• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.336-341
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• 2013

In this paper, the design concept of a low-temperature vacuum blackbody was described, and thermophysical model of the blackbody was numerically evaluated. Also the working performance of low-temperature vacuum blackbody was evaluated using infrared camera system. The blackbody system was constructed to operate under high-vacuum conditions ($2.67{\times}10^{-2}$ Pa) to reduce temperature uncertainty, which is caused by vapor condensation at low temperatures usually below 273 K. In addition, both heat sink and heat shield including cold shield were installed around radiator to prevent heat loss from the blackbody. Simplified mathematical model of blackbody radiator was analyzed using modified Stefan-Boltzmann's rule. The infrared radiant performance of the blackbody was evaluated using infrared camera. Based on the results of measurements, and simulation, temperature stability of the low-temperature vacuum blackbody demonstrated that the blackbody system can serve as a highly stable reference source for the calibration of an infrared optical system.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.335-339
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• 2018

The optical characteristics of a terahertz (THz) antenna-coupled bolometer (ACB) detector were evaluated using a pulsed quantum cascade laser (QCL) and radiation blackbody sources. We investigated a method for measuring the responsivity and noise-equivalent power (NEP) of the THz detector using two different types of light sources. When using a QCL source with a frequency of 3 THz, the average responsivity of 24 devices was $1.44{\times}10^3V/W$ and the average NEP of those devices was $3.33{\times}10^{-9}W/{\surd}Hz$. The average responsivity and NEP as measured by blackbody source were $1.79{\times}10^5V/W$ and $6.51{\times}10^{-11}W/{\surd}Hz$, respectively, with the measured values varying depending on the light source. This was because the output power of each light source was different, with the laser source being driven by a pulse type wave and the blackbody source being driven by a continuous wave. The power input to the THz sensor was also different. Futhermore, the responsivity and NEP values measured using band pass filter (BPF) were similar to those measured when using only THz windows. It was found that ACB sensor responds normally in the THz region to both the laser and the blackbody source, and the method was confirmed to effectively evaluate the characteristics of the THz sensor.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.400-407
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• 2008

An Instrument to measure normal spectral emissivity is built using a Fourier Transform-Infrared (FT-IR) spectrometer. The instrument is composed of four main parts, reference blackbody, sample furnace, optics system, and FT-IR spectrometer. Measurement ranges of temperature and wavelength are $200^{\circ}C{\sim}500^{\circ}C$ and $3.5{\mu}m{\sim}20{\mu}m$, respectively. Measured emissivity of the reference blackbody is greater than 0.9993 with combined relative uncertainty less than 0.69%, which can be considered an ideal blackbody. We studied the emissivity of opaque alumina, graphite, anodized aluminum, and steel (IMS 200). It is shown that emissivity increases with the roughness of the steel (IMS 200) surface.

• Atmosphere
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• v.22 no.4
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• pp.473-481
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• 2012

The objective methods estimating the radius of maximum wind (RMW) of tropical cyclones (TCs) are discussed using infraed (IR) imagery of geostationary satellite, and an alternative method is suggested that can estimate RMW in the TCs having eyes using IR imagery. The RMW-estimating methods are based on the characteristic structure of the eyewall of a tropical cyclone. RMW is dependent upon the radius of the eye and the distance from the center to the top of the most developed convective cloud. In order to test these methods, blackbody brightness temperature of Korean geostationary satellite, COMS (Communication, Ocean, and Meteorological Satellite) IR imagery are utilized in this study. The estimated RMWs are compared with surface winds of ASCAT (Advanced Scatterometer) of a polar orbiting satellite.

• Bulletin of the Korean Space Science Society
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• 1995.10a
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• pp.34-34
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• 1995

No Abstract, See Full Text

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.10
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• pp.952-958
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• 2011

On-board IR calibration device has been developed for calibration of spaceborne image sensor. It is composed of a blackbody to provide two different radiance temperatures, tilt mirror with a function of stow and deploy to view the blackbody during the calibration and on-board calibration control unit to control the function of the blackbody and tilt mirror. In this paper, to guarantee the structural safety of the unit, the structural and thermal analysis including a thermo-elastic analysis for verifying structural safety on the soldered part of chips have been performed. In addition, safety margin of the chips on the PCB obtained from the conventional analytical method has been compared to the results from the FEM analysis.

• Korean Journal of Optics and Photonics
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• v.21 no.4
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• pp.133-138
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• 2010

All radiation thermometers have a size-of-source effect (SSE) and a self-radiation effect (SRE). The SSE,defined as dependence of the detector signal of a radiation thermometer on the diameter of a source, is critically dependent on the wavelength since diffraction is the main cause. In this paper, we have measured the SSE and the SRE of TRT2 (Transfer Radiation Thermometer 2, HEITRONICS) widely used as a transfer standard in low and middle temperature range. At $300^{\circ}C$, The radiation temperature difference between the 60 mm diameter blackbody and 10 mm diameter blackbody due to the SSE was estimated to be $3.5^{\circ}C$ in low temperature mode ($8-14\;{\mu}m$) and $0.5^{\circ}C$ in middle temperature mode ($3.9\;{\mu}m$). In addition, the measured radiation temperature difference of the blackbody due to the SRE was found to be 110 mK when the body temperature change of TRT2 was set at $2.6^{\circ}C$.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.9
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• pp.32-36
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.455-456
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• 2006

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.389-394
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• 2006

Fragmentation efficiencies of various ‘activated-ion’ electron capture dissociation (AI-ECD) methods are compared for a model system of bovine ubiquitin 7+ cations. In AI-ECD studies, sufficient internal energy was given to protein cations prior to ECD application using IR laser radiation, collisions, blackbody radiation, or in-beam collisions, in turn. The added energy was utilized in increasing the population of the precursor ions with less intra-molecular noncovalent bonds or enhancing thermal fluctuations of the protein cations. Removal of noncovalent bonds resulted in extended structures, which are ECD friendly. Under their best conditions, a variety of activation methods showed a similar effectiveness in ECD fragmentation. In terms of the number of fragmented inter-residue bonds, IR laser/blackbody infrared radiation and ‘in-beam’ activation were almost equally efficient with ~70% sequence coverage, while collisions were less productive. In particular, ‘in-beam’ activation showed an excellent effectiveness in characterizing a pre-fractionated single kind of protein species. However, its inherent procedure did not allow for isolation of the protein cations of interest.