but in addition some grain boundaries showed additional contrast due to electron beam-induced current, the origin of which was consistent with the presence of a back-to-back Schottky barrier structure at the grain boundary. Other grain boundaries exhibited additional contrast owing to beta-conductivity, which suggests a slightly different n-i-n grain boundary structure at these interfaces. These results suggest that electrically active grain boundaries with different structures coexist within the thermistor.