湿度传感器的修正值测量结果的不确定度评定

依据JJF1076—2001《湿度传感器校准规范》,在满足温度(23±5)℃;相对湿度:≤85%RH的条件下,使用Optidew Vision精密露点仪、YGM-C600温湿度检定箱对测量范围为(10~100)%RH,分辨力为0.1%RH的湿度传感器进行校准,开展湿度传感器的修正值的试验研究,给出其测量结果的不确定度评定方法和步骤。     

基于传感器阵列的野外基线环境参数自动测量系统研制

为了保证野外测距精度,研制了一套环境参数自动测量系统,该系统通过在野外基线沿线布置密集的气温、气压与湿度传感器阵列,精确测量光路气温、气压及湿度等环境参数,进行空气折射率修正。采用μ-base测距仪在不同气候条件下进行验证实验,测量距离为144 m。实验结果表明,采用该系统测量环境参数,进行空气折射率修正,其修正误差引入的距离测量不确定度优于3.0×10^-7(k=2)。     

红外体表温度计示值修正值测量结果的不确定度评定

笔者结合校准某高校保障复学送检的580台红外体表温度计的工作实践,通过对红外体表温度计示值修正值测量不确定度的分析和评定,以期为校准活动和仪器日常使用提供技术支持。一、概述1.测量依据:JJF1107-2003《测量人体温度的红外温度计校准规范》。2.测量环境条件:温度18℃~22℃,湿度(30~70)%RH,无强环境辐射,无强空气对流。3.测量对象:红外体温计(TD133),分辨力0.1℃,MPE=±0.3℃。     

呼出气体酒精含量测量仪示值误差的不确定度评定

一、概述1.测量依据JJG657-2006《呼出气体酒精含量探测器》检定规程。2.测量环境条件室内温度:(25±2)℃;湿度:≤80%RH;电源电压:(220±22)V。3.测量标准液态有机气体配气装置:配置乙醇标准气体浓度的不确定度U=2%,k=2。无水乙醇:纯度为99.8%,U=2%,k=2。微量进样器:规格为10μL,U=0.03μL,k=2。     

户用超声波燃气表测量结果不确定度评定

正一、概述1.测量依据:JJG(京)3001-2017《户用超声波燃气表检定规程》。2.测量条件:温度为20℃±2℃,湿度为30%RH～75%RH。3.测量标准:临界流文丘里喷嘴法气体流量标准装置,扩展不确定度优于0.33%(k=2)。4.测量对象:G4型超声波燃气表。     

十分表示值误差测量结果的不确定度评定

正一、测量依据JJF1059.1-2012《测量不确定度评定与表示》。二、测量环境条件温度:(20±10)℃,湿度:≤80%RH。三、测量标准(0.5~100)mm三等量块,测量不确定度为U99=0.10+1L。四、被测对象十分表,型号(0~10)mm,出厂编号:53088,生产厂家:日本。五、测量方法在规定条件下,将十分表固定在表架上,将一组三等量块依次放于两测量面之间,十分表的示值     

环境试验设备温度波动度测量不确定度评定

正一、概述1.测量依据参考JJF1101-2019《环境试验设备温度、湿度参数校准规范》。2.测量环境温度24℃,相对湿度63%。3.测量标准以温度巡回检测仪作为测量标准,测量范围-80℃～300℃,分辨力0.01℃,修正值扩展不确定度U=0.06℃(k=2)。     

无线温度验证仪测量装置不确定度分析

温度验证仪测量装置的性能直接影响到验证仪的测量结果,文章介绍了温度验证仪的组成和计量特性,分析了影响示值结果不确定度的相关因素,对无线温度验证仪温度偏差校准结果的不确定度进行了评定,计算得出温度验证仪测量结果的扩展不确定度为U=0.02℃(k=2)。根据各不确定度分量判断出对装置性能影响较大的因素,并提出可行性的改进方案。     

气相色谱-质谱联用仪信噪比测量结果不确定度评定

正一、概述1.测量依据JJF1059.1-2012《测量不确定度评定与表示》、JJF1164-2011《台式气相色谱-质谱联用仪校准规范》。2.环境条件温度:15℃～27℃;湿度:≤75%RH。3.测量标准异辛烷中八氟萘溶液标准物质(100pg/μL,Urel=2%,k=2)。4.测量对象气相色谱-质谱联用仪(型号:7890A/5975C;编号:1306/25009;EI(电子轰击)源)。     

