用一等标准铂电阻温度计检定二等标准铂电阻温度计结果分析

据据JJG160-2007标准铂电阻温度计检定规程,分析了用一等标准铂电阻温度计检定二等标准铂电阻温度计在锌凝固点、锡疑固点和水三相点上的测量结果不确定度。     

Improved High-Temperature Standard Platinum Resistance Thermometer

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.     

Calibration by Comparison of Platinum Resistance Thermometers Using Slow Resistance Bridges

Platinum resistance thermometers (PRTs) are calibrated at the highest level in fixed points, as specified in the International Temperature Scale of 1990 (ITS-90). However, in order to reduce cost and time, platinum resistance thermometers can also be calibrated by comparison. In the temperature range from ?100 °C to 300 °C, it is possible to achieve uncertainties as small as 5 mK. A PRT is calibrated by comparison by comparing its resistance reading with the temperature reading of a reference thermometer, placed at the same temperature inside the temperature-controlled calibration medium. The reference thermometer is commonly also a resistance thermometer, so the intrinsic measurement problem is the simultaneous measurement of two resistances. Four methods that perform this measurement are presented in this article. A special emphasis is given to the measurement with slow bridges. Slow bridges are not able to produce a stable resistance reading within 20 s after the connection of the PRT, so they are often considered to be unsuitable for calibration by comparison of PRTs. To overcome this problem, a special method that directly measures the ratio between the reference PRT and PRT under calibration is presented and analyzed. The analysis and measurement results proved that this method and consequently the slow resistance bridges are capable of performing calibration by comparison of PRTs at least at the same level as the conventional methods.     

铂丝位错特性对标准铂电阻温度计稳定性影响的研究

铂丝的位错是影响标准铂电阻温度计性能稳定性的重要因素之一。从微观角度出发,借助X射线衍射(XRD)分析方法,开展了退火时间对铂丝位错密度影响的研究,并利用标准铂电阻温度计退火实验数据进行了验证。结果表明:实际用于标准铂电阻温度计直径为0.07mm的新制铂丝(纯度99.999%)平均位错密度随着退火时间呈指数减小,经过100h退火后位错密度从1012cm^-2下降到1011cm^-2,300h后其位错密度基本保持稳定;新制标准铂电阻温度计在退火前300h其水三相点电阻值明显减小,退火300h后水三相点值变化量小于3mK并趋于平稳,此结果从热处理时间上与铂丝位错实验结果基本吻合。研究结果为标准铂电阻温度计制作工艺的提升及计量检定规程的修订提供技术支撑     

关于标准铂电阻温度计的检定规程的修订

本文介绍标准铂电阻温度计规程修订的原因、依据和修订的内容以及要达到的目标。     

关于标准铂电阻温度计的检定规程的修订

本文介绍标准铂电阻温度计规程修订的原因、依据和修订的内容以及要达到的目标。     

标准套管铂电阻温度计标准装置的不确定度评定

本文根据测量不确定度的评定方法,分析和计算了标准套管铂电阻温度计的不确定度,并对其开展的火箭发动机试验用低温热电偶的测量值的测量不确定度进行了评定。通过对标准装置和校准值的不确定度评定,掌握了标准套管铂电阻温度计标准装置及其开展的火箭发动机试验用低温热电偶的计量性能及误差来源,为国防计量标准的建立、运行与考核提供不确定度评定的依据。     

An AC Josephson Voltage Standard for AC–DC Transfer-Standard Measurements

We describe the traceability chain of length measurements at Centre for Metrology and Accreditation (MIKES) from atomic clocks to the lasers of primary interferometers. Crucial part of the traceability chain, an optical frequency comb generator linking optical frequencies to atomic clocks, is described in detail. The frequency comb generator is used in frequency calibrations of iodine-stabilized lasers, which are operated in compliance with the recommendations of the practical realization of the definition of the meter. Measured absolute frequencies of iodine-stabilized lasers, time records of the measurements, and the respective Allan deviations demonstrate the solid performance of the MIKES laser frequency standards. The results are in good agreement with the recommended values, as well as with the independent characterizations of the measured lasers     

Direct-Current Comparator Bridge for Resistance Thermometry

The design, construction, and performance of a dc bridge that covers the complete range of both platinum-and germanium-resistance thermometry in four ranges, 0-11 up to 0-11 000 ohms, is described. The bridge uses a potentiometric method based on the current comparator. In the design, emphasis has been placed on reducing the noise level, on obtaining a single-balance operation, and on providing a recorder output. Detector sensitivity and noise level (with a three-second time constant) permit full eight-decade bridge resolution to be achieved at a thermometer current of I mA on all ranges except the lowest, which requires 5 mA. Bridge errors are believed to be less than 10-7 of a reading or one step on the last dial, whichever is larger. A facility is provided for measuring the self-heating effect of the thermometer, even if the measured temperature is not constant. The bridge is also suitable for the measurement of four-terminal standard resistors over the same ranges.     

