Determination of the Seebeck Coefficient of Thin-Film Thermocouples

Published

May 1, 1998

Author(s)

Kenneth G. Kreider, Dean C. Ripple, D P. DeWitt

Abstract

Thin-film thermocouples have been found useful in numerous applications ranging from thermal convertors, heat flux gages, and thermopiles to surface temperature sensors for turbine engine blades and diesel engine cylinders. Because of their small size (junctions as small as 10-⁶ mm³) fast response, and stability at high temperatures, many more applications are expected. Thin-film thermocouples can be fabricated from a broad range of electrical conductors, but even with the same composition as the wire thermocouple the thin films may have different thermoelectric coefficients. Also if the thin films are used to measure temperature differentials across short distances on the substrate and cannot be calibrated by standard procedures.A calibration test for thin films on 10 mm x 50 mm substrates using the comparison method from 700 C to 900 C with type S or the new highly accurate Pt/Pd wire thermocouple as the reference thermometer. The results of calibrating thin films of Pt, Pd, Rh, and Ir vs Pt wire on si and Al₂O₃ will be discussed, and an uncertainty calculation based on a heat transfer model of the test apparatus will be presented.

Proceedings Title

Proceedings of the 44 International Instrumentation Symposium

Conference Dates

May 3-7, 1998

Conference Title

International Instrumentation Symposium

Pub Type

Conferences

Keywords

surface temperature, temperature calibration, thermocouples, thermometry, thin films

Citation

Kreider, K. , Ripple, D. and DeWitt, D. (1998), Determination of the Seebeck Coefficient of Thin-Film Thermocouples, Proceedings of the 44 International Instrumentation Symposium (Accessed July 26, 2024)