一等大量块(125～1000 mm)检定装置

量块的测量是长度计量的重要基础.文中的装置采用了高精度的633 nm碘稳频氦氖激光器和543 nm热稳频氦氖激光器各一台,分别将不同波长的激光光束入射到典型的迈克尔逊干涉仪中,使放置在测量光路中的量块与平晶研合在一起的组合体和参考镜进行干涉,利用CCD摄像机获取干涉图像,同时测量量块温度及空气折射率(或环境参数),一同输入计算机中进行处理计算得到测量结果.对于125～1000 mm量块的测量难点是保证温度要稳定、均匀、偏离20 ℃的范围要小.为此,设计了可高精度控温的仪器箱,可调节温度到17～23 ℃,温度变化率小于0.01 ℃/h,从而实现量块线膨胀系数的测量.该装置的量块长度测量不确定度达到U99 =0.02 μm+0.2×10-6 L,量块线膨胀系数测量的不确定度可达U99 =0.2×10-6 ℃-1.     

高精度空气折射率测量系统设计与实现

针对商用空气折射率测量装置受到传感器采集性能和解算公式准确度的影响使得实际测量精度较低的问题,基于便携式多环境参数采集装置,设计了一套空气折射率测量系统,采集环境中的温湿度、大气压强状态信息,对3种折射率间接测量公式进行误差分析,并和商用环境补偿器进行性能对比。实验结果表明:在压强为100.17~100.21kPa,温度为21.1~21.9℃,湿度为45.9~58.0% RH的实验条件下,该测量系统的测量偏差比商用环境补偿器低2.69×10^-7。     

光干涉法高精度材料线膨胀系数测量

中国计量科学研究院研制的高精度材料线膨胀系数测量装置,满足温度范围为5～40 ℃、被测件长度在20～1 000 mm之间的线膨胀系数测量。采用激光干涉法测量被测件长度变化量,用高精度温度传感器测量温度值。设计了热平衡式干涉镜,利用空气折射率修正和零位误差补偿技术,保证在5～40 ℃变温范围内激光干涉仪的测量精度。以500 mm标准量块作为测量对象,线膨胀系数测量结果与德国物理技术研究院(PTB)测量结果的相对偏差为0.2%。材料线膨胀系数测量不确定度达到3×10^-8K^-1。     

激光量块干涉测量中传感器的应用和校准

本文介绍了双波长激光量块干涉仪中使用的温度、湿度和气压传感器,描述了其工作原理、设计方案、测量不确定度以及校准方法。这些传感器同样可用于其他高准确度长度测量的激光干涉系统中。     

Improving the Traceability of Meteorological Measurements at Automatic Weather Stations in Thailand

A joint project between the National Institute of Metrology Thailand (NIMT) and the Thai Meteorology Department (TMD) was established for improving the traceability of meteorology measurements at automatic weather stations (AWSs) in Thailand. The project aimed to improve traceability of air temperature, relative humidity and atmospheric pressure by implementing on-site calibration facilities and developing of new calibration procedures. First, new portable calibration facilities for air temperature, humidity and pressure were set up as working standard of the TMD. A portable humidity calibrator was applied as a uniform and stable source for calibration of thermo-hygrometers. A dew-point hygrometer was employed as reference hygrometer and a platinum resistance thermometer (PRT) traceable to NIMT was used as reference thermometer. The uniformity and stability in both temperature and relative humidity were characterized at NIMT. A transportable pressure calibrator was used for calibration of air pressure sensor. The estimate overall uncertainty of the calibration setup is 0.2 K for air temperature, 1.0 % for relative humidity and 0.2 hPa for atmospheric pressure, respectively. Second, on-site calibration procedures were developed and four AWSs in the central part and the northern of Thailand were chosen as pilot stations for on-site calibration using the new calibration setups and developed calibration procedures. At each station, the calibration was done at the minimum temperature, average temperature and maximum temperature of the year, for air temperature, 20 %, 55 % and 90 % for relative humidity at the average air temperature of that station and at a one-year statistics pressure range for atmospheric pressure at ambient temperature. Additional in-field uncertainty contributions such as the temperature dependence on relative humidity measurement were evaluated and included in the overall uncertainty budget. Preliminary calibration results showed that using a separate PRT probe at these AWSs would be recommended for improving the accuracy of air temperature measurement. In case of relative humidity measurement, the data logger software is needed to be upgraded for achieving higher accuracy of less than 3 %. For atmospheric pressure measurement, a higher accuracy barometer traceable to NIMT could be used to reduce the calibration uncertainty to below 0.2 hPa.     

