Abstract
A detection method of hydrogen leakage locations has been proposed and characterized. Platinum-supported tungsten trioxide (Pt/WO3) was utilized as a sensing material whose color changes from semi-transparent to blue in the presence of hydrogen gas. The Pt/WO3 thin film was coated on the glass plate by sol-gel technique and evaluated with the exposure to hydrogen gas squirting out of the test nozzle at the different leak rate. The colored area was determined with binary image processing of the differential picture before/after the hydrogen exposure. The colored area expanded quickly and reached to an plateau level after 30 s, suggesting the reaction took place quite fast even at room temperature. Furthermore, the colored area in the steady state became larger as the hydrogen leak rate increased. This relationship and response kinetics was significantly affected by the angular orientation of the imaging device. The proposed method would be applicable to the inspection of various equipments using hydrogen, such as fuel cells, hydrogen storage tanks and hydrogen engine systems.
