镀层测厚仪标准样块制作及其不确定度评定

金属镀层的厚度一般是用镀层测厚仪或涂层测厚仪来测量的,但是镀层测厚仪目前还没有校准规范,而涂层测厚仪的检定,JJG 818—2005《磁性、电涡流式覆层厚度测量仪检定规程》是用非金属厚度片作为标准件,故而与被测件的介质不一致,测量结果的可靠程度无法确定,文章介绍了在量块上镀上不同的金属介质,用常用端度计量仪器确定介质厚度,并对其进行不确定度评定,以及用来校准镀层测厚仪的方法。     

无损检测技术在雷达波吸收材料研究中的应用

采用ＮＤＴ方法中涡流检测技术研制出吸波涂层专用测厚仪。这种涡流测厚方法适用于涂敷在铝合金基材上的铁磁性吸波涂层，测量简便、准确，对涂层无损坏，解决了在大型工件上施工时吸波涂层厚度的控制问题。     

同位素测厚仪的研制

厚度测量包括板材、带材、管材的厚度测量以及涂层的厚度测量,在生产过程中大多采用厚度连续测量方式,这种连续测量厚度的仪表称为测厚仪。目前宝钢测厚仪主要应用在冷轧、热轧、钢管区域,测厚仪全部从国外公司进口,分别是德国FAG和IMS、美国RMC、日本TOSHIBA。射线式测厚仪是利用射线透过物质后强度发生衰减,衰减的程度与物质的厚度相关的原理研制而成,主要分为同位素测厚仪和X射线测厚仪。在宝钢技术人员的努力下,终于研制成了第一套完全自主知识产权的测厚仪系统,并成功的应用在宝钢股份2030冷轧厂CM12机组。一、工作原理由放射…     

用红外技术测量涂层厚度

涂敷在基材上的胶粘剂涂层厚度,无论是湿的或干的,均可采用红外技术进行极精确的测定。红外工程公司(Infrared Engin-eering)的 SM_4测厚仪能够测量胶粘剂涂层厚度,其精度达到0.2克/米~2。同普通的测量胶粘剂厚度的方法(如β测厚仪)相比,使用红外测厚仪有许多操作优点。SM_4是以背反射的方式(测量胶粘     

几种新型测厚仪

《Metal Finishing》1982年第3期介绍了几种新型测厚仪。Elcometer 255F型袖珍测厚仪:用于测量铁质材料上的非磁性涂层厚度,量程为:0—     

接触式在线测厚仪的静态校准板

概述接触式在线测厚仪是冷轧钢板在线检测的高精度测量仪器。该测量仪能实时测量轧制钢板的厚度，并将测得结果运馈给自动厚度控制系统AGC（AutomaticGaugeControl）。AGC根据测厚仪测得的结果，调整轧辊的缝隙来控制轧制钢板的厚度。因此，测厚仪的测量精确度直接影响轧制钢板的质量，必须对每台测厚仪进行核准。但是，对装调过程中的测厚仪进行在线动态检测受条件的限制。所以，只能模拟测厚仪的在线工作状态，对其进行静态校准。为此，提出了一种新的接触式在线测厚仪的静态校准板，解决了模拟测厚仪在线检测状态下，对测厚仪静态校…     

射线检测仪表在冶金工业中的选型误区

计射线检测仪表广泛用于现代冶金企业,其一般按照测量参数分为测厚仪、凸度仪、涂层仪、密度计、料位计、浓度分析仪等。但由于许多设计人员对射线测量仪表不熟悉,在设备选型上没有按需配置,导致设备在生产中不能充分发挥作用,出现了设备闲置,资金浪费,维护成本高,甚至于难以维护,只能拆除的后果。误区一:用X射线测厚仪完全替代同位素测厚仪由于X射线测厚仪具有噪音小,准确度高,能量可以自动调节等优点,目前已得到广泛应用。同时由于同位素测厚仪涉及到放射性同位素许可证及回收协议等一系列复杂的手续,而且同位素测厚仪具有一定的放射性危…     

X光测厚仪原理与系统应用

工业用测厚仪有接触式和非接触式两种,通常在线测量使用非接触式测厚仪。X光测厚仪应用X射线穿过被测材料的衰减来检测厚度。这种测厚仪在热轧机工作现场得到广泛应用。本文通过对热轧机所使用的X光测厚仪的分析,介绍了测厚仪的工作原理,描述测厚仪的射线发射和接受装置,对于影响测厚精度的各种因素进行分析和消除,对测厚仪硬件系统的组成、操作系统的结构和功能进行了说明。     

透射式辐射测厚仪主要技术性能指标的测试方法

本文所介绍的透射式辐射测厚仪主要技术性能指标的测试方法，是根据我国有色金属压延生产线上使用的测厚仪所存在的问题，对影响测厚仪测量精度及工作状态的因素进行了简要的分析，并提出了解决的方法。     

X射线测厚仪在莱钢1500可逆式轧机中的应用

对RM215X射线测厚仪的结构和原理进行了深入的分析，详细分析了测厚仪在可逆式冷轧机中的应用，对AGC如何使用所测厚度进行了详细说明。     

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)。