工业铂热电阻检定装置设备选型

本文通过对检定装置中主要测量设备的类型、用途、技术要求、国内外应用情况的介绍,并结合具体技术指标的综合分析,给出典型的设备参考,从而形成了有价值的检定装置设备选型参考方案。检定装置所采用的设备随着需求和技术的发展出现了非常大的改进,且类型较多,用途、技术指标和性能均有非常大的差异,尤其是电测仪器应该在以建立检定装置预期用途目的为根本的基础上合理选择配置。     

标准铂电阻温度计温度计算分析与应用

本论文针对标准铂电阻温度转换中运算量大、相关数据参数较多的问题,通过VB编程实现阻值温度的转换,提高了日常检定的工作效率、减少人工数据记录及处理产生的失误;同时还对分度表的计算方法进行了研究,并掌握其计算方法。     

二等标准铂电阻温度计标准装置不确定度分析

本文是对二等标准铂电阻温度计标准装置不确定度进行表示和评定。在实际运用中应注意人员、标准、环境、方法等不确定度分量进行评定。不确定度是测量工作的质量和测量结果可信赖程度和评价。按JJF1059-2012、JJG229-2010标准规定,对我单位的标准装置不确定度进行了详细分析,并按JJF(军工)3-2012要求对计量标准进行了重复性和稳定性考核,最后给出了计量标准装置不确定度评定。     

标准铂电阻温度计测量结果不确定度评定

本文以最常用的温度段（0-429．527）℃,以一等标准铂电阻温度计检定二等标准铂电阻温度计为例来分析标准铂电阻温度计的测量结果不确定度。     

Automatic Linearity Calibration in a Resistance Thermometry Bridge

The paper describes a new system that automatically calibrates the linearity of a resistance thermometry bridge or readout. A thermometry bridge, like all measuring and test equipment, must be regularly tested to ensure it is operating properly and accurately. Previously, this could only be done using special equipment and time-consuming procedures. The new technique described in the paper facilitates more frequent calibration of a resistance thermometry bridge. The system is incorporated into the design of the bridge and thus requires no extra equipment. Calibration, once initiated, is performed automatically by the bridge and is relatively fast. Tests were performed to evaluate the effectiveness of the automatic linearity calibration method. The uncertainty analysis and test results presented in the paper indicate that the technique is capable of quantifying resistance ratio measurement error as small as 2 ?? 10^?8 and is effective at identifying a wide variety of failures when they occur.     

标准铂电阻温度计自动测温装置的实现

标准铂电阻温度计作为ITS-90国际温标中(-200～650)℃段的量值传递的标准设备,具有稳定的化学和物理特性和良好的复现性;keithley2000系列数表以其优良的性价比被广泛使用,本文讨论将二者相结合,编写相应的软件以实现标准铂电阻温度计的自动温度测量.     

Bilateral Comparison of Aluminum Fixed-Point Cells Using Standard Platinum Resistance Thermometer

The objective of Project EURAMET 1114 (Bilateral comparison of a freezing point of aluminum) in the field of thermometry is to compare realization of a freezing point of aluminum (660.323???C) between the Dutch national laboratory VSL and the Slovenian national laboratory MIRS/UL-FE/LMK using a long-stem 25 ?? standard platinum resistance thermometer (SPRT). Both laboratories had participated in a number of inter-comparisons on the level of EURAMET and also on BIPM CCT level (VSL). MIRS/UL-FE/LMK laboratory recently acquired a new fixed-point cell which had to be validated in the process of intercomparison. A quartz-sheathed SPRT was selected and calibrated at MIRS/UL-FE/LMK at the aluminum freezing point and at the water triple point. A second set of measurements was made on the same SPRT and at the same fixed points at VSL (NL). After its return, the SPRT was again recalibrated at MIRS/UL-FE/LMK. In the comparison the W value of the SPRT was used. The results of the internal and external intercomparisons confirmed that the new aluminum cell of the MIRS/UL/FE-LMK realizes a temperature that agrees with the VSL aluminum fixed point within the uncertainty limits of both laboratories. Furthermore, the results of this bilateral-comparison were compared with results that both laboratories achieved in the EURAMET K4 (Project 820) and were found to be in agreement.     

Stability of Standard Platinum Resistance Thermometers and Rhodium Iron Resistance Thermometers for the Past Decade in NMIJ/AIST

In this study, the stability of four capsule-type standard platinum resistance thermometers (CSPRTs) has been checked by evaluating behavior of the calibrated values at each cryogenic fixed point of the International Temperature Scale of 1990 (ITS-90) below 273.16 K since around 2005. Performance of three capsule-type RhFe resistance thermometers (RIRTs) has been also observed at the triple points of Ne and \(e\hbox {-}\hbox {H}_{2}\). It is confirmed that CSPRTs and RIRTs are stable within the uncertainty of calibration at each low-temperature fixed point for a past decade except for one CSPRT. The resistance of the CSPRT was clearly affected by the accidental mechanical shock at TPW, although the variation of its calibration values was unclear at the triple points of Ar, \(\hbox {O}_{2}\) and Ne and was still within the uncertainty at the triple points of Hg and \(e\hbox {-}\hbox {H}_{2}\). And the CSPRT shows stable behavior after re-calibration again.