Combustible gas detection material, and combustible gas detection manner

摘要

PURPOSE:To detect an inflammable gas by the use of photo-signals by utilizing the change in the light absorptivity corresponding to the concentration of the gas of a specific metal oxide. CONSTITUTION:The light absorptivity of an oxide of Cr, Mn, Fe, Ao, Ni or Ru is changed through contact with an inflammable gas in the presence of oxygen. The reason is that, in the case of cobalt oxide, for example, oxygen removes electrons from the cobalt oxide when the surface of the cobalt oxide is in contact with the air, and the removed electrons are absorbed to the surface of the cobalt oxide as oxygen cathode ions. If an inflammable gas is mixed in the air at this time, the absorbed oxygen cathode ions react wit the inflammable gas, thereby oxidizing the inflammable gas and returning the electrons from the oxygen cathode ions to the oxide cobalt. Therefore, when the concentration of the inflammable gas is high, the density of electrons in the cobalt oxide becomes high, whereas, if the concentration of the inflammable gas is low, the density of electrons is decreased. Since the light absorptivity of the cobalt oxide is changed by the density of electrons, it can be resumed that the cobalt oxide shows the change of light absorptivity corresponding to the change of the concentration of the inflammable gas.