共查询到20条相似文献,搜索用时 15 毫秒
1.
T. Keawprasert K. Anhalt D. R. Taubert J. Hartmann 《International Journal of Thermophysics》2011,32(7-8):1697-1706
A monochromator integrating-sphere-based spectral comparator facility has been developed to calibrate standard radiation thermometers in terms of the absolute spectral radiance responsivity, traceable to the PTB cryogenic radiometer. The absolute responsivity calibration has been improved using a 75 W xenon lamp with a reflective mirror and imaging optics to a relative standard uncertainty at the peak wavelength of approximately 0.17 % (k = 1). Via a relative measurement of the out-of-band responsivity, the spectral responsivity of radiation thermometers can be fully characterized. To verify the calibration accuracy, the absolutely calibrated radiation thermometer is used to measure Au and Cu freezing-point temperatures and then to compare the obtained results with the values obtained by absolute methods, resulting in T ? T 90 values of +52 mK and ?50 mK for the gold and copper fixed points, respectively. 相似文献
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R. Winkler E. R. Woolliams W. S. Hartree S. G. R. Salim N. P. Fox J. R. Mountford Malcolm White S. R. Montgomery 《International Journal of Thermophysics》2007,28(6):2087-2097
For accurate determinations of thermodynamic temperature, NPL has developed its absolute radiation thermometer (ART), which
is calibrated traceably against a cryogenic radiometer. This article reviews some of the potential sources of systematic uncertainty
present in the calibration and use of ART. In particular, this article is concerned with the evaluation of the size-of-source
effect and the lens transmittance, as well as potential differences in the responsivity of a transfer trap detector when calibrated
in terms of radiant power and used in irradiance mode. 相似文献
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本文对检定辐射温度计所使用的标准器和检定装置的技术条件做了归纳和比较。详细介绍了检定前的准备工作、检定项目和检定步骤,总结了检定固有误差的方法和数据处理。 相似文献
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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
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现行的辐射温度计检定规程,概念不够清晰,具体操作步骤描述过于简单,造成检定的实际测量条件有明显的差异,由此导致检定结果的差异。本文从技术角度出发,提出了一种可行的操作方法,力图提高辐射温度计检定结果的准确度。 相似文献
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M. J. Martín J. M. Mantilla D. del Campo M. L. Hernanz A. Pons J. Campos 《International Journal of Thermophysics》2017,38(9):138
The evolving mise en pratique for the definition of the kelvin (MeP-K) [1, 2] will, in its forthcoming edition, encourage the realization and dissemination of the thermodynamic temperature either directly (primary thermometry) or indirectly (relative primary thermometry) via fixed points with assigned reference thermodynamic temperatures. In the last years, the Centro Español de Metrología (CEM), in collaboration with the Instituto de Óptica of Consejo Superior de Investigaciones Científicas (IO-CSIC), has developed several setups for absolute calibration of standard radiation thermometers using the radiance method to allow CEM the direct dissemination of the thermodynamic temperature and the assignment of the thermodynamic temperatures to several fixed points. Different calibration facilities based on a monochromator and/or a laser and an integrating sphere have been developed to calibrate CEM’s standard radiation thermometers (KE-LP2 and KE-LP4) and filter radiometer (FIRA2). This system is based on the one described in [3] placed in IO-CSIC. Different light sources have been tried and tested for measuring absolute spectral radiance responsivity: a Xe-Hg 500 W lamp, a supercontinuum laser NKT SuperK-EXR20 and a diode laser emitting at 6473 nm with a typical maximum power of 120 mW. Their advantages and disadvantages have been studied such as sensitivity to interferences generated by the laser inside the filter, flux stability generated by the radiant sources and so forth. This paper describes the setups used, the uncertainty budgets and the results obtained for the absolute temperatures of Cu, Co-C, Pt-C and Re-C fixed points, measured with the three thermometers with central wavelengths around 650 nm. 相似文献
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In the first half of 2005, Nederlands Meetinstituut Van Swinden Laboratorium B.V. (NMi VSL) redesigned their facilities for
radiation thermometry in a new laboratory building and an opportunity arose to implement new measurement methods. The new
facility is used for ITS-90 realization and dissemination in the temperature range from − 50 °C to 3,000 °C. A study was
performed to compare a silver-point realization with a fixed-point blackbody radiator (FP-BBR) to a sodium heat-pipe blackbody
radiator (HP-BBR) traceable via a HTSPRT to a contact thermometry silver point. It was found that the fixed-point realization
transfer to the sodium heat pipe results in an uncertainty from 0.2 K to 2.4 K for the ITS-90 over the temperature range from
961.78 °C to 3,000 °C. 相似文献
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热电偶温度计远程校准系统设计 总被引:1,自引:0,他引:1
计算机网络技术和虚拟仪器技术的发展为实现测量系统的远程控制提供了技术基础。本文介绍了利用LabVIEW控制数据采集模块,实现热电偶电动势信号的采集,并通过Internet实现数据的传输和接收,从而完成热电偶远程检定方案的实现。 相似文献
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Fumihiro Sakuma Laina Ma Tadashi Kobayashi 《International Journal of Thermophysics》2008,29(1):312-321
The first InGaAs radiation thermometer at NMIJ was developed more than ten years ago as a standard radiation thermometer operating
from 150 to 1,100°C. Its size-of-source effect (SSE) was as large as 1% from 6 mm in diameter to 50 mm in diameter. The new
thermometer has an SSE of 0.3%. The reason for the error in measuring the SSE of InGaAs thermometers was also found. The new
thermometer at first suffered from nonlinearity and the distance effect (DE). These deficiencies arose from the misalignment
of optics inside the thermometer and were solved by increasing the detector size from 1 mm in diameter to 2 mm in diameter.
