Why can’t chemical analysis alone always solve failure problems? Chemical analysis of a failed thermocouple is often an important step in determining the cause of failure. Analysis of the wire, insulators and sheath can identify
What is the significance of a temperature gradient when there are “intermediate materials” in the thermocouple circuit? For the purpose of this blog, “intermediate materials” is defined as a portion of a thermocouple circuit that has a
What does the “Certificate of Thermoelectric Calibration” represent? A “Certificate of Thermoelectric Calibration” is provided by Concept Alloys for all pairs of matched thermocouple materials that are intended to meet an accepted nominal emf vs.
What does the "initial calibration tolerance" mean? Materials for “letter designated thermocouples” (as designated by ASTM) and certain other common thermocouple types are produced to meet nominal emf vs. temperature curves that are accepted by
The Customer's Problem The customer experienced wire breakage problems with tungsten-rhenium thermocouples and submitted a sample for failure analysis.The Findings / AnalysisThe thermocouple was deconstructed and the failed section was prepared for chemical analysis. Analysis
Failed Type J Thermocouple Analysis The Customer's ProblemThe customer submitted a failed Type J Thermocouple reported to have developed an open circuit after extended time at temperature. Initial evaluation confirmed the open circuit.The Findings / AnalysisSectioning