共查询到20条相似文献,搜索用时 15 毫秒
1.
红外耳温计分度方法及数据分析 总被引:1,自引:1,他引:0
研制了一种专门用于红外耳温计分度的双孔黑体空腔,并用研制的黑体空腔对红外耳温计在37℃和41℃进行了分度实验.实验结果表明,此黑体空腔的空腔发射率已达到0.999,完全能作为红外耳温计分度的标准辐射源.最后对实验结果进行了不确定度的评定. 相似文献
2.
C. Monte B. Gutschwager S. P. Morozova J. Hollandt 《International Journal of Thermophysics》2009,30(1):203-219
A new experimental facility was realized at the PTB for reduced-background radiation thermometry under vacuum. This facility
serves three purposes: (i) providing traceable calibration of space-based infrared remote-sensing experiments in terms of
radiation temperature from −173 °C to 430 °C and spectral radiance; (ii) meeting the demand of industry to perform radiation
thermometric measurements under vacuum conditions; and (iii) performing spectral emissivity measurements in the range from
0 °C to 430 °C without atmospheric interferences. The general concept of the reduced background calibration facility is to
connect a source chamber with a detector chamber via a liquid nitrogen-cooled beamline. Translation and alignment units in
the source and detector chambers enable the facility to compare and calibrate different sources and detectors under vacuum.
In addition to the source chamber, a liquid nitrogen-cooled reference blackbody and an indium fixed-point blackbody radiator
are connected to the cooled beamline on the radiation side. The radiation from the various sources is measured with a vacuum
infrared standard radiation thermometer (VIRST) and is also imaged on a vacuum Fourier-transform infrared spectrometer (FTIR)
to allow for spectrally resolved measurements of blackbodies and emissivity samples. Determination of the directional spectral
emissivity will be performed in the temperature range from 0 °C to 430 °C for angles from 0° to ±70° with respect to normal
incidence in the wavelength range from 1 μm to 1,000 μm.
References to commercial products are provided for identification purposes only and constitute neither endorsement nor representation
that the item identified is the best available for the stated purpose. 相似文献
3.
黑体辐射源的多波长有效亮度温度校准和不同溯源方式特点分析 总被引:1,自引:0,他引:1
介绍了中国计量科学研究院建立的标准变温黑体辐射源和有效亮度温度比较装置;阐述了黑体辐射源多波长有效亮度温度校准的2种方法,给出典型校准结果并分析了辐射源特性。比较分析了3种溯源方式的性能特点及其应用的影响因素。提出控温复现性的概念,它是以往未被重视的辐射源关键性能参数。多波长有效亮度温度校准是可减小或消除有效发射率和接触测温测点温差影响的溯源方案,与传统溯源方式特性互补,可用于评价辐射源的有效发射率和测点温差,对控温复现性好的辐射源效果最优。 相似文献
4.
在辐射温度计检定中,根据规程要求,需要将辐射温度计的发射率设置为1,而在实际校准辐射温度计的过程中发现大量发射率固定且不为1的情况,同样有用户要求校准后给出不同发射率下的辐射温度计修正值,为实现宽波段任意固定发射率辐射温度计在校准过程中的修正值计算,文章使用LabVIEW的两分法迭代实现Plank公式的积分算法,有效提高校准过程的自动化程度,文章用实例说明了两分法与普通步进算法的效率区别,从而高效的实现了任意波段、任意发射率、任意温度点的温度修正值计算。 相似文献
5.
Over the temperature range from 156 to 962°C, the NPL maintains a series of heatpipe blackbody sources for the calibration
of customer sources, radiation thermometers, and thermal imagers. The temperature of each of the sources is determined using
a calibrated platinum resistance thermometer or gold-platinum thermocouple placed close to the radiating surface at the back
of the cavity. The integrity of such a blackbody source relies on it having good temperature uniformity, a high and well-known
effective emissivity, and having the sensor in good thermal contact with the cavity. To verify the performance of the blackbody
sources, it is necessary to use an infrared thermometer that has been independently calibrated to compare the radiance temperature
of the source with the temperature measured by the contact sensor. Such verification of the NPL blackbodies has been carried
out at short wavelengths: from 500 to 1,000°C using the NPL LP2 calibrated using the NPL gold point, and at 1.6 μm using an
InGaAs-based radiation thermometer calibrated at a series of fixed-points from indium (156°C) to silver (962°C). Thermal imaging
systems traditionally operate over the 3–5 μm waveband and are calibrated using NPL sources. Up until now, it has not been
possible to verify the performance of the sources in this waveband except indirectly by cross-comparison of the sources where
they overlap in temperature. A mid-infrared (nominally 3–5 μm) radiation thermometer has, therefore, been designed, constructed,
and validated at NPL. The instrument was validated and calibrated using the fixed-point blackbody sources and then used to
validate the heatpipe blackbodies over their temperature range of operation. The results of the instrument validation and
blackbody measurements are given. 相似文献
6.
