Decalibration of sheathed thermocouples

Conference · Thu Dec 31 23:00:00 EST 1981

OSTI ID:5218819

Anderson, R L; Lyons, J D; Kollie, T G; Christie, W H; Eby, R

The decalibration of sheathed thermocouples at high temperatures has been studied by a variety of methods including inhomogeneity testing, calibration, metallography, and an ion microprobe mass analyzer. The results clearly show that the sheathed thermocouple is a complex system at elevated temperatures and that the thermoelements can be contaminated by the diffusion of materials through the insulation from the sheath. Decalibration of base-metal thermocouples is more severe in stainless steel sheaths than in high-nickel alloy sheaths such as Inconel 600. Decalibration tests have been run on Chromel versus Alumel and Nicrosil versus Nisil in vacuum and in argon atmospheres with both sheathed assemblies and bare wire. The decalibrations of both types of thermocouples are similar under these conditions.

• Research Organization: Oak Ridge National Lab., TN (USA); Oak Ridge Y-12 Plant, TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5218819
• Report Number(s): CONF-820306-6; ON: DE82008839
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
ALLOYS
ALUMEL
ALUMINIUM ALLOYS
ARGON
ATMOSPHERES
CALIBRATION
CANNING
CHEMICAL ANALYSIS
CHROMEL
CHROMIUM ALLOYS
CONTROLLED ATMOSPHERES
CORROSION RESISTANT ALLOYS
DIFFUSION
ELEMENTS
FABRICATION
FLUIDS
GASES
INCONEL ALLOYS
ION MICROPROBE ANALYSIS
IRON ADDITIONS
IRON ALLOYS
IRON BASE ALLOYS
MANGANESE ALLOYS
MASS SPECTROSCOPY
MATERIALS WORKING
MEASURING INSTRUMENTS
METALLOGRAPHY
MICROANALYSIS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONDESTRUCTIVE ANALYSIS
NONMETALS
PLATINUM ALLOYS
PLATINUM BASE ALLOYS
PLATINUM METAL ALLOYS
RARE GASES
RHODIUM ALLOYS
SILICON COMPOUNDS
SPECTROSCOPY
STAINLESS STEELS
STEELS
TEMPERATURE EFFECTS
TESTING
THERMOCOUPLES