GAS SENSOR

PURPOSE:To accurately detect gas concentration in an atmosphere with an improved sensitivity by laying out a sintered lithium titanate body with a rhombic ramsdellite structure and estimating the resistance between electrodes. CONSTITUTION:A sintered lithium titanate (Li2Ti3O7) body 2 which has a rhombic ramsdellite structure and where the composition ratio of TiO2 to Li3O ranges from 73.0 to 76.0mol% is detected in a flat cylinder shape and platinum electrodes 3a and 3b are mounted on the upper surface with a certain fixed spacing, thus constituting the gas sensor 1. The sintered body 2 shows a change of 1-2 in terms of resistance (logarithmic) scale for a gas concentration within a range of 1% or less but shows almost no change for a gas concentration of 1% or more. Therefore, the sensor 1 responds to a reducing gas such as hydrogen gas with an extremely high sensitivity within a gas concentration of approximately 1% or less. Further, after the measurement ends, contact with a non-reducing gas causes the resistance to return to a value close to an initial value quickly.