数学摆台法的超低频加速度校准

建立了基于数学摆台法的超低频加速度校准装置,解决了线振动台超低频加速度信噪比低的问题,对相关校准具有参考价值和借鉴作用。根据低频噪声理论,在建立激光测振仪的功率谱密度模型基础上,提出了位移噪声的定量评价方法,通过实验验证了所提方法的正确性。对数学摆台的虚拟摆臂、激励传递系数进行了实验测量,对校准装置的测量不确定度进行了评定。该装置实现了加速度计在频率范围0.001～0.1Hz、加速度范围5×10^-7 ～1×10^-2m/s² 的绝对法校准。     

论纳米光栅测量技术

作者及其同事们经过20多年努力将计量光栅技术提高到了纳米量级和亚纳米量级，并进行了大面积推广应用，形成了一整套纳米光栅测量技术，该文为对这套技术的综合论述．首先回顾了刻线技术的发展历史，指出中国古代曾作出杰出贡献．归纳了发展计量光栅技术的5个阶段和4项内容．给出纳米光栅的定义和两个特点，并通过作者和同事们的光栅制造过程说明，纳米光栅实质上是一种刻录、固化到光栅基体上的光波波长．它为纳米测量领域提供了一种新途径、新方法，与激光干涉仪等现有纳米测量方法相比，具有自己独特的优点．文中讨论了纳米光栅的读取技术与信号处理技术，提出了纳米光栅细分误差的错位测量法．还讨论了与纳米光栅相关的纳米机械，介绍了作者和同事们的科研成果，圆柱、导轨等的机械精度已经进入了纳米量级．最后讨论了纳米光栅与激光干涉仪以及高等级量块的比对结果．     

Prism-pair interferometry by homodyne interferometers with a common light source for high-accuracy measurement of the absolute refractive index of glasses

A prism-pair interferometer comprising two homodyne interferometers with a common light source was developed for high-precision measurements of the refractive index of optical glasses with an uncertainty of the order of 10(-6). The two interferometers measure changes in the optical path length in the glass sample and in air, respectively. Uncertainties in the absolute wavelength of the common light source are cancelled out by calculating a ratio between the results from the interferometers. Uncertainties in phase measurement are suppressed by a quadrature detection system. The combined standard uncertainty of the developed system is evaluated as 1.1×10(-6).     

Refractometer for tracking changes in the refractive index of air near 780 nm

A new system, consisting of a double-channel Fabry-Perot etalon and laser diodes emitting around 780 nm, is described and proposed for use for measuring air-refractive index. The principle of this refractometer is based on frequency measurements between optical laser sources. It permits quasi-instantaneous measurement with a resolution of better than 10(-9) and uncertainty in the 10(-8) range. Some preliminary results on the stability of this system and the measurements of the refractive index of air with this apparatus are presented. The first measurements of the index of air at 780 nm are, within an experimental uncertainty of the order of 2 x 10(-8), in agreement with the predicted values by the so-called revised Edlén equations. This result is, to the best of our knowledge, the first to extend to the near IR the validity of the revised Edlén equation derived for the wavelength range of 350-650 nm.     

Separation of measurement of the refractive index and the geometrical thickness by use of a wavelength-scanning interferometer with a confocal microscope

An improved system for the separate measurement of the refractive index and the geometrical thickness that constitutes a hybrid configuration of a confocal microscope and a wavelength-scanning heterodyne interferometer with a laser diode is presented. The optical path difference can be measured in less than 1 s, which is 10 times quicker than with the low-coherence interferometry previously used, and with a resolution of 10 mum with a fixed reference mirror. Separate measurement of the refractive index and the geometrical thickness of glass plates was demonstrated by use of the arrangement in place of the low-coherence interferometer used previously.