A team of researchers led by Prof. Kyung Chun Kim from Pusan National University, Korea, developed and tested a non-contact technique to measure oxygen concentration under high temperatures. The team described how a phosphorescent material's glow, or "phosphorescence," can be leveraged to measure oxygen concentration.

Figure 1: PNU developed a non-contact technique.

Figure 1 shows thatthe material in question was yttrium oxide doped with europium (Y2O3:Eu3+)—a phosphor, i.e., a material that emits light in response to radiation—which has a highly temperature-resistant crystalline structure. Like other phosphors, Y2O3:Eu3+ absorbs light energy and re-emits it at a lower frequency.

However, owing to its unique molecular arrangement with oxygen vacancies, its phosphorescence varies depending on the surrounding oxygen. This high sensitivity to oxygen makes Y2O3:Eu3+ a suitable non-contact luminescent probe.[1]

The team set up a two-dimensional (2D) temperature and oxygen concentration adjustable furnace with a quartz window (a window that allows light to pass freely in both directions) and used it to shine an ultraviolent (UV) LED light towards a Y2O3:Eu3+ tablet.

On measuring the resultant phosphorescence using a spectrometer, the team found that it was most sensitive to the oxygen concentration at a temperature beyond 450 °C for a wavelength of 612 nm. Beyond 450 °C, the sensitivity of Y2O3:Eu3+ to oxygen concentration increased with increasing temperature but decreased with an increase in the oxygen concentration.

Importantly, they also observed two properties of Y2O3:Eu3+ phosphorescence that could be used to measure oxygen concentration at 550 °C: its intensity and lifetime, i.e., the time it takes for Y2O3:Eu3+ to stop emitting light. [2]

Though measurements utilizing the latter had been barely extra correct, these findings demonstrated the general applicability of utilizing the phosphorescence of Y2O3:Eu3 at excessive temperatures.

Discussing these findings, Dr. Kim states that their “examine is the primary to develop an easy, non-contact, 2D methodology that may present technical assist for the efficiency enchantment of many industrial merchandises at excessive temperatures.”

What are the implications of those findings? Prof. Kim additional remarks that “this methodology can improve fundamental mechanism analysis and industrial manufacturing functions, which might assist us perceive unknown thermophysical phenomena in each day life and engineering.” [3]

References:

1. https://www.prnewswire.com/news-releases/novel-non-contact-oxygen-concentration-measurement-technique-developed-by-pusan-national-university-researchers-301598647.html
2. https://www.azosensors.com/news.aspx?newsID=15128
3. https://techsardar.com/novel-non-contact-oxygen-focus-measurement-method-developed/

Cite this article:

Sri Vasagi K (2022), New Non-Contact Oxygen Concentration Measurement Technique, Anatechmaz, pp. 365