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US 2026/0079101 A1Published application
Apparatus for detecting nitrogen dioxide
AssigneesThe United States of America as represented by the Secretary of Commerce, The Regents of the University of Colorado, a body corporate
InventorsCaroline Womack, Rebecca Washenfelder, Steven Brown
Life of this patent
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Abstract
Embodiments of the present invention relate to an apparatus for measuring nitrogen dioxide having components, pump and power consumption suitable for use with an UAV. Embodiments of the present invention also relate to an apparatus for measuring vertical profiles of ambient nitrogen dioxide having components, pump and power consumption suitable for use with a rotary wing UAV.
Claims20
An apparatus for detecting nitrogen dioxide in an air sample, said apparatus comprising:
- an optical cavity comprising a bounded chamber configured to contain the air sample, wherein the optical cavity comprises an inlet for the air sample to enter the chamber and an outlet for the air sample to exit the chamber;
- a light source positioned to transmit light into the optical cavity chamber, wherein the transmitted light has a wavelength substantially overlapping an absorption wavelength of the nitrogen dioxide in the air sample;
- a parabolic mirror positioned to redirect the transmitted light from the light source into the optical cavity chamber;
- an optical resonator formed by a first mirror positioned on a first end of the optical cavity and a second mirror positioned on a second end of the optical cavity, wherein the redirected light from the parabolic mirror is transmitted into the optical cavity chamber through the first mirror, wherein the light transmitted into the optical cavity chamber is reflected between the first and the second mirrors to form an oscillating light beam, wherein at least a first portion of the oscillating light beam is transmitted out of the optical cavity chamber through the second mirror as an output light;
- a detector positioned at the second end of the optical cavity to measure an attenuation in the output light, wherein the detector generates a digital signal in response to the attenuation in the output light;
- an optical frame for mounting the optical cavity, the light source, the parabolic mirror, the first mirror and the second mirror;
- a platform positioned on the optical frame for mounting the detector and a power source;
- a plurality of clamps positioned on the platform to attach the platform and the optical frame to an unmanned aerial vehicle;
- a pump for transporting the air sample into the optical cavity through the inlet, wherein the pump pulls the air sample at a predetermined flow rate to provide a predetermined residence time for the air sample in the optical cavity chamber;
- a plurality of sensors positioned to measure the ambient temperature, flow rate of the air sample, pressure and temperature inside the optical cavity chamber;
- a temperature controller for setting a thermoelectric cooler at a predetermined temperature;
- a power distributor for distributing power to the plurality of sensors, the temperature controller, the light source, the detector, and the pump;
- and
- a processor for determining the amount of the nitrogen dioxide in the air sample, wherein the processor determines the amount of the nitrogen dioxide in the air sample from density and light extinction inside the optical cavity, wherein the processor determines the density inside the optical cavity from the digital signal generated by the detector, the chamber pressure and the ambient temperature.
11 more elements
An apparatus for detecting nitrogen dioxide in an air sample, said apparatus comprising:
- an optical cavity comprising a bounded chamber configured to contain the air sample, wherein the optical cavity comprises an inlet for the air sample to enter the chamber and an outlet for the air sample to exit the chamber;
- a light source positioned to transmit light into the optical cavity chamber, wherein the transmitted light has a wavelength substantially overlapping an absorption wavelength of the nitrogen dioxide in the air sample;
- a parabolic mirror positioned to redirect the transmitted light from the light source into the optical cavity chamber;
- an optical resonator formed by a first mirror positioned on a first end of the optical cavity and a second mirror positioned on a second end of the optical cavity, wherein the redirected light from the parabolic mirror is transmitted into the optical cavity chamber through the first mirror, wherein the light transmitted into the optical cavity chamber is reflected between the first and the second mirrors to form an oscillating light beam, wherein at least a first portion of the oscillating light beam is transmitted out of the optical cavity chamber through the second mirror as an output light;
- a detector positioned at the second end of the optical cavity to measure an attenuation in the output light, wherein the detector generates a digital signal in response to the attenuation in the output light;
- an optical frame for mounting the optical cavity, the light source, the parabolic mirror, the first mirror and the second mirror;
- a platform positioned on the optical frame for mounting the detector;
- a plurality of clamps positioned on the platform to attach the platform and the optical frame to an unmanned aerial vehicle;
- a pump for transporting the air sample into the optical cavity through the inlet, wherein the pump pulls the air sample at a predetermined flow rate to provide a predetermined residence time for the air sample in the chamber;
- a pressure sensor positioned downstream from the outlet to measure the pressure inside the chamber;
- a flow sensor positioned downstream from the outlet to measure flow rate of the air sample exiting the chamber through the outlet;
- a first temperature sensor for measuring a first temperature inside the optical cavity;
- a second temperature sensor positioned outside the optical cavity for measuring a second temperature;
- a temperature controller for setting a thermoelectric cooler at a predetermined third temperature;
- a power distributor for distributing a first portion of power from a power source to the pressure sensor, the flow sensor and the temperature controller, and a second portion of the power from the power source to a light source driver, the detector, the pump, the temperature sensor and the thermoelectric cooler, wherein the light source driver generates a predetermined current to the light source from the second portion of the power distributed from the power source;
- and
- a processor for determining the amount of the nitrogen dioxide in the air sample, wherein the processor determines the amount of the nitrogen dioxide in the air sample from density and light extinction inside the optical cavity, wherein the processor determines the density inside the optical cavity from the digital signal generated by the detector, the pressure measured by the pressure sensor and the second temperature measured by second temperature sensor.
