Compact gas sensors
AssigneeSensera Inc.
InventorJaeseok Ryu
Life of this patent
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Abstract
Systems and methods herein provide low power non-dispersive infrared (NDIR) gas sensors. The gas sensors comprise a thin film plasmonic light source that produces a time modulated parallel light beam at multiple selected wavelengths. The parallel light beam from the light source passes through a gas chamber without using focusing or collimating optical components. The gas sensors are continuously self-calibrated against environmental changes, such as temperatures and relative humidity, and aging. The gas sensors are suitable for use in hazardous environments because their low power and small thermal mass reduces the risk of explosion. The gas sensors can be integrated into conventional mobile device platforms.
Claims24
A compact gas sensor, comprising:
- a gas cell containing one or more gas species to be measured;
- a light emitter to emit light at one or more emission wavelengths including a characteristic wavelength for at least one of the one or more gas species and a reference wavelength, the light emitter disposed to emit the light through the gas cell and including:
- a continuous conductive layer that is heated to thermally emit the light;
- a dielectric layer formed over the continuous conductive layer;
- and
- a patterned conductive layer formed over the dielectric layer, the patterned conductive layer including a plurality of relief structures to define a layered light emitting structure that emits the reference wavelength at a first peak and the characteristic wavelength at a second peak;
- a photodetector to generate a signal upon detection of the light emitted through the gas cell;
- and
- a computing device connected to the light emitter and the photodetector;
- wherein the computing device receives, at a first time, the signal from the photodetector, the signal comprising a first signal corresponding to a light intensity at the reference wavelength at the first time;
- wherein the computing device receives, at a second time, a second signal and a third signal from the photodetector, the second signal corresponding to a light intensity at the characteristic wavelength and the third signal corresponding to a light intensity at the reference wavelength at the second time;
- and
- wherein the computing device generates a calibrated second signal using the first signal and the third signal to measure a gas species from among the one or more gas species to compensate for a drift in the one or more emission wavelengths.
Dependencies are inferred from the claim text.