A gas detection element for detection of a measurement target gas is provided. The gas detection element includes a gas detection layer including a chemochromic pigment; and a spacer. The spacer is permeable to the measurement target gas, is disposed on a first surface of the gas detection layer, and has an area smaller than an area of the gas detection layer.

According to one embodiment, a sensor includes a base, first and second detection element portions, first to third resistor terminals, and first and second conductive terminals. The base includes first and second base regions. The first detection element portion is provided at the first base region. The first detection element portion includes a first detection dement. The first detection dement includes a first resistance member and a first conductive member. The first resistance member includes a first resistance portion and other portion. The first conductive member includes a first conductive portion and other portion. The second detection element portion is provided at the second base region. The second detection dement portion includes a second detection element. The second detection element includes a second resistance member and a second conductive member. The second resistance member includes a second resistance portion and other portion. The second conductive member includes a second conductive portion and other portion.

Methods and apparatus for sensing hydrogen in a mixture of hydrogen and natural gas are provided. One example of the apparatus comprises: a first chamber for receiving air; a second chamber for receiving the mixture of hydrogen and natural gas; a first electrode for adsorbing oxygen molecules from air in the first chamber and for reducing the oxygen molecules to oxide ions; a second electrode; an ionic conductor for transporting the oxide ions from the first electrode to the second electrode in order to cause the transported oxide ions to combine with hydrogen molecules at the second electrode; sensing circuitry for sensing an electrical parameter associated with the combination of the transported oxide ions with the hydrogen molecules at the second electrode; and processing circuitry configured to determine a proportion of hydrogen in the mixture, based at least in part on the electrical parameter sensed by the sensing circuitry.

An air-quality detection apparatus is disclosed. The air-quality detection apparatus includes a casing body including a bottom and a side wall extending upwards from the circumference of the bottom, a first printed circuit board (PCB) disposed horizontally above the bottom, a temperature/humidity sensor mounted on the bottom surface of the first PCB, a second PCB disposed horizontally above the first PCB, and a CO.sub.2 sensor mounted on the second PCB.

Drill bit wear can be quantified through an analysis of chemical reactions that occur during drilling. A detector measures the molar composition of a dissolved gas sample. From the molar composition, the moles of hydrogen, ethylene, and propylene in the dissolved gas sample are determined. A thermal cracking reaction and a thermal decomposition reaction determine moles of hydrogen produced during drill bit wear based on the moles of ethylene and propylene. The moles of hydrogen produced is subtracted from the total moles of hydrogen to determine moles of hydrogen produced by metal oxidation. A metal-water reaction determines the moles of metal that have been oxidized. This can be converted into mass or volume of metal loss to quantify drill bit wear.

A hydrogen gas sensor utilizing electrically isolated tunneling magnetoresistive stress sensing elements is disclosed. The hydrogen gas sensor comprises: a deformable substrate, a magnetoresistive bridge stress sensor located on the deformable substrate, an electrical isolation layer covering the magnetoresistive bridge stress sensor, a magnetic shielding layer located on the electrical isolation layer, and a hydrogen sensing layer located above the deformable substrate. The hydrogen sensing layer is located in a plane perpendicular to the deformation of the substrate covering the electrical isolation layer. The hydrogen sensing layer is used for absorbing or desorbing hydrogen gas to generate expansion or contraction deformation and cause a stress change of the deformable substrate. The magnetoresistive bridge stress sensor is used for measuring a hydrogen gas concentration utilizing the stress change of the deformable substrate. It results in a hydrogen gas sensor with improved performance.

The invention relates to a sensor device (1) for detecting a gas (G), particularly a permanent gas such as H.sub.2, CO, CO.sub.2, CH.sub.4, comprising: an adsorption filter (30) comprising a body (2) consisting of a molecular sieve material, a sensing element (10) for detecting said gas (G), and a carrier (4) for carrying the sensing element (10), wherein the carrier (4) comprises an opening (50) via which said gas (G) to be detected can reach the sensing element (10), and wherein the adsorption filter (30) is connected, particularly glued, to the carrier (4) and closes said opening (50) so that said gas (G) to be detected can diffuse through said body (2) towards the sensing element (10).

A hydrogen gas sensor with a substrate and a zinc oxide nanostructured thin film deposited on the substrate, wherein the zinc oxide nanostructured thin film has a lattice structure with a weight ratio of low binding energy O.sup.2− ions to medium binding energy oxygen vacancies in a range of 0.1 to 1.0, and a method of fabricating a gas sensor by thermally oxidizing a metal thin film under low oxygen partial pressure. Various combinations of embodiments of the hydrogen gas sensor and the method of fabricating the gas sensor are provided.

Disclosed is a gas sensor. The gas sensor comprises: a substrate; a thermoelectric layer which is disposed on the substrate and has a metal nanowire; a first electrode and a second electrode disposed to be spaced apart from each other on the thermoelectric layer; and a catalyst layer which is disposed on the first electrode and has a composite structure in which a metal particle is bonded to a carbon structure.

A method for determining a gas concentration in a cavity including: exciting a resistance sensor element situated in the cavity with an input signal, measuring an output signal of the resistance sensor element, determining a first parameter of a transfer function based on the input signal and the output signal, determining a second parameter of the transfer function based on the input signal and the output signal, checking a plausibility of the first parameter based on the second parameter, and outputting an error signal in the case of lack of plausibility of the first parameter.