In order to provide an absorbance analysis apparatus for DCR gas that can measure a concentration of a DCR gas by separating absorbance of the DCR gas alone even in a mixed gas consisting of the DCR gas and CO gas whose absorption spectrum overlaps each other, the absorbance analysis apparatus for DCR gas comprises a DCR filter 31 that is configured to transmit a light in a first wavenumber domain including an absorbance peak of the DCR gas, a CO filter 32 that is configured to transmit a light in a second wavenumber domain that is different from the first wavenumber domain, and a DCR gas volume calculator 4 that is configured to calculate volume of the DCR gas based on a first absorbance measured by the light transmitted through the DCR filter 31 and a second absorbance measured by the light transmitted through the CO filter 32.

A multi-channel gas sensor comprising a gas cell (101, 601), a light source (110, 210, 310, 410, 510, 610), a first interference filter (150, 250, 350, 450, 550, 650), a first detection unit (120, 220, 320, 420, 520, 620) and a second detection unit (130, 230, 330, 430, 530, 630). The light source (110, 210, 310, 410, 510, 610) is arranged to emit light radiation into the gas cell (101, 5 601). The first detection unit (120, 220, 320, 420, 520, 620) is arranged to detect light from the light source, that has propagated through at least a part of the gas cell (101, 601), and that has been transmitted through the first interference filter (150, 250, 350, 450, 550, 650). The second detection unit (130, 230, 330, 430, 530, 630) is arranged to be illuminated by light from the light source that has been reflected in the first interference filter (150, 250, 350, 450, 10 550, 650) and then has propagated through the gas cell (101, 601) before illuminating the second detection unit and to detect at least a second wavelength portion of said light that has been reflected in the first interference filter.

A multi-channel gas sensor comprising a gas cell (101, 601), a light source (110, 210, 310, 410, 510, 610), a first interference filter (150, 250, 350, 450, 550, 650), a first detection unit (120, 220, 320, 420, 520, 620) and a second detection unit (130, 230, 330, 430, 530, 630). The light source (110, 210, 310, 410, 510, 610) is arranged to emit light radiation into the gas cell (101, 5 601). The first detection unit (120, 220, 320, 420, 520, 620) is arranged to detect light from the light source, that has propagated through at least a part of the gas cell (101, 601), and that has been transmitted through the first interference filter (150, 250, 350, 450, 550, 650). The second detection unit (130, 230, 330, 430, 530, 630) is arranged to be illuminated by light from the light source that has been reflected in the first interference filter (150, 250, 350, 450, 10 550, 650) and then has propagated through the gas cell (101, 601) before illuminating the second detection unit and to detect at least a second wavelength portion of said light that has been reflected in the first interference filter.

A system for real-time detection of airborne pathogens is disclosed. The system includes: an air intake unit defining an inlet and an air inflow channel; a fan configured to cause air in a sampling environment to flow into the air inflow channel via the inlet; a cooling unit for cooling air in the air inflow channel; a collection chamber for collecting liquid water condensed from air in the air inflow channel, the collection chamber including: an active target substrate having a surface that is coated with bioreceptors; and a reference target substrate that is not coated with bioreceptors, and an optical detection unit that is configured to independently illuminate the active target substrate and the reference target substrate with light for detecting presence of an airborne pathogen.

A system for real-time detection of airborne pathogens is disclosed. The system includes: an air intake unit defining an inlet and an air inflow channel; a fan configured to cause air in a sampling environment to flow into the air inflow channel via the inlet; a cooling unit for cooling air in the air inflow channel; a collection chamber for collecting liquid water condensed from air in the air inflow channel, the collection chamber including: an active target substrate having a surface that is coated with bioreceptors; and a reference target substrate that is not coated with bioreceptors, and an optical detection unit that is configured to independently illuminate the active target substrate and the reference target substrate with light for detecting presence of an airborne pathogen.

The invention relates to a device for measuring, in near-real-time, the level of black carbon, brown carbon, organic carbon, total carbon and CO.sub.2 in air. The device also provides for a direct calculation of aerosol angstrom coefficient as well as estimation of emissions rates of black carbon or brown carbon from nearby combustion sources.

The invention relates to a device for measuring, in near-real-time, the level of black carbon, brown carbon, organic carbon, total carbon and CO.sub.2 in air. The device also provides for a direct calculation of aerosol angstrom coefficient as well as estimation of emissions rates of black carbon or brown carbon from nearby combustion sources.

A gas analysis system with an FTIR spectrometer preferably utilizes a long path gas cell, a narrow band detector, and an optical filter that narrows the detection region to measure hydrogen sulfide.

A gas analysis system with an FTIR spectrometer preferably utilizes a long path gas cell, a narrow band detector, and an optical filter that narrows the detection region to measure hydrogen sulfide.

There is described a method for detecting a given gas species present in a gaseous sample. The method generally has splitting a primary optical pulse into first and second optical pulses, the primary optical pulse having a duration and carrying optical power within an excitation spectrum encompassing at least one absorption spectral band of the given gas species, the first optical pulse being propagated across an optical gas filter unit containing an amount of the given gas species and attenuating the first optical pulse at the at least one absorption band, one of i) the primary optical pulse and ii) the first and second optical pulses being propagated across the gaseous sample, and temporally delaying the first and second optical pulses from one another; measuring signal values of the delayed optical pulses; and detecting the presence of the given gas species in the gaseous sample based on the signal values.