Sønnik Clausen 《International Journal of Thermophysics》2007,28(6):2145-2154
The normal spectral emissivity of commercial infrared calibrators is compared with measurements of anodized aluminum samples
and grooved aluminum surfaces coated with Pyromark. Measurements performed by FTIR spectroscopy in the wavelength interval
from 2 to 20 μm and at temperatures between 5 and 550°C are presented with absolute uncertainties from 0.25% to 1% in spectral
regions with sufficient signal and no significant atmospheric gas absorption. A large variation in emissivity with wavelength
is observed for some surfaces, i.e., from 1% to 3% to more than 10%. The variation in emissivity using similar materials can
be reduced to 0.5–1% by optimizing the coating process and the surface geometry. Results are discussed and an equation for
calculation of the equivalent blackbody surface temperature from FTIR spectra is presented, including reflected ambient radiation.
It is in most cases necessary to correct temperature calibration results for calibrators calibrated at 8–14 μm to obtain absolute
accuracies of 0.1–1°C in other spectral regions depending on the temperature. Uncertainties are discussed and equations are
given for the correction of measured radiation temperatures. 相似文献
7.
大口径高发射率面型黑体辐射源的研制 总被引:1,自引:0,他引:1
黑体辐射源作为定标标准器,在红外测量设备的辐射定标中具有重要作用。为应对大口径红外测量设备的辐射定标工作需求,设计了1台辐射面积为400mm×400mm的面型黑体辐射源。采用多路控温和连接固定冷源的方式对黑体进行温度控制;通过热仿真确定合适的传热模型,同时结合高发射率涂层工艺与辐射面的结构设计使黑体具备高发射率,辐射面有效发射率可达到0.992;在真空环境下,利用标准铂电阻温度计测量得到黑体辐射面源的温度均匀性偏差最大为0.101K,稳定性平均值为0.018K/10min,该黑体辐射光源能够满足现阶段大口径红外测量设备的使用需求。 相似文献
8.
The National Metrology Institute of Spain (CEM) has designed, characterized, and set-up its new system to calibrate thermocouples and infrared radiation thermometers up to 1600 °C by comparison to radiation thermometry. This system is based on a MoSi2 three-zone furnace with a graphite blackbody comparator. Two interchangeable alumina tubes with different structures are used for thermocouples and radiation thermometer calibrations. The reference temperature of the calibration is determined by a standard radiation thermometer. Normally, this is used at CEM to disseminate the International Temperature Scale of 1990 (ITS-90) in the radiation range, and it refers to the Cu fixed point. Several noble metal thermocouples and infrared radiation thermometers with a central wavelength near 900 nm have been calibrated, and their uncertainty budgets have been obtained. 相似文献
9.
P. Saunders J. Fischer M. Sadli M. Battuello C. W. Park Z. Yuan H. Yoon W. Li E. van der Ham F. Sakuma J. Ishii M. Ballico G. Machin N. Fox J. Hollandt M. Matveyev P. Bloembergen S. Ugur 《International Journal of Thermophysics》2008,29(3):1066-1083
Below the freezing point of silver, radiation thermometers are generally calibrated by implementing the multi-point interpolation
method using blackbody measurements at three or more calibration points, rather than the ITS-90 extrapolation technique. The
interpolation method eliminates the need to measure the spectral responsivity and provides greater accuracy at the longer
wavelengths required below the silver point. This article identifies all the sources of uncertainty associated with the interpolation
method, in particular, those related to the reference blackbody temperatures (either variable-temperature or fixed-point blackbodies)
and to the measured thermometer signals at these points. Estimates are given of the ‘normal’ and ‘best’ uncertainties currently
achievable. A model of the thermometer response is used to propagate all the uncertainties at the reference points and provide
a total uncertainty at any temperature within the calibration range. The multi-point method has the effect of constraining
the total uncertainty over this range, unlike the ITS-90 technique for which the uncertainties propagate as T
2. This article is a joint effort of the working group on radiation thermometry of the Consultative Committee for Thermometry
(CCT), summarizing the knowledge and experience of all experts in this field. 相似文献
10.
11.
