Sol-gel based oxygen sensor and luminescence lifetime based instrumentation

In this paper, a phosphorescent sensor to measure oxygen is described based on Al-Ferron in a sol-gel probe. The long RTP lifetime of this oxygen sensing material and its large singlet triplet splitting allows the use of standard optoelectronic components in the development of the low-cost instrumentation presented. The main advantages over other techniques are an excellent sensitivity, selectivity and response time and the possibility to detect very low oxygen concentrations. The main advantage over other phosphorescent sensors is the relatively high sensitivity, which makes this sensor suitable to be employed with optical fibers. However the noise is very important and special precautions must be taken in order to increase the signal to noise ratio and in order to avoid parasitic signals. Moreover, four different combinations of light source and photodetector have been tested in order to determine their usefulness.