Development of an optical thermal history coating sensor based on the oxidation of a divalent rare earth ion phosphor

Yáñez-González, Álvaro; Ruiz-Trejo, Enrique; van Wachem, Berend; Skinner, Stephen; Beyrau, Frank; Heyes, Andrew

Abstract

The measurement of temperatures in gas turbines, boilers, heat exchangers and other components exposed to hot gases is essential to design energy efficient systems and improve maintenance procedures. When on-line measurements, such as those performed with thermocouples and pyrometers, are not possible or inconvenient, the maximum temperatures of operation can be recorded and measured off-line after operation. Although thermal paints have been used for many years for this purpose, a novel technique based on irreversible changes in the optical properties of thermographic phosphors, can overcome some of the disadvantages of previous methods.

In particular, oxidation of the divalent rare earth ion phosphor BaMgAl10O17:Eu (BAM:Eu) has shown great potential for temperature sensing between 700 °C and 1200 °C. The emission spectra of this phosphor change with temperature, which permits to define an intensity ratio between different lines in the spectra that can be used as a measurand of the temperature. In this paper, the study of the sensing capabilities of a sensor coating based on BAM:Eu phosphor material is addressed for the first time. The sensitivity of the intensity ratio is investigated in the temperature range from 800 °C to 1100 °C, and is proved to be affected by ionic diffusion of transition metals from the substrate. The use of an interlayer made of zirconia proves efficient in reducing ionic diffusion and coatings with this diffusion barrier present sensitivity comparable to that of the powder material.

Citation

Yáñez-González, Á., Ruiz-Trejo, E., van Wachem, B., Skinner, S., Beyrau, F., & Heyes, A. (2016). Development of an optical thermal history coating sensor based on the oxidation of a divalent rare earth ion phosphor. Measurement Science and Technology, 27(11), Article 115103. https://doi.org/10.1088/0957-0233/27/11/115103

• Journal Article Type: Article
• Acceptance Date: Aug 24, 2016
• Online Publication Date: Sep 22, 2016
• Publication Date: 2016-11
• Deposit Date: Feb 8, 2021
• Publicly Available Date: Feb 8, 2021
• Journal: Measurement Science and Technology
• Print ISSN: 0957-0233
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 27
• Issue: 11
• Article Number: 115103
• DOI: https://doi.org/10.1088/0957-0233/27/11/115103
• Keywords: Instrumentation; Applied Mathematics
• Public URL: https://hull-repository.worktribe.com/output/3713542
• Publisher URL: https://iopscience.iop.org/article/10.1088/0957-0233/27/11/115103
• Related Public URLs: https://strathprints.strath.ac.uk/58762/
• Additional Information: Journal title: Measurement Science and Technology; Article type: paper; Article title: Development of an optical thermal history coating sensor based on the oxidation of a divalent rare earth ion phosphor; Copyright information: © 2016 IOP Publishing Ltd; Date received: 2016-03-12; Date accepted: 2016-08-24; Online publication date: 2016-09-22