Determination of pressure effect on thermocouple electromotive force using multi-anvil apparatus. Issue 2 (2nd April 2016)

• Record Type: Journal Article
• Authors: Nishihara, Yu; Fuke, Kazuki; Tange, Yoshinori; Higo, Yuji
• Is Part Of: High pressure research. Volume 36:Issue 2(2016)
• Page Start: 121
• Page End: 139
• Publication Date: 2016-04-02
• Subjects: Thermocouple -- multi-anvil apparatus -- chromel–alumel -- electromotive force -- pressure effect; High pressure (Science) -- Periodicals; High pressure (Technology) -- Periodicals; 536.41
• DOI: 10.1080/08957959.2016.1169275
• Languages: English
• ISSNs: 0895-7959

Abstract

ABSTRACT: We developed a method to determine the absolute pressure effect on thermocouple electromotive force (EMF), based on a single wire method using Kawai-type multi-anvil apparatus. In this method, pressure conditions along the wires were evaluated based on in situ X-ray diffraction using synchrotron X-ray radiation. The pressure effect of the Seebeck coefficients of chromel and alumel was determined up to 7 GPa and 600°C by the analyses of single wire EMFs and pressure-temperature profiles along the wires. The temperature correction for the type K thermocouple was calculated to be from 0°C to –3°C in the studied conditions. Since the multi-anvil apparatus is capable of achieving much higher pressure and temperature, the method presented in this study promises to reveal absolute temperature correction for thermocouples over a wide range of pressure and temperature conditions.