基于闭环制冷机的平衡氢三相点复现装置

为了解决平衡氢三相点复现装置复现难度大、耗时长、效率低的问题,研制了基于闭环GM制冷机的新型平衡氢三相点复现装置。采用准绝热方法复现平衡氢三相点;基于Labview程序,实现了复现过程的自动测量与控制。该套装置不仅提高了工作效率,而且提升了复现性。实验结果表明:该套系统平衡氢三相点的复现性优于0.05 mK,标准不确定度优于0.1 mK。     

标准铂电阻固定点复现自动监测装置的设计与应用

文章通过介绍一种标准铂电阻固定点复现自动监测装置,分析了固定点复现过程中的关键相变机理,阐明准确的计算固定点复现过程中机理变化时间,进而实现固定点复现的自动监测对标准铂电阻温度计量值传递的重要作用。     

标准高色温光源的实现

本文提出一种再现标准高色温光源的新方案,并以标准照明体D_(65)的复现为例讨论了该方案的特点和复现效果。     

Pd-C高温共晶点复现技术研究

设计了Pd-C高温共晶点复现装置,包括复现用高温均热炉炉体、温度控制系统、真空泵、充气保护装置、水冷系统、复现用的石墨坩埚、二等B型标准热电偶和Pt-Pd热电偶等。在此基础上进行了石墨坩埚的灌注和共晶点复现,并对复现的试验数据进行了相应的分析。结果表明本装置温度复现性可以达到0.2℃以下。     

Pd-C高温共晶点复现装置研制

主要针对Pd-C高温共晶点复现装置的组成进行介绍,其中包括复现用高温均热炉炉体、温度控制系统、真空泵、充气保护装置、水冷系统、复现用的石墨坩埚、二等B型标准热电偶和Pt-Pd热电偶等。针对石墨坩埚的灌注和共晶点复现过程进行了描述,根据复现的试验数据进行了相应的分析。     

戊烷标准气体量值的复现性及性能评价

本文介绍了重量法制备戊烷标准气体量值复现及评价的理论基础、实验原理、复现过程及量值性能指标的评价。     

mt法高压天然气流量标准装置影响因素分析及控制措施

国家石油天然气大流量计量站南京分站的mt法高压天然气流量标准装置用于复现高压天然气的质量流量,对临界流文丘里喷嘴进行校准。通过数值模拟、实验分析等方法对影响标准装置复现质量流量以及影响校准临界流文丘里喷嘴流出系数结果的因素进行了分析,制定了相应的控制措施,有效地保证了mt法天然气流量标准装置的计量性能,可使复现的质量流量的不确定度小于0.06%(k=2),校准临界流喷嘴流出系数的不确定度小于0.12%(k=2)。     

小角度检查仪复现标准角度的不确定度评定

本文介绍了小角度检查仪复现标准角度时不确定度的来源及大小 ,由于小角度检查仪没有仪器示值误差这项技术指标 ,因此对其复现标准角度的不确定度进行评定显得尤为重要。     

坐标测量机面向任务的测量不确定度评定

基于产品几何技术规范,分析了坐标测量机面向任务的测量不确定度主要来源;重点讨论了量值特性指标测量复现性的定义与特点,并针对坐标测量机的测量任务,提出引起坐标测量复现性的主要因素,研究了进行复现性指标评价的实验方案,建立了复现性评定的数学模型;通过孔径测量实例分析,介绍了坐标测量机面向任务的测量不确定度评定方法。结果表明,孔径测量结果的合成标准不确定度为3.2 μm,其中测量复现性的不确定度分量高达2.5μm,在测量结果不确定度中所占比重最大。     

PTB所建激光干涉振动一次绝对校准标准简析

按照ISO/16063-11：1999《激光干涉绝对法振动校准》所述,激光干涉振动一次绝对校准方法主要有条纹计数法、最小点法与正弦逼近法三种,其复现频率范围为1Hz～10kHz.而德国联邦物理技术研究院（PTB）现已建立和保存的低频、中频、高频振动激光干涉一次绝对校准标准的复现频率范围则达0.1Hz～20kHz.此外,PTB还实现了旋转运动物理量值--角加速度的复现;其复现频率范围也达到0.3Hz～1kHz.作为曾在PTB1.22实验室进行过研究工作的访问学者,作者旨在通过对PTB所建激光干涉振动一次绝对校准标准的     

