Development of an optical thermal history coating sensor based on the oxidation of a divalent rare earth ion phosphor
File(s)Yanez-Gonzalez_et_al.pdf (993.55 KB)
Accepted version
Author(s)
Type
Journal Article
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.
Date Issued
2016-09-22
Online Publication Date
2017-09-22T06:00:17Z
Date Acceptance
2016-08-24
ISSN
1361-6501
Publisher
IOP Publishing
Journal / Book Title
Measurement Science & Technology
Volume
27
Issue
11
Copyright Statement
© 2016 IOP Publishing Ltd. This is an author-created, un-copyedited version of an article accepted for publication in Measurement Science and Technology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at http://dx.doi.org/10.1088/0957-0233/27/11/115103.
Source Database
manual-entry
Subjects
Optics
Physical Sciences
Engineering
Publication Status
Published
Article Number
115103