透湿性测试的仲裁方法——称重法

透湿性测试方法包括称重法和传感器法两大类,最早使用的是称重法。称重法是透湿性测试的仲裁方法,传感器法的测试数据体系需要用称重法数据进行标定。     

薄膜水蒸气透过率测试方法的分析与比较

介绍了薄膜透湿性测试的发展历程,对称重法和传感器法从测试原理、精度误差等方面进行了简单比较,并介绍了称重法设备的最新进展.     

从透湿性测试的发展趋势看增重法与减重法

称重法是透湿性测试的仲裁方法,具有结构简单、操作方便以及设备成本低等优点,实际应用非常广泛。作为透湿杯的发展变形,容器可以是袋、瓶或其他一些容器。称重法包括增重法和减重法两种测试方法,本文从透湿性测试的发展趋势分析这两种方法未来的发展与应用。     

关于提高称重法水蒸气透过率测试设备测试性能的分析

称重法是进行材料水蒸气透过率的基础测试方法,也是历史最悠久、应用最广泛的一种测试方法。称重法所包含的几种测试方法(例如增重法、减重法等)最初都需要人工操作来完成测试,相关仪器的自     

单井产液量计量车研究与应用

当前外围油田原油集输多采用单管环状流程,为提高油田开发经济效益,降低开发成本,急需研究一种精确、方便、实用的单井计量技术。单井产液量计量车采用称重法和质量流量计法两种方法,具有测试精度高、测量时间短、温度范围宽等特点,特别适合北方寒冷气候,经现场测试效果较好。     

基于LabVIEW的液压缸密封件泄漏试验测试系统设计

设计了一种基于LabVIEW的液压缸密封件泄漏试验测试系统,方便有效地实现了对密封件泄漏的测试并利用电子天平称重法对泄漏进行检测,同时通过RS232与计算机通讯实现上位机对泄漏量的数据采集、曲线绘制和结果分析等。该系统具有测试精度高、自动化程度高,测试效率高等特点,可为密封件密封性能测试提供实验支持。     

材料透湿性测试方法介绍——传感器法

20世纪70年代，传感器法开始应用在透湿性测试领域中，在此之前使用的都是称重法，通过30多年的发展，它已成为一种重要的测试方法，应用范围十分广泛。通常的透湿性测试传感器法主要有：红外线检定法、动态相对湿度测定法和电解分析法三种。     

国家蒸汽流量站标准装置的研究

详细分析了国家蒸汽流量站新建的冷凝称重法蒸汽流量标准装置,该装置采用冷凝称重法对蒸汽流量仪表实流标定,并进行了稳定性试验,稳定度达到0.20%.该方法溯源性好、准确可靠.国家蒸汽流量站的建立对于深入开展蒸汽流量能源的计量具有重要的意义.     

平衡环境型房间量热计凝结水量测量设计

量热计法室内侧制冷量计算公式,未考虑测量中小冷量空调器制冷量时空气处理柜除湿造成的误差。为排除此误差对测试结果的影响,采用称重法分别测量量热计内、外室加湿水及被测机的凝结水。利用基于称重法设计的量热计测得5台被测机的2组数据并进行分析,结果表明,当空调器的额定制冷量低于测试室输入功率时,空气处理柜的除湿量会增大测量偏差,且随着空调器制冷量的降低偏差增大。并对室内侧制冷量计算公式进行修正,以提高计算精确度。     

用称重法检定液化石油气加气机的论述

本文全面地介绍了用称重法检定液化石油气加气机的技术要求、计量检定、数据处理与检定结果的不确定度评定.     

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.     

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。     

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.     

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.     

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。