高温下Pt-13Rh/Pt热电偶的热电动势衰减机理研究  

Study on the Attenuation Mechanism of Thermocouple Electromotive Force of Pt-13Rh/Pt at High Temperature

作　　者：熊雅玲 陆玖鹏 耿怀亮 李雪娇 梅若冰 XIONG Ya-ling;LU Jiu-peng;GENG Huai-liang;LI Xue-jiao;MEI Ruo-bing(Nanjing University of Science&Technology,Nanjing 210094,China;Wuxi International Platinum Co.Ltd.,Wuxi 214194,Jiangsu,China)

机构地区：[1]南京理工大学,南京210094 [2]无锡英特派金属制品有限公司,江苏无锡214194

出　　处：《贵金属》2020年第2期7-10,15,共5页Precious Metals

摘　　要：模拟1400℃富含Pt-Rh的使用环境,研究R型热电偶(Pt-13Rh/Pt)在高温下的衰减机理。分析竹节状缩颈现象的形成原因,讨论引起热电动势衰减的因素。结果表明,在富含气相Pt-Rh的高温环境下,热电偶外瓷珠表面沉积了固态的Pt、Rh,导致绝缘电阻的降低以及实际测温点向低温区转移,最终导致热电动势衰减。By simulating the operating environment of type R thermocouple(Pt-13Rh/Pt)with rich Pt-Rh gas phase at 1400°C,the attenuation mechanism of thermocouple at high temperature was studied.The causes of the bamboo-like necking phenomenon are analyzed and the factors induced the attenuation of thermal electromotive force(EMF)are discussed.The results showed that solid platinum and rhodium were deposited on the surface of the outer porcelain beads of the thermocouple in high temperature environment which was rich in gas phase platinum and rhodium.This leaded to a decrease in insulation resistance and a shift of the actual temperature measuring point to a lower temperature region,which ultimately resulted in the attenuation of EMF.

关 键 词：金属材料 R型热电偶 高温 热电动势 衰减机理 

分 类 号：TG146.3[一般工业技术—材料科学与工程]