Disclosed herein is a method of providing a structure having two electrodes connected by nanowires, exposing the structure to an analyte that can adsorb onto the nanowires, and passing an electrical current through the nanowires to heat the nanowires to desorb the analyte. Also disclosed herein is an apparatus having the above structure; a current source electrically connected to the electrodes, and a detector to detect the analyte.

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.

The delivery of fuel oil through a fuel oil delivery pipe is monitored to measure the flow rate, temperature, viscosity, density and dielectric constant of the fuel oil as it moves through the delivery pipe. The digital data signals from the sensors which are a function of the measured parameters are recorded in a memory. An IR sensor detects the presence of air in the pipe and prevents the data signals from being recorded. The actual total quantity of fuel oil delivered through the pipe is calculated based upon the recorded data signals, which may be adjusted to take into account the temperature of the fuel oil being delivered. A clock circuit generates a timing signal reflecting the date and time the measurements were taken. Information as to the quantity delivered and the time of delivery may be sent to a remote location.

A method for analyzing a gas mixture, in which a layer which is configured for the adsorption and/or absorption of components of the gas mixture is exposed to the gas mixture. The method includes cooling the layer from a first to a second temperature and heating the layer from the second to a third temperature. While the layer has the first, second, and third temperature, at least one electrical resistance value of the layer is measured. A method is described in which a first and second layer are exposed to the gas mixture. The first layer is cooled from a first to a second temperature and the second layer is cooled from a third to a fourth temperature. While the first layer has the first and second temperature and the second layer has the third and fourth temperature, at least one electrical resistance value of the respective layer is measured.

A method in which on a basis of sensor information of a MOX sensor captured at different operating temperatures in different freshness state determination cycles a freshness state of a food is determined. A further aspect relates to a method in which additional information relating to a food is determined. A storage container, a computer program product, and a household cooling appliance implement the above noted methods.

A method for operating a gas sensor device for ascertaining information about an air quality. The method includes: providing a gas sensor device including at least one gas-sensitive electrical sensor resistor, a heater for the controlled heating of the sensor resistor, a detection device for detecting the resistance value of the sensor resistor, and a signal processing device for the sensor signal; heating the sensor resistor using the heater alternatingly in a first heating mode in a first operating phase and a second heating mode in a second operating phase, each heating mode including a sequence of heating pulses so that the sensor resistor is heated at predetermined temporal intervals for a predetermined duration to a predetermined operating temperature, an essentially identical operating temperature being selected for the at least two different heating modes; detecting the resistance value of the sensor resistor and generating a sensor signal.

A gas detection apparatus (1) which includes a gas detection element (3) including a heat generation resistor (34); an energization control section (7) which switches the energization state of the heat generation resistor to alternately assume one of two resistance values corresponding to one of two set temperatures set in advance; and a casing member (90) which accommodates the gas detection element and has a gas inlet opening (92h). The gas detection apparatus further includes a humidity computation section (7) which computes the humidity of the object atmosphere based on a ratio of a high-temperature-time voltage VH to a low-temperature-time voltage VL; and a clogging determination section (7) which determines the degree of clogging of the gas inlet opening based on a change in the humidity computed by the humidity computation section.

A multi-gas analysis includes a semiconductor gas sensor driven by a constant resistance driver circuit with a driving current to obtain a sensing output of a gas in a gas sample. A processing unit is operable, based on a reference voltage from the constant resistance driver circuit associated with the driving current, in one of a gas-identification mode, where the gas is identified based on the sensing output obtained in response to fine variation of the operating temperature of the semiconductor gas sensor, and a gas-detection mode, where an analysis result indicative of the concentration of the gas is obtained based on the sensing output obtained in response to an optimal operating temperature of the semiconductor gas sensor.

A combustible gas sensor includes a first sensing element, which includes a catalyst and a heating element in operative connection with the catalyst to heat the catalyst above a temperature to combust gas analytes of interest, and electronic circuitry in operative connection with the heating element of the first sensing element to periodically cycle the first sensing element between a temperature above the temperature to combust the analytes of interest and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of the analytes of interest. The electronic circuitry is adapted to determine a species of at least one of the gas analytes of interest from a first output of the combustible gas sensor during an ON time within a cycle duration. The electronic circuitry is further adapted to determine a concentration of the species of gas from a second output of the combustible gas sensor.

A process and electronic hardware and software system for rapidly heating and cooling an active sensing layer of a gas sensor is provided. A series of high-energy pulses is run through a CNT electrically-active layer, heating the layer to varying temperatures. The influence by various gases on the electrical conductivity of the layer can be used to identify gases (e.g., water vapor, alcohol, methane, O.sub.2, CO.sub.2, and CO). Advantageously, the same structure can also be used as a nanoheater, either within or outside the context of the gas sensor. The device can acquire a unique gas spectra in seconds, and thus accurately determine gas type and mixtures of gases based on a library of known spectra.