One variation of a method for detecting a fire includes: during a first time period: detecting an increase in ambient light intensity and detecting an increase in ambient humidity; responsive to the increase in ambient light intensity and the increase in ambient humidity, detecting a fire event; during a second time period: correlating a decrease in ambient light intensity with an increase in visual obscuration; detecting an increase in ambient air temperature; in response to a magnitude of the increase in visual obscuration remaining below a high obscuration threshold and a magnitude of the increase in ambient temperature remaining below a high temperature threshold, classifying the fire as an incipient fire; and, in response to the magnitude of the increase in visual obscuration exceeding the high obscuration threshold and the magnitude of the increase in ambient temperature exceeding the high temperature threshold, classifying the fire as a developed fire.

Embodiments of the present disclosure relate to a flame detector. The flame detector comprises a light guide system including a first end and a second end opposite to the first end, a light path being formed between the first end and the second end and extending along an optical axis; a first hole disposed at the first end, extending along the optical axis and forming a part of the light path, the first hole being configured to receive light emitted by a flame to be detected; and a second hole disposed at the second end, extending along the optical axis and forming a part of the light path, sizes of the first and second holes and a length of the light path being configured such that a detection angle of the light guide system is between 0.5 degrees and 3 degrees.

This relates to sensor systems, detectors, imagers, and readout integrated circuits (ROICs) configured to selectively detect one or more frequencies or polarizations of light, capable of operating with a wide dynamic range, or any combination thereof. In some examples, the detector can include one or more light absorbers; the patterns and/or properties of a light absorber can be configured based on the desired measurement wavelength range and/or polarization direction. In some examples, the detector can comprise a plurality of at least partially overlapping light absorbers for enhanced dynamic range detection. In some examples, the detector can be capable of electrostatic tuning for one or more flux levels by varying the response time or sensitivity to account for various flux levels. In some examples, the ROIC can be capable of dynamically adjusting at least one of the frame rate integrating capacitance, and power of the illumination source.

A first radiance meter is directed toward an object to be measured, radiance is measured through a space where dust is present with the use of at least two wavelengths by the first radiance meter, second radiance meters which are equal in number to one or more objects having temperatures different from that of the object to be measured are directed toward the objects, radiances are measured through the space with the use of at least two wavelengths by the second radiance meters respectively, and a temperature of the object to be measured, a temperature of the dust, and concentration of the dust are measured from the radiances measured by the first radiance meter and the second radiance meters.

A temperature sensor includes a first infrared measuring means, a second infrared measuring means, and a calculating unit. The first infrared measuring means measures infrared rays emitted from an object and outputs a first voltage. The second infrared measuring means measures infrared rays emitted from around the object and outputs a second voltage. The calculating unit calculates the output temperature of the object from the first voltage, calculates the ambient temperature of the object from the second voltage, and corrects the output temperature based on the ambient temperature to calculate the temperature of the object.

A method and device for user authorization is presented herein. The authorization device may be integrated in a display interface configured to receive an infrared input signal. The device may include a means for converting the infrared signal into an electric signal. The device may further include a processor configured to analyze the electrical signal. The processor may further be configured to provide an authorization of a user based on the analysis of the electrical signal.

Methods and apparatus for monitoring a temperature of an object over time using a thermal imaging camera. The methods and apparatus may gather infrared temperature data from a selected source of temperature data within a scene at a selected time interval and display a graphical plot of the gathered temperature data on a digital display.

The present invention relates to a method for detecting the presence of gas hydrates and/or ice in a medium. The method comprises at least the following steps:

measuring at least at one measurement point in said medium two characteristic values of Raman spectra corresponding to two distinct vibration modes of the OH bonds of water, and determining the ratio of said two characteristic values,

determining the temperature T in said medium at said measurement point of said spectra,

comparing ratio with a value T.sub.0 corresponding to a predetermined threshold of formation of said crystals for said temperature T, and

determining the presence or not of hydrate and/or ice crystals from said comparison.

The present specification generally relates to the field of imaging device and particularly discloses an imaging device for detecting infrared radiation. The imaging device comprises a first set of detectors responsive to infrared electromagnetic radiation in a first wavelength band, a second set of detectors and a filter disposed above the second set of detectors to prevent registration of electromagnetic radiation outside a second wavelength band at the second set of detectors. The second wavelength band is a subset of the first wavelength band. The imaging device is configured to detect a deviation from an expected value of a level of electromagnetic radiation in a third wavelength band based on signals obtained from the first set of detectors and the second set of detectors. The third wavelength band is within the first wavelength band and outside the second wavelength band.

According to one embodiment of the present disclosure, there is provided an ultraviolet detector, including: an ultraviolet ray transmitting part configured to transmit ultraviolet ray contained in incident light; a wavelength conversion part configured to convert the ultraviolet ray transmitted through the ultraviolet ray transmitting part into visible light; and a visible light receiving part configured to detect the visible light obtained by the wavelength conversion part.