New non-contact oxygen concentration measurement technique developed by researchers from Pusan National University
Researchers have developed a new method to accurately measure oxygen concentration in high temperature environments using an oxygen sensitive phosphor
BUSAN, South Korea, August 3, 2022 /PRNewswire/ — Oxygen plays a key role in various industrial processes, including combustion and energy conversion, which are involved in important areas such as fuel cells, automotive engines and gas turbines . Thus, accurate and real-time measurement of oxygen concentration is crucial for the flawless operation of these industries.
Researchers from Pusan National University have developed a non-contact method to accurately measure oxygen concentration under high temperature conditions using the phosphorescence of europium-doped yttrium oxide ( Y2O3:Eu3+), which is sensitive to oxygen concentration.
Unfortunately, existing oxygen concentration measurement technologies rely on contact measurements using probes, which cannot withstand high temperature environments. Moreover, despite the availability of a few optical temperature measurement technologies, the organometallic materials they use degrade at temperatures above 120°C.
To solve this problem, a team of researchers led by Prof. Kyung Chun Kim from Busan National University, Korea, has developed and tested a non-contact technique for measuring oxygen concentration at high temperatures. In their study, which was posted on April 19, 2022 and published in volume 364 of Sensors and actuators B: Chemical on August 01, 2022the team described how the glow of a phosphorescent material, or “phosphorescence”, can be harnessed to measure oxygen concentration.
The material in question was europium-doped yttrium oxide (Y2O3:EU3+) – a phosphor, i.e. a material that emits light in response to radiation – which has a very temperature-resistant crystalline structure. Like other phosphors, Y2O3:EU3+ absorbs light energy and re-emits it at a lower frequency. However, due to its unique molecular arrangement with oxygen vacancies, its phosphorescence varies depending on the surrounding oxygen. This great sensitivity to oxygen makes Y2O3:EU3+ an appropriate non-contact luminescent probe.
To investigate this property, the team set up a two-dimensional (2D) oven with adjustable temperature and oxygen concentration with a quartz window (a window that allows light to pass freely in both directions) and used to shine an ultraviolet (UV) LED light towards a Y2O3:EU3+ Tablet. By measuring the resulting phosphorescence using a spectrometer, the team found that it was more sensitive to oxygen concentration at a temperature above 450°C for a wavelength of 612 nm. Beyond 450°C, the sensitivity of Y2O3:EU3+ Oxygen concentration increases with increasing temperature but decreases with increasing oxygen concentration.
Importantly, they also observed two properties of Y2O3:EU3+ phosphorescence which could be used to measure the concentration of oxygen at 550°C: its intensity and its lifetime, i.e. the time it takes for Y2O3:EU3+ to stop emitting light. Although measurements using the latter were slightly more accurate, these results demonstrated the global applicability of using the phosphorescence of Y2O3:EU3 at high temperatures.
Discussing these findings, Dr Kim says: “Our study is the first to develop a simple, non-contact 2D method that can provide technical support for improving the performance of many high-temperature industrial products.”
What are the implications of these findings? Professor Kim further remarks: “This method can enhance basic research on industrial production mechanisms and applications, which help us understand the unknown thermophysical phenomena of everyday life and engineering.”
It’s safe to say that by virtue of its simplicity and accuracy, this method is likely to find a home in many fields and usher in a new era of oxygen concentration sensors!
Reference
Title of the original article: Two-dimensional visualization of the oxygen concentration field in a high temperature environment using phosphorus Y2O3:EU3+
Log: Sensors and actuators B: Chemical
DO I: https://doi.org/10.1016/j.snb.2022.131884
Email of the corresponding author: [email protected]
Lab webpage
http://fluid.pusan.ac.kr
http://www.epic.re.kr
ORCID-ID
0000-0002-7943-9774
About Pusan National University
Website: https://www.pusan.ac.kr/eng/Main.do
Media contact:
Jae-Eun Lee
[email protected]
82 51 510 7928
SOURCEPusan National University
Comments are closed.