Chul-Woung Park Yong Shim Yoo Bong-Hak Kim Sejong Chun Seung-Nam Park 《International Journal of Thermophysics》2011,32(7-8):1622-1632
A large aperture blackbody (LABB) with a diameter of 1 m has been successfully constructed for calibrating radiation thermometers and infrared radiometers with a wide field of view in the temperature range between 10 °C and 90 °C. The blackbody is a 1 m long cylindro-conical cavity with a diameter of 1.1 m. Its conical bottom has an apex angle of 120°. To achieve good temperature stability and uniformity, the cavity is integrated to a water-bath to which the pressurized water is supplied from a reservoir. To reduce the convection heat loss from the cavity to the ambient, the cavity is purged of the dried air that passes through a coiled tube immersed in the reservoir. For an uncertainty evaluation of the LABB, its temperature stability was measured by using a reference radiation thermometer (RRT) and a platinum resistance thermometer (PRT), and its radiance temperature distributions on the aperture plane were measured by using a thermal camera. Measuring the spectral emissivity of the coating material, the effective emissivity of the blackbody was calculated to be 0.9955 from 1 ??m to 15 ??m. The expanded uncertainty of the radiance temperature scale was evaluated based on the PRT readings, which vary from 0.3 °C to 0.5 °C (k = 2) in the temperature range. The temperature scale is validated by comparing with the RRT of which the temperature scale is realized by a multiple fixed-point calibration. 相似文献
12.
H. C. McEvoy M. J. Martin A. Steiner E. Schreiber F. Girard M. Battuello M. Sadli P. Ridoux B. Gutschwager J. Hollandt A. Diril Ö. Pehlivan 《International Journal of Thermophysics》2014,35(3-4):446-466
Over the medium temperature range (from \(156\,^{\circ }\mathrm{C}\) to \(1000\,^{\circ }\mathrm{C}\) ), radiation thermometry is usually established within a national metrology institute (NMI) by means of variable temperature blackbody radiation sources, whose temperature is determined using a platinum resistance thermometer or thermocouple, calibrated in terms of the International Temperature Scale of 1990 (ITS-90), positioned in close proximity to the back radiating surface of the blackbody. It is also reasonably common to establish a scale using a suitable radiation thermometer, such as an indium gallium arsenide (InGaAs) detector-based narrow band radiation thermometer, calibrated using a number of fixed-point blackbody sources from the indium (In) to silver (Ag) (or copper (Cu)) points, with the calibration results fitted using a parameterized Planckian interpolation function. During 2007 and 2008, two InGaAs-based radiation thermometers were circulated around seven NMIs within the European Association of National Metrology Institutes (EURAMET) region in order to undertake a comparison of parameters necessary for radiation thermometry over the medium temperature range. Measurements were made of the size-of-source effect and gain (range) ratios of the two thermometers along with an assessment of the effect of changes in the ambient temperature and humidity on the thermometer output. The thermometers were also calibrated using fixed-point and/or variable temperature blackbody sources at each institute. A brief overview of the results obtained by this project is presented in this paper. 相似文献
13.
A comparison of a Pt/Pd calibration above the Ag point between the INRIM and NMC was arranged with the aims of evaluating measurement systems and exploiting the potential of the Pt/Pd thermocouples. Two commercial Pt/Pd thermocouples were used as transfer thermometers. A calibration method using a blackbody cavity as a transfer source and a radiation thermometer as a reference thermometer was adopted in both institutes. The T 90 carried by the radiation thermometers is established by an extrapolation technique for INRIM and by scale realization according to ITS-90 definition for NMC and, therefore, this exercise is also a useful comparison of different approaches to disseminate T 90 above the Ag point. The comparison results are presented and analyzed. 相似文献
14.
B. Gutschwager J. Hollandt T. Jankowski R. Gärtner 《International Journal of Thermophysics》2008,29(1):330-340
A thermal infrared radiation thermometer was jointly developed by the Physikalisch-Technische Bundesanstalt and Raytek GmbH
for temperature measurements from − 150°C to 170°C under vacuum. The radiation thermometer is a purpose-built instrument to
be operated with the PTB reduced-background infrared calibration facility. The instrument is a stand-alone system with an
airtight housing that allows operation inside a vacuum chamber, attached to a vacuum chamber, and in air. The radiation thermometer
will serve to calibrate thermal radiation sources, i.e., blackbody radiators, by comparing their radiance temperature to that
of a variable-temperature reference blackbody inside the reduced-background calibration facility. Furthermore, since it can
be operated under vacuum and in air, the instrument also allows the water- and ammonia-heat-pipe reference blackbodies of
the PTB low-temperature calibration facility operated in air to be compared with the variable-temperature blackbody operated
under vacuum. Finally, provided that sufficient long-term stability is achieved, the instrument shall be used as a transfer
radiation thermometer to carry and compare the temperature scale of PTB by means of radiation thermometry to remote-sensing
calibration facilities outside PTB. The mechanical, optical, and electrical designs of the instrument are reported. Results
of investigations on the temperature resolution, size-of-source effect, and the reference function are given. The heat-pipe
blackbodies operating in air are compared to the variable-temperature blackbody operated under vacuum by using the vacuum
radiation thermometer.
