In this study, WO3 metal oxide structure was investigated as an optical gas sensor. 90 nm WO3 thin films
were grown by RF magnetron sputtering on glass substrates. In order to obtain a sensitive layer for H2
gas, 10 nm Pt was coated on the top of WO3 film gas by the same technique. Optical absorbance variations
of Pt activated WO3 thin film gas sensor structure (Pt/ WO3) were measured at 40 C, 75 C and 125 C for
different Hydrogen concentration level of 1000 ppm 40.000 ppm. A tungsten halogen lamb and a CCD
spectrometer was used at optical gas sensor test system to measure optical absorbance of sensor realtime.