An additive manufacturing apparatus includes a laser and a detection system. The laser emits a laser beam to heat a powder bed to form a melt pool, and the melt pool emits light proportional to a temperature of the melt pool. The detection system includes a spectral disperser and one of a) two or more on-axis sensors or b) a line scanner. The two or more on-axis sensors or the line scanner are/is located along an axis of the emitted light, the detection system receives the emitted light from the melt pool, and an intensity of the emitted light detected by the a) two or more on-axis sensors or the b) line scanner is compared with a blackbody spectral map at a particular wavelength of the emitted light to determine a temperature of the melt pool.

An object of the present invention is to provide a radiation temperature measuring device capable of preventing reduction in the accuracy of temperature measurement due to an electromagnetic wave reflected by a measurement target. A radiation temperature measuring device includes a reflective polarizing plate configured to reflect a polarized wave of one direction in an electromagnetic wave radiated from an object to be measured and transmit or absorb a polarized wave of a direction perpendicular to the one direction and an infrared sensor configured to detect the polarized electromagnetic wave of the one direction reflected by the reflective polarizing plate.

A temperature sensing system for a resistive welding process for a tube performs repeatable temperature measurement using a camera to detect multiple distinct visible light wavelengths even as the ambient environment in the view path changes. Sensed colors in a field of view in the vicinity of a weld are output to a computing element that calculates a corresponding temperature and alerts an operator when the sensed color exceeds a preset color range.

Techniques are provided for an image processing device to receive image information comprising image data for a plurality of mid-wave infrared region (MWIR) channels, where the image data is obtained during a first imaging period and during a second imaging period temporally different from the first imaging period. A plurality of sets of atmospheric wind vectors are calculated using differences between image data obtained during the first imaging period and the image data obtained during the second imaging period for corresponding sets of MWIR channels. An altitude is assigned to the plurality of atmospheric wind vectors in each set based on a brightness temperature of each wind vector and a pre-computed atmospheric temperature profile to generate a set of two-dimensional wind fields comprising one two-dimensional wind field for each set of MWIR channels.

Various embodiments disclosed herein describe an infrared (IR) imaging system for detecting a gas. The imaging system can include an optical filter that selectively passes light having a wavelength in a range of 1585 nm to 1595 nm while attenuating light at wavelengths above 1600 nm and below 1580 nm. The system can include an optical detector array sensitive to light having a wavelength of 1590 that is positioned rear of the optical filter.

Various embodiments disclosed herein describe an infrared (IR) imaging system for detecting a gas. The imaging system can include an optical filter that selectively passes light having a wavelength in a range of 1585 nm to 1595 nm while attenuating light at wavelengths above 1600 nm and below 1580 nm. The system can include an optical detector array sensitive to light having a wavelength of 1590 that is positioned rear of the optical filter.

A background subtracted spectrometer for airborne infrared radiometry. The background subtracted spectrometer may comprise: a filter array, a detector, and a dewar containing liquid nitrogen. The filter array may be configured to selectively pass different spectral bands of infrared radiation. The filter array may comprise: at least one linear variable filter and a plurality of bandpass filters. The detector may comprise a focal plane array configured to receive the different spectral bands of infrared radiation simultaneously transmitted through the filter array. The detector may generate one or more electrical signals indicative of infrared radiation intensity as a function of wavelength. The filter array may be coupled to the focal plane array of the detector, and the filter array and detector may be conductively cooled by the liquid nitrogen to improve signal-to-noise ratio and spectral measurements. The background subtracted spectrometer preferably lacks a circular variable filter and relay lens.

Various embodiments disclosed herein describe an infrared (IR) imaging system for detecting a gas. The imaging system can include an optical filter that selectively passes light having a wavelength in a range of 1585 nm to 1595 nm while attenuating light at wavelengths above 1600 nm and below 1580 nm. The system can include an optical detector array sensitive to light having a wavelength of 1590 that is positioned rear of the optical filter.

A two-wavelength, single-camera imaging thermography system for in-situ temperature measurement of a target, comprising: a target light path inlet conduit for receiving a target light beam reflected from the target; a beam splitter installed in a splitter housing at a distal end of the target light path conduit, wherein the beam splitter divides the target light beam into a first light beam and a second light beam; a first light path conduit emanating from the splitter housing comprising a first aperture iris installed within the first light path conduit for aligning the first light beam; a first band pass filter installed within the first light path conduit for regulating the first light beam to a first wavelength 1 and an optional half waveplate installed within the first light path conduit to modulate a polarization ratio of the first light beam of 1 wavelength; a second light path conduit emanating from the splitter housing comprising a second aperture iris installed within the second light path conduit for aligning the second light beam; a second band pass filter installed within the second light path conduit for regulating the second light beam to a second wavelength 2; a junction housing, wherein distal ends of each of the first and second light path conduits are connected to the junction housing; a polarizing beam splitter installed in the junction housing, wherein the polarizing beam splitter reflects the first light beam of 1 wavelength along the same path or a parallel path of the second light beam of 2 wavelength that passes directly through the polarizing beam splitter unreflected to create a merged light beam comprising light of 1 and 2 wavelengths; and a light path outlet conduit connected to the junction for directing the merged beam to a high-speed camera for imaging.

A semiconductor gas imaging device system and method includes one chip dual band Type II Superlattice (T2SL) detectors comprising two back to back diodes wherein the bias is flipped. Embodiment voltages are +1V to 1V. For embodiments, only the detector with negative voltage detects incoming infrared radiation.