Abstract: A gas alarm device is provided, where a heating control section extends a heating period of time of a heater section if a first determination section determines that electrical characteristics of a sensing section of a gas sensor satisfy a first condition, and continues extension of the heating period of time of the heater section according to a determination result, by a second determination section, of whether or not the electrical characteristics upon lapse of extension of the heating period of time satisfy a second condition, and a gas detection section determines, according to the electrical characteristics upon lapse of extension time, that detection target gas is detected.

Abstract: A gas alarm for detecting a target gas based on a resistance value of a sensor element comprises a measuring unit to measure a characteristic value of the sensor element, a heating control unit to control a heater to perform a heating process to heat the sensor element, a determining unit to determine, based on the characteristic value, whether the sensor element is in a blunt state in which sensitivity of the sensor element is decreased, and an aborting control unit to abort the heating process to determine whether the sensor element is in the blunt state when a characteristic value of the sensor element measured by the measuring unit after beginning of the heating process by the heating control unit meets a predetermined condition.

Abstract: A core-shell structure (a diameter is about 5 nm) is located on an Al2O3 catalyst support. Platinum (Pt metal) is a core, and a shell that surrounds the core has a solid solution structure (A1-xBxOY) (where X is a composition that composes A and B, and Y is a composition of oxygen (O)) that is composed of platinum, palladium, and oxygen.

Abstract: A gas alarm for detecting a target gas based on a resistance value of a sensor element comprises a measuring unit to measure a characteristic value of the sensor element, a heating control unit to control a heater to perform a heating process to heat the sensor element, a determining unit to determine, based on the characteristic value, whether the sensor element is in a blunt state in which sensitivity of the sensor element is decreased, and an aborting control unit to abort the heating process to determine whether the sensor element is in the blunt state when a characteristic value of the sensor element measured by the measuring unit after beginning of the heating process by the heating control unit meets a predetermined condition.

Abstract: A gas alarm device is provided, where a heating control section extends a heating period of time of a heater section if a first determination section determines that electrical characteristics of a sensing section of a gas sensor satisfy a first condition, and continues extension of the heating period of time of the heater section according to a determination result, by a second determination section, of whether or not the electrical characteristics upon lapse of extension of the heating period of time satisfy a second condition, and a gas detection section determines, according to the electrical characteristics upon lapse of extension time, that detection target gas is detected.

Abstract: A gas sensor includes an adsorption layer configured to cause gas to adsorb thereon, the gas including a target gas and a non-target gas, and a sensor layer covered with the adsorption layer and having an electric characteristic thereof changing in response to density of the target gas passing through the adsorption layer, wherein the adsorption layer is made of a material whose primary component is a metal oxide having gold particles attached thereto.

Abstract: A core-shell structure (a diameter is about 5 nm) is located on an Al2O3 catalyst support. Platinum (Pt metal) is a core, and a shell that surrounds the core has a solid solution structure (A1-xBxOY) (where X is a composition that composes A and B, and Y is a composition of oxygen (O)) that is composed of platinum, palladium, and oxygen.