共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
5.
针对JJG4-2015《钢卷尺检定规程》中提到,钢卷尺可以通过满足测量不确定度要求的其他方法进行测量的情况,开展不确定度的分析研究,采用全自动检定装置作为测量标准,进行钢卷尺示值误差项目的测量结果不确定度的分析与评定。 相似文献
6.
1测厚尺在房屋面积测量过程中,对带有门框、窗户框的墙体进行厚度测量时,由于门框、窗户框凸出墙体,无法用直尺、卷尺直接测量。对此,我们设计了测厚尺,见图1所示。工作原理:主尺3与副尺1合拢时,钢卷尺2收缩处于零位;测量时,拉开副尺(钢卷尺伸长)对墙体进行测量,并按图中箭头A所指方向对准指示线4读钢卷尺伸长值,即墙厚尺寸。2手持激光测距仪水平架在测量挑出墙外的檐廊、独立柱的雨篷、单排柱的车棚、货棚、站台等的水平投影时,往往因被测量对象太高而不好测量。使用手持激光测距仪水平架(以下简称水平架),见图2,可将高处被测量对象的水平… 相似文献
7.
8.
9.
本文根据标准钢卷尺检定装置,结合JJG4-1999《钢卷尺检定规程》的要求,对量油尺测量结果的不确定度进行评定。 相似文献
10.
11.
A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
12.
An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
13.
14.
15.
水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。 相似文献
16.
17.
18.
Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
19.