초록 ▼

A gas measurement method for metal-oxide gas sensors. The sensors are thermally cycled by sequential heating and cooling. It has been found that a continuous, concentration-dependent, unique signature for different gases is produced during thermal cycling. Once signature patterns are developed for d

A gas measurement method for metal-oxide gas sensors. The sensors are thermally cycled by sequential heating and cooling. It has been found that a continuous, concentration-dependent, unique signature for different gases is produced during thermal cycling. Once signature patterns are developed for different concentrations, an unknown gas concentration for which a signature pattern exists may be sampled, either by amplitude or time-dependent samples, in order to identify the gas in its concentration.

대표청구항 ▼

A method of operating a metal-oxide semiconductor gas sensor comprising, (a.) calibrating a gas sensor by: (1) exposing a metal-oxide gas sensor to a range of known gas concentrations, said gas being of a type measurable by the sensor, (2) thermally cycling the gas sensor for each gas concentration,

A method of operating a metal-oxide semiconductor gas sensor comprising, (a.) calibrating a gas sensor by: (1) exposing a metal-oxide gas sensor to a range of known gas concentrations, said gas being of a type measurable by the sensor, (2) thermally cycling the gas sensor for each gas concentration, the thermal cycle having a heating interval and a cooling interval, (3) measuring and recording the ratio of sensor conductance at two times in the thermal cycle, then, (b.) mesuring an unknown gas sample by: (1) exposing the gas sensor to an unknown concentration of said particular gas while thermally cycling said gas sensor and measuring the ratio of sensor conductance at said two times in the thermal cycle, (2) determining the unknown gas concentration of said particular gas by comparing said ratio measured for the unknown concentration to the previously measured ratios for said gas concentrations in said range of concentrations.