Measurement of air moisture by the phosphorescence lifetime of a sol-gel based sensor

Air moisture is an important parameter in several industrial processes. Most of the sensors to measure air moisture are based on changes of the electrical properties of some materials. There are also optical sensors based on changes in the color and infrared sensor based on the high absorption of the water compared to other substances. In this paper, we present another type of optical sensor based on the measurement of phosphorescence lifetime of Al-Ferron in sol-gel support and using optical fibers to guide the light. The performance of the sensor has been evaluated by passing different wet streams through the sensor.