A method and a gas sensor arrangement for determining an absolute gas concentration with a gas sensor and a decomposing gas to be measured are disclosed. In an embodiment a method includes acquiring a first sensor signal and determining from the first sensor signal at least one initial data point, decomposing the gas to be measured using a means for decomposing the gas of the gas sensor arrangement, acquiring a second sensor signal and determining from the second sensor signal at least one decay data point and deriving an absolute gas concentration from a gas concentration function realized as a mathematical function by evaluating the gas concentration function at least for the at least one initial data point and the at least one decay data point.

An apparatus for measuring a concentration of a target gas includes: a gas sensor including a sensing layer having an electric resistance that changes by an oxidation reaction or a reduction reaction between gas molecules and the sensing layer; and a processor configured to, in response to the target gas being introduced along with air into the gas sensor, monitor a change of the electric resistance of the sensing layer and determine the concentration of the target gas by analyzing a shape of the change of the electric resistance.

A gas detector comprises: plural gas sensors provided with a metal-oxide semiconductor whose resistance changes based upon contact with a gas; and a driving circuit for operating the gas sensors. The gas detector stores the ratio between initial resistance in air of the metal-oxide semiconductor and initial resistance of the metal-oxide semiconductor in an atmosphere including a predetermined concentration of fron gas, for the plural gas sensors. The gas detector learns resistance in air of the metal-oxide semiconductor in a gas sensor in use, and detects occurrence of fron gas when resistance of the metal-oxide semiconductor of the gas sensor in use becomes lower than a value corresponding to the learned resistance in air divided by the ratio. The gas detector counts the period that a first gas sensor is used. When the first gas sensor has been used for a predetermined period, both the first gas sensor and a second gas sensor are used for a learning period to continue detection of fron by the first gas sensor and to learn the resistance in air of the metal-oxide semiconductor of the second gas sensor. After completion of the learning period, fron leakage is detected by the second gas sensor.

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.

A gas sensor includes: a first thermistor having a resistance value that changes according to a concentration of a first gas with a first sensitivity and changes according to a concentration of a second gas with a second sensitivity; a second thermistor connected in series to the first thermistor, the second thermistor having a resistance value that changes according to a concentration of the first gas with a third sensitivity that is lower than the first sensitivity and changes according to a concentration of the second gas with a fourth sensitivity that is different from the second sensitivity; and a correction resistor connected in parallel with the first or second thermistor.

A sensor system includes a sensing element that includes a sensing material and electrodes configured to apply a first electrical stimuli to the sensing material at an electrical excitation frequency, a modifier assembly including one or more circuits configured to change an electrical impedance of the sensing element, and one or more processors configured to control the modifier assembly. Responsive to exposure of gas to the sensing element, the one or more processors change a linearity of a first electrical signal received from the sensing element by changing the electrical impedance of the sensing element and applying a second electrical stimuli to the sensing material at the electrical excitation frequency.

A gas sensing device includes chemo-resistive gas sensors; heating elements for heating each of the gas sensors; an information extraction block for receiving signal samples and for generating representations for the received signal samples; and a decision making block configured for receiving the representations, wherein the decision making block comprises a weighting block and a trained model based algorithm stage, wherein the weighting block receives feature samples of the representations and applies time-variant weighting functions to the feature samples of the respective representation in order to calculate a weighted representation including weighted feature samples.

An electronic device is disclosed. The electronic device comprises: a gas sensor having different sensitivities in temperature for each of a plurality of gases; and a processor for calculating a concentration of at least one of a plurality of gases on the basis of an output value of the gas sensor for different temperature sections.

An olfactometer or electronic nose is able to vary a plurality of operating parameters during a test cycle in parallel, in accordance with a measurement protocol. This measurement protocol, and correspondingly the operating parameters to be varied, the values to be set for those parameters, and the timing of the variation in these values is tailored to most effectively distinguish between likely candidates in a particular testing scenario. A characterisation library is then used to match the results of the measurement protocol to the best target in the characterisation library. Test protocols and/or characterisation libraries may be downloaded from a remote server on demand, and certain activities may be carried out either locally or remotely.

A MEMS gas sensor includes a photoacoustic sensor including a thermal emitter and an acoustic transducer, the thermal emitter and the acoustic transducer being inside a mutual measurement cavity. The thermal emitter includes a semiconductor substrate and a heating structure supported by the semiconductor substrate. The heating structure includes a heating element. The MEMS gas sensor further includes a chemical sensor thermally coupled to the heating element, and the chemical sensor including a gas adsorbing layer.