Abstract: The infrared absorber 1 is provided with a finely structured metal layer 2 which causes local surface plasmon resonance by absorption infrared light; a dielectric layer 3 under the finely structured metal layer, and a metal layer 4 under the dielectric layer 3. The dielectric layer 3 is stacked between the layers 2 and 4 and consists of an organic polymer material having a molecular bond whose vibration is excited by infrared absorption. Further, the gas sensor is provided with the infrared absorber as the light source and/or the photodetector.

Abstract: A gasoline detecting device is provided with a suction nozzle arranged adjacent to an element to be inspected, a sensor for detecting gasoline within the sucked air arranged adjacent to the suction nozzle, and a body arranged in relation spaced from the suction nozzle. The body has a sensor drive unit for driving the sensor and for displaying the detection and a suction unit communicating with the suction nozzle. The gasoline detecting device can detect gasoline leakage from the element to be inspected.

Abstract: A gaseous carbon dioxide detection sensor comprising a detection electrode and a reference electrode opposed on both sides of an ionic conductor, wherein a mixture comprising one mol of an alkali metal carbonate more than one mol of an alkaline earth metal carbonate is used as the detection material for the detection electrode. The detection sensor has the electromotive force characteristic relative to the gaseous carbon dioxide less undergoing the effect of moisture in the gas to be measured and has a high sensitivity.