Opto-electronic humidity sensor with incident light in the form of a conical beam

Abstract

In the present work, an extensive experimental investigation of TiO₂ film has been carried out. TiO₂ films have been deposited on a prism base by using sol-gel spin process. As the humidity increases in the environment where such films are placed, physisorption and chemisorption of water take place through the pores of films. This leads to a corresponding modulation in the intensity of reflected light. Thus, relative humidity is estimated directly in terms of modulation in the intensity of light observed on a digital power meter. Surface morphology of TiO₂ films has also been studied.