HD-2004型岩心编录仪检定结果的不确定度评定

HD-2004型岩(矿)心编录仪是一款近年推向市场的仪器,广泛用于地质钻探岩心的β,γ编录。依据《辐射编录仪检定规程》(JJG(军工)41-2014),对校准HD-2004仪器的不确定度来源进行了分析、评定及统计,经过对30台仪器的统计,多数受校仪器其校准结果的不确定度不超过10%,γ测量方式最好不确定度为9.1%,!+γ测量方式最好不确定度为9.3%。     

医用加速器治疗辐射源检定中Excel软件的应用

医用加速器治疗辐射源由速调管、调制器、两通道以上的剂量监测仪表、准直器、控制器和床等组成,它是放射治疗癌肿瘤最重要的仪器。在检定时,根据JJG589-2001《外照射治疗辐射源》检定规程提供的方法,往往需要进行较为复杂的二维插值计算。为了提高检定时计算的效率和准确度,我们用Excel软件编制了计算程序,可以自动进行二维的内插计算。一、检定方法在实际的检定工作中,辐射源的辐射质、辐射野的均整度和对称性可由与模体配套的应用软件OmniPro直接读取。而对于射线束水吸收剂量的检定则较为复杂。1.X射线水吸收剂量的检定方法检定时仪…     

台式扭矩扳子检定仪检定方法探讨

扭矩扳子检定仪作为检定、校准扭矩扳子的主要标准装置,在计量检定机构和工业企业被广泛使用。特别是对于500N·m以下的中小型扭矩扳子,台式扭矩扳子检定仪（以下简称“检定仪”）由于安装便捷、加荷机构简单、性能稳定而得到广泛应用。根据JJG797—1992《扭矩扳子检定仪》检定规程,检定仪的检定设备为标准扭矩机或带力值砝码的检定杠杆,但在实际工作中上述两种检定设备使用起来较为困难,     

LPG加气机检定仪的检定

本文简要论述了LPG加气机检定仪的检定技术法规、加气机检定仪组成、技术要求和计量性能要求,并且叙述了加气机检定仪的检定程序。     

电导率仪检定过程中一些问题的讨论

本文存电导率仪检定的实践基础之上,结合JJG376-2007《电导率仪》国家计量检定规程,讨论了电导率仪检定过程中存在的一些问题,并提出了相应的解决办法,为电导率仪的检定工作者提供参考。     

不同加载方式对扭矩测量结果的影响分析

扭矩扳子检定仪对扭矩扳子检定应用越来越广泛。扭矩检定仪检定扭矩扳子时,加载装置产生的误差远远大于设备仪表和力矩传感器所产生的误差。本文探究扭矩检定仪的结构组成,分析扭矩扳子检定仪的加载方式和加载装置,对不同因素影响的误差进行研究。     

电感式量块检定仪的应用技术

本文介绍电感式量块检定仪测试系统的基本组成原理,应用国内外电感式量块检定仪时进行的不确定度分析及验证量块检定仪检定/校准结果是否准确可靠的方法.     

指示表检定仪示值误差校准的新方法

本文从指示表检定仪的结构原理出发 ,概述了指示表检定仪的新发展 ,对现有检定规程中的检定方法作了较深入分析 ,并由此提出新的检定方法     

色谱检定仪检定规程有关问题的说明

一、概述色谱检定仪是检定气相色谱仪的主要设备。它用来检定气相色谱仪的柱箱温度稳定性、程序升温重复性、基线噪声、基线漂移和衰减器换档误差。它的量值准确与否 ,直接关系到气相色谱仪检定结果的准确性。为了对色谱检定仪的性能和技术指标进行统一的评定 ,以保证气相色谱仪检定结果的准确、可靠。由国家质量技术监督局授权 ,国家标准物质研究中心起草、天津市计量技术研究所参加编写了色谱检定仪检定规程。本文就规程中有关问题及检定中应该注意的事项作一说明。色谱检定仪检定规程中主要技术指标如表 1所示。表 1　色谱检定仪主要技术…     

不能单单送检测微头

不能单单送检测微头工厂计量室的计量人员在送检百分表检定仪时，为了省事，往往只送检测微头。计量检定部门的检定人员在检定百分表检定仪的示值误差时，也就将送检的测微头安装在其它同厂生产的百分表检定仪上检定示值误差，并以此检定结果作为送检测微头的百分表检定仪...     

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.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

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.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。     

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.