14 more elements
An apparatus for detecting nitrogen dioxide in an air sample, said apparatus comprising:
- an optical cavity comprising a bounded chamber configured to contain the air sample, wherein the optical cavity comprises an inlet for the air sample to enter the chamber and an outlet for the air sample to exit the chamber;
- a light source positioned to transmit light into the optical cavity chamber, wherein the transmitted light has a wavelength of about 457 nm;
- a parabolic mirror positioned to redirect the transmitted light from the light source into the optical cavity chamber;
- an optical resonator formed by a first mirror positioned on a first end of the optical cavity and a second mirror positioned on a second end of the optical cavity, wherein the redirected light from the parabolic mirror is transmitted into the optical cavity chamber through the first mirror, wherein the light transmitted into the optical cavity chamber is reflected between the first and the second mirrors to form an oscillating light beam, wherein at least a first portion of the oscillating light beam is transmitted out of the optical cavity chamber through the second mirror as an output light;
- a detector positioned at the second end of the optical cavity to measure an attenuation in the output light, wherein the detector generates a digital signal in response to the attenuation in the output light;
- an optical frame comprising a plurality of rods and a plurality of plates positioned to form a rectangular cage, wherein the optical cavity, the light source, the parabolic mirror, the first mirror and the second mirror are mounted on the optical frame;
- a platform positioned on the optical frame for mounting the detector and a power source;
- a plurality of clamps positioned on the platform to attach the platform and the optical frame to an unmanned aerial vehicle;
- a pump for transporting the air sample into the optical cavity through the inlet, wherein the pump pulls the air sample at a predetermined flow rate to provide a predetermined residence time for the sample air in the chamber;
- a filter positioned upstream from the inlet to remove aerosol particles in the air sample;
- a pressure sensor positioned downstream from the outlet to measure the pressure inside the chamber;
- a flow sensor positioned downstream from the outlet to measure flow rate of the air sample exiting the chamber through the outlet;
- a first temperature sensor for measuring a first temperature inside the optical cavity;
- a second temperature sensor positioned outside the optical cavity for measuring a second temperature;
- a temperature controller for setting a thermoelectric cooler at a predetermined third temperature;
- a power distributor for distributing a first portion of power from the power source to the pressure sensor, the flow sensor and the temperature controller, and a second portion of the power from the power source to a light source driver, the detector, the pump, the temperature sensor and the thermoelectric cooler, wherein the light source driver generates a predetermined current to the light source from the second portion of the power received from the power distributor;
- a relay switch positioned to transmit an electrical signal from the temperature controller to the thermoelectric cooler, wherein the relay switch transmits the electrical signal from the temperature controller to the thermoelectric cooler when the temperature of the thermoelectric cooler is below the third temperature;
- and
- a processor for determining the amount of the nitrogen dioxide in the air sample, wherein the processor determines the amount of the nitrogen dioxide in the air sample from density and light extinction inside the optical cavity, wherein the processor determines the density inside the optical cavity from the digital signal generated by the detector, the pressure measured by the pressure sensor and the second temperature measured by second temperature sensor.
16 more elements
Dependencies are inferred from the claim text.