甲醛气体检测仪校准中的常见问题

通过对不同原理的甲醛气体检测仪介绍,分析不同原理的仪器优势和劣势,为用户实际使用和实验室后续检测提供思路。介绍了甲醛气体检测仪检定装置及甲醛气体检测仪的校准方法,同时结合实际工作总结出,甲醛气体检测仪校准过程中可能会遇到的一些问题,并提出参考建议。     

磷化氢气体检测仪校准方法探讨

正一、磷化氢气体检测仪校准存在的问题目前,磷化氢气体检测仪的检定或校准工作难以开展,大多数使用单位疏于安全管理,导致难以保证检测仪量值准确可靠和及时报警,存在较大的安全隐患。主要表现在:(1)国内没有颁布实施磷化氢气体检测仪的检验标准和技术规范,缺少相应的计量技术指标。(2)由于磷化氢气体属于剧毒气体且化学性质活泼,标准气体的供应商很少,难以买到标准气体。(3)标准气体的保存期限较短,一般不大于6个月,气体检测成本较高。     

便携式智能气体配气装置的设计

在对气体分析仪或气体监测系统进行检定或校准时,根据现场需求提出了一种基于质量流量控制器的动态智能气体配气装置的设计方案.该装置集浓度计算、配制气体、控制流量和数据处理等功能于一体,采用模糊控制算法,连续配制并输出浓度值连续可调的混合标准气体.该装置可满足实验室和现场对多种气体检测仪的检定和校准工作,便于携带,并可节约成本,提高工作效率,具有很好的应用前景.     

JJG1022-2016《甲醛气体检测仪检定规程》解读

<正>一、规程修订背景及目的中国计量科学研究院根据市场需要在国内率先开展了甲醛气体检测仪的计量校准和测试研究,先后研制了甲醛扩散管标准气体、甲醛计量测试和校准试验装置等。近3年来,开展了近2000台甲醛检测仪的计量校准和测试,取得了宝贵的第一手市场仪器资料和检定/校准经验。对JJG1022-2007《甲醛气体检测仪检定规程》(以下简称"原规程")存在的问题有较深刻的认识。并且近年来在甲醛配气技术方面取得了很好的     

开放对射式可燃气体检测仪示值误差测得值不确定度评定分析

本文依据JJG 693-2011《可燃气体检测报警器检定规程》,采用特制的专用校准装置,对开放对射式可燃气体检测仪进行校准,并分析评定了示值误差测得值不确定度,可一定程度地保障检测仪器检测结果的准确、可靠.     

氢气纯度奥氏气体分析仪的校准与不确定度评定

氢气纯度奥氏气体分析仪是一种监测生产氢气纯度的仪器,目前国家还没有检定规程或校准规范用于该类分析仪的检定或校准。因此解决氢气纯度奥氏气体分析仪的校准已成当务之急。文章给出了一种使用有证标准气体对奥氏气体分析仪进行校准的方法,并给出了测量不确定度的评定方法。     

气体检测仪检定规程中几个问题的探讨

为保障石油化工等行业的安全生产、实现对大气中污染气体的实时监测,各类气体检测仪、报警器获得广泛应用。本文结合实际检定工作,针对各类气体检测仪检定规程的共性问题进行探讨,指出"示值误差"的真正含义是系统测量误差的一个分量并分析了检定时气体标准物质的选择;规程中"仪器的重复性"一词并不严谨,应为"测量的重复性";某些规程虽然对检定过程中环境温度波动无要求,但在检定过程中环境温度应尽量保持稳定;对一些数字式气体检测仪,报警动作值就是设置值,其报警误差为零;各类气体检测仪规程中对漂移的要求均低于相关国家标准。     

关注硫化氢气体检测仪重复性的计算

近年来．随着安全防护意识的不断提高，在安装使用现场．硫化氢气体检测仪报警点和满量程被使用单位不断降低。JJG695—2003《硫化氢气体检测仪》检定规程在2003年发布时．     

硫化氢气体检测仪检定注意事项及常见故障处理

硫化氢气体检测仪作为检测环境中硫化氢气体含量的计量仪器,要保证其检测结果的准确可靠,以便能够及时发现硫化氢气体泄漏,有效预防人身伤害以及爆炸事故的发生,依法合规地开展硫化氢气体检测仪的检定和正确地使用维护非常重要。本文在总结大量日常检定工作经验的基础上介绍了硫化氢气体检测仪在检定过程中需要注意的细节问题,并且针对一些常见的故障及其产生的原因进行了分析,提出了具体的解决方法。     

硫化氢气体检测仪日常使用中的问题

硫化氢气体检测仪作为安全生产的重要监测仪表,对防止发生中毒事故、减少人员伤亡起到了非常重要的作用。但在日常使用和管理中存在一些问题,并未引起足够重视。下面笔者结合多年从事硫化氢气体检测仪检定和维修的经验,针对这些问题进行探讨。     

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.     

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.     

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.     

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)。