Calibration coefficient of a heat-flow DSC; Part II. Optimal calibration procedure

One-point (Mettler) and many-point (Netzsch) heat flow calibration of a DSC is discussed. It is shown that the two types of calibration are the alternative extremes between quick but rough procedure and time-consuming but accurate one. One-point calibration compares a typical function k(T) at the melting point of indium with the measured value for particular DSC and multiplies k(T) by a scaling factor. Many-point calibration is based on general mathematical procedure, namely fitting a set of experimental values of sensitivity to a polynomial. The polynomial coefficients are evaluated by the method of least squares. Based on the relationship between the sensitivity of a thermocouple and calibration coefficient of a DSC sensor made from it, two-point heat flow calibration is suggested. This is an optimal calibration procedure, for the relationship contains only two unknown coefficients. An example of how to perform the two-point calibration with Netzsch-Proteus Software is described in the Appendix.     

小比距离密闭空腔爆炸爆后气体温度和压力测量技术研究

为实现空腔爆炸温度、压力变化趋势的准确测量,基于铠装K型热电偶和压力变送器,建立密闭空腔爆后气体温度、压力测量系统。设计密封隔热防护装置,将传感器的敏感端与信号调理模块分别安装在两个密封腔内,有效提高了传感器在大当量爆炸冲击条件下的存活率。在0.86m/kg^1/3比距离密闭空腔大当量爆炸条件下,对传感器及防护装置的性能进行考核验证,爆后测量采集到了有效的气体温度及压力变化历程,且传感器状态能够最终恢复至正常状态。测试结果表明,使用密封隔热安装的K型热电偶和压力变送器可以满足小比距离密闭空腔爆后气体静态温度、压力测量需求。     

铜-康铜热电偶的低温不均匀性实验研究

从冰点到液氮温度的宽低温区内,对随机选取的铜-康铜热电偶进行了重复性精度标定.测试结果表明,多次断偶重复焊接行为将产生约0.272 mV的标准差.这意味着在液氮条件下,温度测量过程的最大误差将达8.98 ℃.所以,对现场、尤其对深冷区的现场进行精确测温实验中出现的断偶故障,重新焊接后必须重新标定才能继续使用.     

火焰辐射及偶丝导热对热电偶测温影响的数值分析

本文利用层流同向扩散乙烯火焰的数值模拟结果,根据所得的火焰温度场、气体速度场、火焰辐射场,分析火焰辐射、热电偶偶丝导热对热电偶测温的影响.结果表明在火焰的低温区火焰辐射要大于节点向外辐射,节点得到的能量要高于节点损失的能量,因此在火焰的低温区节点温度要高于当地的气体温度;同时直径为100μm的热电偶存在较大的导热,对节点温度测量有较大的影响.     

SW-Ⅱ型数显温控XL-Ⅰ箱形高温炉的故障及维修方法

运用电学的基本原理,对数显温控高温炉的故障进行了分析,在实践中总结出各种故障的发生原因、特征现象及解决方法。     

Bondability analysis of bond pads by thermoelectric temperature measurements

To reduce cost and enhance reliability for microelectronics applications, a complete understanding of the thermosonic bonding process is required. In particular, the question of whether melting, diffusion, or significant heating occurs along the interface during friction has often been raised. We present results obtained with a new device based on thermoelectric temperature measurements to determine the temperature at the bond interface. In addition to the temperature information, the data characterizes the bonding process in real time on a micrometer scale. The basic principle of the developed apparatus is temperature measurement by an Au-Ni thermocouple fixed within the inside chamfer of a bonding capillary. Different bond substrates with high and low bond contact quality have been investigated. The thermoelectric temperature measurements very precisely determines the bonding behavior of the bond pads. A few nanometers surface contamination on a bond pad significantly reduces the temperature rise at the bond interface and therefore impairs bondability of the substrate. These results demonstrate the sensitivity and accuracy of the measurement principle. The apparatus is a powerful tool to measure the tribology of the bond system and to characterize the bondability of different bond pads.     

基于热电偶放大器芯片AD595的小型测温系统

热电偶放大器AD595将仪器放大器和热电偶冷接头补偿器全部集成在一块单片芯片上,产生一个10mV/℃的输出。采用AD595设计一个测量温度系统。该系统由热电偶放大器AD595、AD转换芯片AD574以及单片机P89C61X2BN和键盘显示芯片Zl G7290组成,用于光集成芯片的温度测量,也可以用于其他温度测量场合。     

应用积分法的发动机内壁瞬态温度测试研究

在传热学基本原理和能量守恒定律的基础上,本文提出了利用积分法求解航空发动机壁面导热的偏微分方程,进而实现对航空发动机内壁瞬态温度的测量。借助螺塞热电偶温度传感器和多路数据采集卡,建立了瞬态温度测量系统,利用氢氧焰模拟航空发动机内部瞬态高温源,分别得出了传感器和红外测温仪测得的发动机内壁表面温度变化曲线。实验结果表明该方...     

基于K型热电偶的电阻炉温控系统设计

电阻炉温度的检测和控制直接与能耗、生产效率、产品质量、安全生产等重大技术指标相关联.为了能快速、准确检测与控制电阻炉的温度,系统采用K型热电偶和MAX6675作为温度采集模块,以单片机SI℃89C52为核心,设计了一种基于K型热电偶电阻炉温度检测控制系统,包括系统的硬件电路与软件系统.经实验测试,系统控制精度达到0.5℃,且性能稳定,使用简便,符合设计的预期要求.     

铝靶激光热应力的实验研究

 用高温应变计和热偶计等诊断技术，研究连续波氧碘化学激光（CW/COIL）与铝合金板作用产生的激光热应力。当照射靶面激光强度约1 000 W/cm²时，激光热应力随靶厚的增加而快速减小。当激光辐照靶材厚度h＝1.00 mm、激光强度I＝640~980 W/cm²时，激光热应力随辐照靶面激光强度的增加而增大。两者的激光热应力－时间曲线随靶厚的减薄或随辐照靶面激光强度的增加而变得越来越复杂。当靶厚h≤2.50 mm，辐照靶面激光强度I≥800 W/cm²时，激光热应力强度超过激光辐照区材料断裂强度，萌生许多孔洞裂纹，引起材料断裂破坏。