Unfortunately, the detector of 2 mm diameter had a smaller S/N ratio than that of the 1 mm one at the indium (In) point. The
final design uses a detector of 1 mm diameter, but the radiation is focussed on a smaller area of the detector. The new thermometer
is smaller and lighter than preceding designs and other standard InGaAs radiation thermometers. The temperature of the main
part of the instrument, including the filter, the detector, and the preamplifier board, is controlled at 30°C. In addition
to the calibration with the six fixed points of copper (Cu), silver (Ag), aluminum (Al), zinc (Zn), tin (Sn), and indium (In),
the linearity from the In point to the Cu point, the SSE, the DE, and the spectral responsivity were measured. 相似文献
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K. Anhalt A. Zelenjuk D. R. Taubert T. Keawprasert J. Hartmann 《International Journal of Thermophysics》2009,30(1):192-202
The paper describes the new experimental setup assembled at the PTB for the absolute spectral responsivity measurement of
radiation thermometers. The concept of this setup is to measure the relative spectral responsivity of the radiation thermometer
using the conventional monochromator-based spectral comparator facility also used for the calibration of filter radiometers.
The absolute spectral responsivity is subsequently measured at one wavelength, supplied by the radiation of a diode laser,
using the new setup. The radiation of the diode laser is guided with an optical fiber into an integrating sphere source that
is equipped with an aperture of absolutely known area. The spectral radiance of this integrating sphere source is determined
via the spectral irradiance measured by a trap detector with an absolutely calibrated spectral responsivity traceable to the
primary detector standard of the PTB, the cryogenic radiometer. First results of the spectral responsivity calibration of
the radiation thermometer LP3 are presented, and a provisional uncertainty budget of the absolute spectral responsivity is
given. 相似文献
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用典型红外辐射温度计的辐射源尺寸效应的实验数据说明不同测量条件下的检定/校准结果的差异可能为其最大允许误差绝对值的数倍。提出具有明确测量条件的平面辐射源瞄准模型和以辐射源前置光阑的方式对于不同空腔黑体辐射源实现相同的等效平面源直径的方法,提出了对光阑的技术特性和放置距离要求,分析表明低温辐射源对光阑的冷却作用可能引起不可忽略的示值降低。采用等效平面源模型的实验结果表明以不同几何条件的空腔黑体辐射源可得到一致的检定结果。讨论了应用平面辐射源模型可能遇到的实际技术问题和解决的对策。 相似文献
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H. W. Yoon C. E. Gibson V. Khromchenko G. P. Eppeldauer 《International Journal of Thermophysics》2007,28(6):2076-2086
For measurements of radiance temperatures in the range from 150°C to 1,000°C, low uncertainties in the temperature measurements
can be achieved by using near-infrared InGaAs radiation thermometers. The design and construction of the NIST near-infrared
radiation thermometer (NIRT) that is optimized for low size-of-source effect (SSE) and noise-equivalent temperatures are described.
The NIRT utilizes a 50 mm diameter achromatic objective lens with low scatter that images a 4.5 mm diameter spot at a distance
of 50 cm from the objective in an on-axis design. A Lyot stop is implemented in the design with the aperture stop placed after
the field stop resulting in a collection f/12. A 3 mm diameter InGaAs detector is cooled to − 70°C using a four-stage thermoelectric
cooler to obtain high-shunt resistance for linear, low-noise operation at high transimpedance amplifier gains. For thermal
and structural stability, the optical components are placed on four, 15 mm diameter graphite-epoxy rods making the optical
throughput stable. Optical ray tracing with a commercial program is used to determine the Strehl ratio and other imaging parameters.
A possible approach for a detector-based temperature scale in this range which could result in 10 mK (k = 2) thermodynamic temperature uncertainties at the In-point is discussed. 相似文献
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To prevent short circuits, to improve stability, and to raise the upper temperature limit to the freezing point of copper (1084.62 °C), the high-temperature standard platinum resistance thermometer (HTSPRT) was redesigned. The most important change was an improvement in the structure of the sensor support. The strip support was replaced by a new specially designed cross support. The structure and design of the new HTSPRT are briefly described in this article. The test results of a group of thermometers are presented. The test included long-term drifts of the thermometers at the triple point of water and freezing point of silver during a period of a few hundred hours operation at 1085 °C, the short-term stability of R (tpw) and W (Ag) in a period of 5 days, and thermal cycles between 22 °C and 1085 °C. The test results show that the thermometer performance is improved, and the new HTSPRT can operate up to the freezing point of copper. 相似文献