Long Duration Testing of Type C Thermocouples at 1500 DGC.

Rempe, J. L. ; Knudson, D. L. ; Daw, J. E. ; Wilkins, S. C.

Technical Information Center Oak Ridge Tennessee

关键词: Type C thermocouples;    Testing;    Temperature range;    Long duration test;    Oxygen ingress;   

RP-ID  :  DE2008936619

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Experience with Type C thermocouples operating for long periods in the 1400 to 1600 DGC temperature range indicate that significant decalibration occurs, often leading to expensive downtime and material waste. As part of an effort to understand the mechanisms causing drift in these thermocouples, the Idaho National Laboratory conducted a long duration test at 1500 DGC containing eight Type C thermocouples. As report in this document, results from this long duration test were adversely affected due to oxygen ingress. Nevertheless, results provide key insights about the impact of precipitate formation on thermoelectric response. Post-test examinations indicate that thermocouple signal was not adversely impacted by the precipitates detected after 1,000 hours of heating at 1,500 DGC and suggest that the signal would not have been adversely impacted by these precipitates for longer durations (if oxygen ingress had not occurred in this test).