共查询到18条相似文献，搜索用时 265 毫秒
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给出了在0～660．323℃温区标准铂电阻温度计(SPRT)的两个二次偏差函数：一个是由水三相点、锡凝固点和铝凝固点的检定值来确定;另一个由水三相点、锌凝固点和铝凝固点来确定。这两个二次偏差函数是ITS-90温标在0～660．323℃温区标准铂电阻温度计偏差函数的一个很好的近似。使用70支标准铂电阻温度计检验了这两个偏差函数,其误差一般不超过2．4mK,最大不超过4．7mK。 相似文献
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铂电阻温度计稳定性的研究 总被引：1，自引：0，他引：1
铂电阻温度计是ＩＴＳ -１９９０国际温标中规定的内插仪器 ,也是复现保存温标及温标传递的必要仪器。同时在对各类水银温度计、工业铂电阻温度计等温度传感器及仪表的检定时都是最常用的标准 ,所以铂电阻温度计的稳定与否是非常重要的。铂电阻温度计的稳定性与多种因素有关 ,如制作温度计使用的铂丝均匀性、纯度及工艺 ,温度计的制作过程工艺及退火 ,充气处理 ,新制温度计的退火处理 ,温度计的使用等。这里主要对各类温度计的退火及使用中稳定性的变化做一些分析研究。一、铂电阻温度计的稳定性国际上评定铂电阻温度计的稳定性 ,主要是看其… 相似文献
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本给出了0-30℃分温区内基于ITS-90温标定义的固定点——镓熔点复现装置的标准不确定及坟展不确定度评定,以及由此引起的0-30℃范围内工作基准铂电阻温度计分度的各温度点上的不确定度。本的分析结果可用于该温区内使用标准铂手工电阻温度计测温结果的不确定度分析。 相似文献
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A new comparison system has been constructed using a Gifford- McMahon type cryogenic refrigerator for the calibration of capsule-type
standard platinum resistance thermometers (CSPRTs) below 273.16 K at the National Metrology Institute of Japan (NMIJ). The
system can compare six CSPRTs at once. A gold-plated comparison block, in which CSPRTs are mounted for calibration, is made
from oxygen-free high-conductivity copper. The standard uncertainties related to the temperature control of the system are
estimated to be 0.04 mK. The calibrated values for CSPRTs and a rhodium–iron resistance thermometer obtained using the comparison
system are in good agreement with those obtained by the direct realization of the low-temperature fixed points of the ITS-90
within the combined standard uncertainty for the calibration using the comparison system. 相似文献
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按时规范,ＪＪＦ１０５９－１９９９,对二等标准铂电阻温度计在锌凝固点及水沸点检定的不确定度进行了评定,通过建立测量数学模型确定各标准各不确定度分量,并按不确定度传播公式给出固定点间各温度点的扩展不确定度及包含因子。 相似文献
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A. V. Kryukov 《Measurement Techniques》2006,49(12):1218-1223
The static characteristics of platinum resistance thermometers with different platinum purities were measured. It is shown
that in the 0–420°C range the ITS-90 method gives an error of less than 0.01°C, while in the 0–230°C range the error is less
than 0.006°C.
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Translated from Izmeritel’naya Tekhnika, No. 12, pp. 33–36, December, 2006. 相似文献
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Platinum resistance thermometers (PRTs) are widely used for accurate temperature measurements in industrial process control
as well as in testing and calibration laboratories. Industrial-type PRTs (IPRTs) are available with platinum wires of different
purity and can attain measurement accuracy at the level of few tens of millikelvin in a broad temperature range from −196 °C
to 550 °C and above. For such IPRTs, the most-used interpolation model (resistance versus temperature) is based on the Callendar–Van
Dusen (CVD) equation, which is also recognized in several industrial standards including IEC 60751 and the corresponding national
standards. In recent years, several studies have shown that systematic differences exist between the ITS-90 temperature (T
90) and the temperature calculated by the CVD function. When the CVD equation is used to fit experimental data, the difference
can be as large as several tens of millikelvin, even near a calibration point, i.e., of the same order of magnitude as the
experimental uncertainty routinely achieved in laboratory calibrations. In order to overcome the above limitations, many interpolation
models were proposed. The aim of this work is to assess the use of ITS-90 defining equations in precision laboratory calibrations
of IPRTs in the temperature range from −196 °C to 420 °C. Twenty IPRTs with W(100) ranging from 1.384 to 1.392 were calibrated by comparison against a standard PRT, and the experimental data were processed
using several interpolation schemes based on ITS-90 deviation functions with different degrees of freedom. The overall results
showed that any ITS-90-based scheme performs better than the CVD equation, suggesting that it be applied to a broad spectrum
of industrial and laboratory applications. 相似文献