References to commercial products are provided for identification purposes only and constitute neither endorsement nor representation
that the item identified is the best available for the stated purpose. 相似文献
15.
提出了一种检定红外温度计的新方法。应用此方法 ,检定温度计是直接对准被测对象而不是黑体。此外 ,它回避了光谱发射率的测量和温度计光谱响应度的数据。 相似文献
16.
S. N. Mekhontsev V. B. Khromchenko L. M. Hanssen 《International Journal of Thermophysics》2008,29(3):1026-1040
The realization and the dissemination of spectral radiance and radiance temperature scales in the temperature range of −50
to 250°C and spectral range of 3–13 μm at the National Institute of Standards and Technology are described. The scale is source-based
and is established using a suite of blackbody radiation sources, the emissivity and temperature of which have been thoroughly
investigated. The blackbody emissivity was measured using the complementary approaches of modeling, reflectometry, and the
intercomparison of the spectral radiance of sources with different cavity geometries and coatings. Temperature measurements
are based on platinum resistance thermometers and on the direct use of the phase transitions of pure metals. Secondary sources
are calibrated using reference blackbody sources, a spectral comparator, a controlled-background plate, and a motion control
system. Included experimental data on the performance of transfer standard blackbodies indicate the need for development of
a recommended practice for their specification and evaluation. Introduced services help to establish a nationwide uniformity
in metrology of near-ambient thermal emission sources, providing traceability in spatially and spectrally resolved radiance
temperature, spectral radiance, and background-corrected effective emissivity. 相似文献
17.
18.
19.
Hsin-Yi Ko Bor-Jiunn Wen Shu-Fei Tsa Guo-Wei Li 《International Journal of Thermophysics》2009,30(1):98-104
A newly designed high-emissivity cylindrical blackbody source with a large diameter aperture (54 mm), an internal triangular-grooved
surface, and concentric grooves on the bottom surface was immersed in a temperature-controlled, stirred-liquid bath. The stirred-liquid
bath can be stabilized to better than 0.05°C at temperatures between 30 °C and 70 °C, with traceability to the ITS-90 through
a platinum resistance thermometer (PRT) calibrated at the fixed points of indium, gallium, and the water triple point. The
temperature uniformity of the blackbody from the bottom to the front of the cavity is better than 0.05 % of the operating
temperature (in °C). The heat loss of the cavity is less than 0.03 % of the operating temperature as determined with a radiation
thermometer by removing an insulating lid without the gas purge operating. Optical ray tracing with a Monte Carlo method (STEEP
3) indicated that the effective emissivity of this blackbody cavity is very close to unity. The size-of-source effect (SSE)
of the radiation thermometer and the effective emissivity of the blackbody were considered in evaluating the uncertainty of
the blackbody. The blackbody uncertainty budget and performance are described in this paper. 相似文献
20.
Recent improvements in the fabrication of short-wave infrared (SW-IR) quantum detectors have opened a new era in radiation
thermometry. Ambient and higher temperatures can be measured with low uncertainties using thermoelectrically (TE) cooled extended-InGaAs
(E-IGA) and short-wave photovoltaic-HgCdTe (SW-MCT) detectors. Since these detectors have low cut-off wavelengths (2.5 μm
and 2.8 μm, respectively), they do not respond past cut-off and are less sensitive to the background infrared radiation, resulting
in orders of magnitude lower background noise than traditional broad-band infrared detectors such as cryogenically cooled
quantum detectors or thermal detectors. At the same time, the cut-off is far enough in the infrared to obtain a large enough
signal from the source of interest. Because of the low detector cut-off wavelength, traditional glass-based optics can be
used in the radiation thermometers. A chopper-produced alternating-current (AC) signal was used to measure low temperatures
by separating the AC signal from the background-radiation-produced direct-current (DC) signal and its fluctuations. Design
considerations and characteristics of a newly developed SW-IR radiation thermometer are discussed. A noise-equivalent temperature
difference (NETD) of < 3mK for a 50°C blackbody was measured. At the human body temperature of 36°C, the obtained NETD of
~10mK indicates that these detectors can be used in non-contact temperature measurements to replace thermopile- or pyroelectric-based
radiation thermometers. 相似文献