共查询到19条相似文献,搜索用时 828 毫秒
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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。 相似文献
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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 相似文献
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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. 相似文献
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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。 相似文献
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T. Keawprasert T. Sinhaneti P. Phuuntharo S. Phanakulwijit A. Nimsamer 《International Journal of Thermophysics》2017,38(8):125
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. 相似文献
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论纳米光栅测量技术 总被引:4,自引:1,他引:4
邹自强 《纳米技术与精密工程》2004,2(1):8-15
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. 相似文献
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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). 相似文献
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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. 相似文献
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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. 相似文献