| 摘要 |
PURPOSE:To maintain substantial detection sensitivity with a slight amt. of gaseous hydrogen as well by providing a detecting element having the laminated structure consisting of a catalyst metal and solid compd. CONSTITUTION:The detecting element 1 has the laminated structure consisting of the catalyst metal 2 which consists of palladium, etc., and forms hydrogen atoms by the dissociation and adsorption of gaseous molecules upon receipt of the contact of hydrogen or gaseous hydrogen-contg. compd. and the solid compd. 3 consisting of tungsten trioxide. The element 1 is disposed into a chamber 8 having hermetic structure and the outdoor air which is the object of detection is introduced into the chamber. A dehumidifier 15 which dehumidifies the inside of the chamber 8 is provided. The humidity of the atmosphere in the chamber 8 where the element 1 is placed is decreased to approximately zero to prevent the deterioration of the catalyst activity by the humidity and to maintain the responsiveness of the sensor. The dissociation and adsorption of the hydrogen molecules to quickly induce the change of the quantity of light absorption are executed in the stage of the gas contact by the metal 2. The change of the quantity of the light absorption in the compd. 3 is obtd. with the high responsiveness even with a slight amt. of the hydrogen or gaseous hydrogen-contg. compd. |
