<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Au/Pt thermocouples are considered as an alternative to High Temperature Platinum Resistance Thermometers and are one of the prime candidates to replace them as the interpolating instrument of the International Temperature Scale of 1990 (ITS-90) in the temperature range between about 660 °C and 962 °C. This work presents the results of investigation of two Au/Pt thermocouples that used exclusively quartz glass (SiO2) as insulation material. Measurements in fixed points of Zn, Al, and Ag were realized on these thermocouples as well with interchanged inner insulation made of high purity aluminium oxide (Al2O3). The conducted experiments tested the performance of Au/Pt thermocouples with the use of different insulation materials. The measured electromotive forces were found to be sensitive to the replacement of the quartz glass by aluminium oxide as an insulation material of the Au/Pt thermocouples. This change of insulation has resulted in a temperature increase up to about 0.5 K measured at the freezing point of silver. The decreasing insulation resistance of quartz glass at higher temperatures is believed to be the source of thermoelectric instability.</p></abstract>

Au/Pt thermocouples are considered as an alternative to High Temperature Platinum Resistance Thermometers and are one of the prime candidates to replace them as the interpolating instrument of the International Temperature Scale of 1990 (ITS-90) in the temperature range between about 660 °C and 962 °C. This work presents the results of investigation of two Au/Pt thermocouples that used exclusively quartz glass (SiO2) as insulation material. Measurements in fixed points of Zn, Al, and Ag were realized on these thermocouples as well with interchanged inner insulation made of high purity aluminium oxide (Al2O3). The conducted experiments tested the performance of Au/Pt thermocouples with the use of different insulation materials. The measured electromotive forces were found to be sensitive to the replacement of the quartz glass by aluminium oxide as an insulation material of the Au/Pt thermocouples. This change of insulation has resulted in a temperature increase up to about 0.5 K measured at the freezing point of silver. The decreasing insulation resistance of quartz glass at higher temperatures is believed to be the source of thermoelectric instability.

Effects of Quartz Glass Insulation on Platinum Gold Thermocouples

Institute of automation, measurement and applied informatics, Faculty of Mechanical engineering

Measurement Science Review

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Effects of Quartz Glass Insulation on Platinum Gold Thermocouples"}

Au/Pt thermocouples are considered as an alternative to High Temperature Platinum Resistance Thermometers and are one of the prime candidates to replace them...

Effects of Quartz Glass Insulation on Platinum Gold Thermocouples

Published Online: Oct 07, 2019

Page range: 209 - 212

Received: May 02, 2019

Accepted: Aug 30, 2019

DOI: https://doi.org/10.2478/msr-2019-0027

Keywords
Au/Pt thermocouple, quartz glass insulation, insulation resistance

© 2019 Peter Pavlasek et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effects of Quartz Glass Insulation on Platinum Gold Thermocouples

Published Online: Oct 07, 2019

Page range: 209 - 212

Received: May 02, 2019

Accepted: Aug 30, 2019

DOI: https://doi.org/10.2478/msr-2019-0027

KeywordsAu/Pt thermocouple, quartz glass insulation, insulation resistance

© 2019 Peter Pavlasek et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Au/Pt thermocouple, quartz glass insulation, insulation resistance