Disclosed herein is a method for determining a type and corresponding concentration of at least one gas in a multi-gas mixture, the method including: exposing a gas sensitive element of a gas sensor to the multi-gas mixture; modulating a drive signal supplied to a temperature control element of the gas sensor to cause a temperature of the gas sensitive element to change from an initial temperature; recording a transient impedance response of the gas sensitive element while the temperature of the gas sensitive element changes to obtain a transient impedance response that is characteristic of the multi-gas mixture; using the transient impedance response to determine a type and corresponding concentration of at least one gas in the multi-gas sample from a database including calibration data corresponding to the at least one gas. Also disclosed herein is a method of calibrating a multi-gas sensing system, a multi-gas sensing system, and related methods for determining a type and corresponding concentration of at least one gas in a multi-gas mixture.

A method for operating a gas sensor device, which is equipped with at least one gas-sensitive electrical sensor resistor, a heating element for the controlled heating of the sensor resistor, a detection element for detecting the resistance value of the sensor resistor, and a signal processing element for processing measuring signals. In the method, measurements are carried out in time intervals, in which the resistance value of the sensor resistor is detected as a measuring signal, and the sensor resistor is heated for each measurement, the heating element being operated discontinuously in heating intervals and each measurement being assigned a heating interval. Measurements are automatically carried out in predefinable time intervals, and additional measurements are initiatable at arbitrary times. The duration of the heating intervals assigned to the individual measurements being selected as a function of the time interval to the preceding heating interval.

A combustible gas sensor including a first sensing element having a catalyst and a heating element and electronic circuitry in operative connection with the heating element of the first sensing element to change a temperature thereof between a temperature above a temperature to catalyze oxidative combustion and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of a plurality of gas analytes of interest. The electronic circuitry being configured to determine a species of at least one of the plurality of gas analytes of interest from a first, dynamic output of the combustible gas sensor while the temperature of the first sensing element is changing. The electronic circuitry further being configured to determine a concentration of the species from a second output of the combustible gas sensor.

A method for analyzing a gas, where a sensitive metal oxide-containing layer is exposed to the gas, includes: reducing the temperature of the sensitive layer from a first temperature to a second temperature, the temperature of the sensitive layer being maintained essentially at the second temperature for a predetermined time period; increasing the temperature of the sensitive layer to a third temperature; measuring at least one electrical resistance value of the sensitive layer while the sensitive layer exhibits essentially the third temperature; and analyzing components of the gas based on the measured at least one electrical resistance value.

A control method for gas chemosensors having a sensitive layer, which comprises the steps of: a) measuring the resistivity of the sensitive layer at a particular moment, the sensitive layer being at a particular temperature; b) establishing a temperature profile to be applied to the sensitive layer, based on the resistivity value measured; c) obtaining the average temperature value across the temperature profiles applied to the sensitive layer during a time interval and comparing the average temperature with stored values to determine changes in the gas concentration. The invention also relates to a gas detection system comprising a gas chemosensor connected to control means connected to heating means associated with the sensitive layer, defining a control loop with sigma-delta topology.

A resistive particle sensor is described for detecting soot in the exhaust gas of an internal combustion engine, including a sensor element having two strip conductors, which extend spaced apart in meanders in parallel to one another in an area of the sensor element that may be exposed to the exhaust gas, and a resistance strip conductor, the two strip conductors each being capacitively connected via capacitor elements to the resistance strip conductor.

A combustible gas sensor for detecting an analyte gas includes a first element including a first electric heating element, a first support structure on the first electric heating element and a first catalyst supported on the first support structure and electronic circuitry in electrical connection with the first element. The electronic circuitry is configured to operate in a first mode in which the first element is operated at a first temperature at which the first catalyst catalyzes combustion of the analyte gas, and in a second mode wherein the first element is operated at a second temperature which is below the temperature at which the first catalyst catalyzed combustion of the analyte gas but at which Joule heating of the first element occurs. The electronic circuitry is further configured to measure a variable in the second mode related to a mass of the first element.

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.

A method includes applying heat to a metal oxide sensing element of a gas sensor, varying the heat applied to the metal oxide sensing element for at least a time interval, and measuring an electrical resistance of the metal oxide sensing element versus variation of the heat for a time interval. The measurement of electrical resistance of the metal oxide sensing element versus variation of the heat applied to the metal oxide sensing element is compared to a set of corresponding reference measurements associated with a plurality of different target gases. A further sensor parameter versus the variation of electrical resistance and variation of the heat applied is measured to obtain a three-dimensional trajectory corresponding to variation of the sensor resistance, the variation of said heat and the variation of the further sensor parameter. This comparing includes comparing the trajectory in three dimensions to a set of reference three-dimensional objects

A sensor is driven at a first heating power value. The sensor generates a sensing signal that is indicative of a sensed entity. A possible onset of a sensor contamination condition is detected as a function of the sensing signal generated by the sensor. If such detecting fails to indicate onset of a sensor contamination condition, the sensor continues to be driven at the first heating power value. However, if such detecting indicates onset of a sensor contamination condition, a protection mode is activated. In the protection mode, the sensor is driven at a second heating power value for a protection interval, where the second heating power value is lower than the first heating power value. Furthermore, the operation may refrain from supplying power to the sensor for a further protection interval, wherein the further protection interval is longer than the protection interval.