Methods and apparatus are presented for measuring a photoluminescence (PL) response, preferably a spatially resolved image of a PL response, from an object exposed to solar irradiation. In certain embodiments signals from the object are measured in two or more different spectral bands selected such that one of the measured signals has a higher PL component relative to ambient reflectance compared to another measured signal, enabling the PL component to be enhanced by a suitable differencing procedure. In other embodiments a signal from an object is measured in a spectral band selected such that at least 20% of the measured signal comprises PL generated from the object by the solar irradiation. The methods and apparatus have particular application to outdoor inspection of photovoltaic modules without having to modulate the operating point of the modules.

The present disclosure describes an apparatus for identifying a refrigerant fluid contained in a tank or in a measuring cell of a system for recharging an air-conditioning plant. The apparatus includes at least one infrared source configured to emit at least radiations with a first emitting intensity at a first wavelength and a second emitting intensity at a second wavelength. A first photodetector is configured to detect a first intensity of infrared radiations at the first wavelength, and a second photodetector is configured to detect a second intensity of infrared radiations at the second wavelength. A processing unit is configured to: calculate a ratio between the first intensity detected by the first photodetector and the second intensity detected by the second photodetector; and according to the Lambert-Beer law, obtain from said ratio a physical magnitude representative of the refrigerant fluid.

The present disclosure generally relates to a standalone gas extraction and detection system comprising a gas extraction chamber operable to receive a wellbore fluid and a carrier gas; a gas detection chamber in fluid communication with the gas extraction chamber, the gas detection chamber comprising reflective surfaces operable to receive infrared radiation (IR) and an extracted gas sample from the gas extraction chamber; an open-path detector operable to detect the IR in the gas detection chamber; and a shaft extending through the gas extraction chamber and the gas detection chamber of the standalone gas extraction and detection system.

A fluid sensor includes a substrate having a top main surface region, wherein the top main surface region of the substrate forms a common system plane of the fluid sensor, a thermal radiation emitter on the top main surface region of the substrate, an optical filter structure on the top main surface region of the substrate, a waveguide on the main top surface region of the substrate, and a thermal radiation detector on the top main surface region of the substrate, wherein the thermal radiation detector provides a detector output signal based on a radiation strength of the filtered thermal radiation received from the waveguide.

This invention relates to a method of and system for facilitating detection of a particular predetermined gas in a scene under observation. The gas in the scene is typically associated with a gas leak in equipment. To this end, the system comprises an infrared camera arrangement; a strobing illuminator device having a strobing frequency matched to a frame rate of the camera; and a processing arrangement. The processing arrangement is configured to store a prior frame obtained via the infrared camera arrangement; and compare a current frame with the stored prior frame and generate an output signal in response to said comparison. The system also comprises a display device configured to display an output image based at least on the output signal generated by the processing arrangement so as to facilitate detection of the particular predetermined gas, in use.

Device for improving an optical detecting smoke apparatus and implementing thereof. Apparatus and methods for detecting the presence of smoke in a small, long-lasting smoke detector are (disclosed. Specifically, the present disclosure shows how to build one or more optimized blocking members in a smoke detector to augment signal to noise ratio. This is performed while keeping the reflections from the housing structure to a very low value while satisfying all the other peripheral needs of fast response to smoke and preventing ambient light. This allows very small measurements of light scattering of the smoke particles to be reliable in a device resistant to the negative effects of dust. In particular, geometrical optical elements, e.g., cap and optical defection elements, are disclosed.

A device and method of use are provided for measuring the concentration of fatty acid methyl ester (FAME) in jet fuel to a limit of detection of 1 ppm. The device measures concentration of FAME in jet fuel via Fourier transform infrared spectroscopy (FTIR) with a spectral resolution of 1 cm.sup.−1. The device can use an infrared light emitting diode (IR LED) and mercury cadmium telluride (MCT) detector in which the spectral output of the IR LED and the spectral response of the MCT detector is centered on the spectral absorbance of an ester bond, a defining spectral characteristic of FAME. Other IR LEDs with differing spectral outputs can be used to measure the presence and/or concentration of different analytes in different fluids.

In accordance with an embodiment, a gas sensor includes a substrate having a cavity for providing an optical interaction path; a thermal emitter configured to emit broadband IR radiation; a wavelength selective structure configured to filter the broadband IR radiation emitted by the thermal emitter; and an IR detector configured to provide a detector output signal based on a strength of the filtered IR radiation having traversed the optical interaction path.

This disclosure provides a highly accurate NDIR gas sensor and a highly accurate optical device even using a simplified optical filter. The NDIR gas sensor and the optical device include: an optical filter having a substrate and a multilayer film on the substrate; and an infrared light emitting and receiving device; where the multilayer film has a structure in which a first layer and a second layer are alternately stacked; the active layer contains Al.sub.xIn.sub.1-xSb or InAs.sub.ySb.sub.1-y; and the optical filter includes a wavelength range having an average transmittance of 70% or more with a width of 50 nm or more in 2400-6000 nm, and has a maximum transmittance of 5% or more in 6000-8000 nm and an average transmittance of 2% or more and 60% or less in 6000-8000 nm.

Presently disclosed is a lighting system and methods of using the lighting system for in vitro potency assay for photofrin. The lighting system includes a lamp housing, a first lens, an infrared absorbing filter, an optical filter, and a second lens. The lamp housing includes a lamp and a light-port. In operation, broad spectrum light from the lamp exits the lamp housing by passing through the light-port. The first lens then collimates the broad spectrum light that exits the lamp housing through the light-port. The infrared absorbing filter then passes a first portion of the collimated broad spectrum light to the optical filter and absorbs infrared light of the broad spectrum light. The optical filter then passes a second portion of the collimated broad spectrum light to the second lens. The second lens then disperses the second portion of the collimated light to provide uniform irradiation of a cell culture plate. A method of using the lighting system for studying a photosensitizer is also disclosed.