基于Mahr PLM600测长仪的圆锥管螺纹塞规基面中径的测量与不确定度评定

阐述了使用Mahr PLM600测长仪测量圆锥管螺纹塞规基面中径的原理、方法,结合图解及数学公式对其中的难点进行了阐述,并对基面中径测量结果不确定度进行了评定。     

圆锥螺纹塞规基面中径的测量

可在工具显微镜上用影象法或轴切法测量牙型角平分线垂直于螺纹轴线的圆锥螺纹塞规的基面中径,其具体步骤如下:1.先将圆锥螺纹塞规清洗干净顶在工具显微镜两顶尖之间。2.在距离塞规小端 l_o 的位置上(见图)     

大尺寸圆锥螺纹量规基面中径测量方法

根据大尺寸圆锥螺纹量规的测量需求,研制了一套基于三坐标测量机和激光干涉仪的大尺寸圆锥螺纹量规基面中径测量系统。对圆锥螺纹量规的基面中径进行了实际测量,并进行了测量不确定度评定。重复性测量和比对实验的结果表明,基面中径的测量结果达到预定的技术要求,所研制的测量系统适用于大尺寸圆锥螺纹量规的基面中径测量。     

圆锥螺纹塞规测量方法综述

随着现代工业的发展,对圆锥螺纹塞规的加工精度提出了更高的要求,如何提高圆锥螺纹塞规的测量准确度成为必须解决的重要课题.本文以接触式测量和非接触式测量分类方法为例,对比分析了国、内外现有的多种圆锥螺纹塞规基面中径测量方法及研究现状,认为利用CCD作为螺纹几何要素探测器件的视觉检测技术将是未来的发展趋势,随着模式识别、图像处理等相关技术的进步,随着机器视觉技术自身的成熟和发展,视觉检测技术将得到更为广泛的应用.     

圆锥螺纹塞规基面中径的测量及不确定度分析

本文详细介绍了在万能工具显微镜上采用轴测法测量圆锥螺纹塞规基面中径的原理与测量方法 ,并分析了测量不确定度     

圆锥螺纹塞规基面中径的测量及不确定度分析

本文详细介绍了在万能工具显微镜上采用轴测法测量圆锥螺纹塞规基面中径的原理与测量方法，并分析了测量不确定度。     

国标气瓶圆锥外螺纹基面中径的测量方法

气瓶螺纹的PZ系列和R系列,虽然均为气瓶圆锥螺纹,但是其螺纹基本牙型和参数定义不同,因此测量圆锥外螺纹基面中径的测针直径计算公式不同,且基面中径的计算公式也不同.文章依据给定的测量方法推导出相应的测针直径和基面中径的计算公式,并编制了测量软件,可以快速准确地测量气瓶圆锥外螺纹的基面中径.     

圆锥管螺纹基面中径测量不确定度评定

文章对针对美制和米制60°圆锥螺纹塞规,使用平面斜铁、标准锥形块、三针和量块,在立式光学计上测量螺纹规基面中径的方法进行不确定度分析,从而判定此方法能否满足标准规定的要求。     

用轴切法测量圆锥螺纹塞规基面中径

<正>0引言圆锥螺纹塞规主要用于综合检验密封管工件内螺纹。其中常见的有英制密封管螺纹量规(55°)和美制密封管螺纹量规(60°)。基准平面上的中径是圆锥螺纹塞规的主要参数,目前常用的测量方法有测球法和螺纹扫描法,但是这两种方法对于设备的要求比较高,不太适用于一般企业。本文提出了一种利用万能工具显微镜轴切法测量基面中径的方法,     

基于Mahr PLM600测长机的圆锥管螺纹环规基面中径的测量与不确定度评定

介绍了使用Mahr PLM600测长机测量圆锥管螺纹环规基面中径的原理、方法,结合图解及数学公式对其中的难点进行了阐述,并对基面中径测量结果不确定度进行了评定.     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

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.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

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.     

Analysis of the rate of propagation of the wave of change of boiling modes

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.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

水三相点复现的不确定度评定

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)。