不同退火工艺对贵金属热电偶热电性能的影响  

Effect of Different Annealing Processes on Thermoelectric Performance of Precious Metal Thermocouples

作　　者：成艾霖 薛丽倩 李凤 肖雨辰 胡晓峰 吴勇军 蔡翱 

机构地区：[1]重庆材料研究院有限公司,重庆400707 [2]重庆仪表功能材料检测所,重庆400707

出　　处：《中国仪器仪表》2020年第11期85-89,共5页China Instrumentation

基　　金：国家自然科学基金项目(61875023);重庆市技术创新与应用发展专项重点项目(cstc2019jscx-fxydX0024)资助。

摘　　要：热电偶的热处理状态对其测温及检定至关重要。依照国家标准,偶丝在测量前需进行通电退火来保证其测温准确性,而工业生产上常采用箱式炉退火成半硬态产品或按照客户需求出厂未退火的硬态产品。本文以同名极比较法分别测量了通电退火、箱式炉退火及未退火状态下的S型、R型和B型热电偶的热电动势,对比研究了不同退火工艺对贵金属热电偶热电性能的影响。结果表明,经通电退火的热电偶的热电动势在允差范围内时,采用箱式炉退火后退火不充分,导致S型和R型热电偶的热电动势偏低,而B型热电偶的热电动势偏高。The heat treatment of thermocouple is very important for its temperature measurement and verification.In accordance with the National Standard,electrified annealing is needed before the thermocouple is measured to ensure the accuracy of temperature measurement.In industrial production,the box furnace annealing is often used to produce semihard products and sometimes hard products which are not annealed are also needed according to customer’s demand.In this paper,the thermo-EMF of S-type,R-type and B-type thermocouples under the condition of electrified annealing,box furnace annealing and unannealed are measured by the method of samepolarity comparison.The effects of different annealing processes on the thermoelectric performance of precious metal thermocouples are compared and studied.Experimental results show that when the thermo-EMF of the thermocouple is within the tolerance range,the annealing in the box furnace is not enough,which results in the lower thermo-EMF of the S-type and R-type thermocouples and the higher thermo-EMF of the B-type thermocouples.

关 键 词：退火 贵金属热电偶 热电性能 热电动势 测温 

分 类 号：TH811[机械工程—仪器科学与技术] TG156.2[机械工程—精密仪器及机械]