Quasi-convex reproducing kernel meshfree method

A quasi-convex reproducing kernel approximation is presented for Galerkin meshfree analysis. In the proposed meshfree scheme, the monomial reproducing conditions are relaxed to maximizing the positivity of the meshfree shape functions and the resulting shape functions are referred as the quasi-convex reproducing kernel shape functions. These quasi-convex meshfree shape functions are still established within the framework of the classical reproducing or consistency conditions, namely the shape functions have similar form as that of the conventional reproducing kernel shape functions. Thus this approach can be conveniently implemented in the standard reproducing kernel meshfree formulation without an overmuch increase of computational effort. Meanwhile, the present formulation enables a straightforward construction of arbitrary higher order shape functions. It is shown that the proposed method yields nearly positive shape functions in the interior problem domain, while in the boundary region the negative effect of the shape functions are also reduced compared with the original meshfree shape functions. Subsequently a Galerkin meshfree analysis is carried out by employing the proposed quasi-convex reproducing kernel shape functions. Numerical results reveal that the proposed method has more favorable accuracy than the conventional reproducing kernel meshfree method, especially for structural vibration analysis.     

An investigation of the uncertainty in reproducing the units of pulsed electric and magnetic field strengths in a standard system for producing very-short electromagnetic pulses with a rise time of 20 psec

A method of reproducing the units of pulsed electric and magnetic field strength in a standard system with a pulse rise time of less than 20 psec, constructed using a “cone over a plane” field-generating system is considered. The components of the uncertainty in reproducing the units are analyzed. The extended uncertainty is not greater than 6.5%.     

渐开线齿面和齿线倾斜角参数的新国家(乌克兰)长度单位标准

说明使用干涉测量方法复制齿线标准的原理。分析它的实验计量结果,介绍新的检定系统。     

New State Primary Standard for the Hardness of Metals on the Shore D Scale

The results are given of metrological investigations of a new State primary standard GÉT 161-01 for the hardness of metals on the Shore D scale. The standard is intended for reproducing and transferring the Shore D scale in the range 20-140 HSD.     

State primary standard for the unit of electric field strength in the frequency range 0.0003–1000 MHz

The metrological investigation of the new measurement standard complex is described. The primary standard is used for reproducing and transmitting the unit of electric field strength to secondary standards and measuring instruments.Translated from Izmeritel'naya Tekhnika. No. 1, pp. 4–7, January, 1995.     

Primary state standard of the unit of inductance — The henry

Conclusions The standard of the henry is the first (with respect to its approval) state standard in the range of inductance, capacitance, and resistance measurements.This standard served up to the beginning of the sixties as the only initial (computed) quantity, on whose basis the VNIIM determined by indirect means the absolute values of the units of capacitance and resistance. The error of these indirect methods for reproducing units was of the order of 10^–5.Investigations, including circulatory international comparisons, of working standards have shown that the precision and accuracy of reproducing inductance units in the USSR are at the level of the best results obtained in national metrological institutes.In recent years new, more precise methods for reproducing resistance units have appeared. These methods, as well as the application of new types of measuring equipment, made it possible to extend substantially the nominal values' range of inductance standards covered by the test schematic.In order to ensure uniformity in this field of measurements, it is necessary to have a set of mutually-related computed inductance and capacitance standards (Fig. 3).The State Committee of standards attached to the USSR Council of Ministers approved, in accordance with the VNIIM recommendations, the coil types PB-1, KB-1, KB-2, and KB-3 as primary state standards of the henry. Prof. Igor' Nikolaevich Krotkov,head of the VNIIM laboratory,was appointed scientific keeper of this State standard.Translated from Izmeritel'naya Tekhnika, No. 10, pp. 7–11, October, 1972.     

Standard Stand for Determining the Metrological Characteristics of Resistance Strain Gages

A standard stand has been developed to normalize the metrological characteristics of resistance strain gages and certify them. The stand consists of a unit for reproducing strains and an automated system for measuring, analyzing, and recording data.     

A technique of calculating permissible errors in industrial optical pyrometers

Summary The specified permissible error of industrial optical pyrometers must be determined as the sum the absolute values of the limiting manufacturing error of the instrument and twice the root mean square value of the error due to inaccuracies in reproducing the International Temperature Scale by means of a standard radiator used for calibration.     

A laser deformometer applied to seismic detector metrological characteristics

A set of standard equipments is considered for reproducing seismic oscillation parameters that have been developed at the Mendeleev All-Union Metrology Research Institute.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 36–38, August, 1993.     

Production of the unit of capacitance

Conclusion The perfection of the complex of measuring means that are presently a state primary standard of the farad of the USSR have as their purpose a further decrease in the error of reproducing the farad, which must be decreased and brought to between 1·10^–7 and 2·10^–7. An important role, namely the perfection of indirect methods and an increase in the precision of reproducing still other electromagnetic units, was assigned to the primary standard of the unit of capacitance in the course of perfecting the system of standards of units of electrical magnitudes [4], These units include resistance, inductance, magnetic flux, and magnetic induction, whose reproduction error in the new system of standards will be decreased to between one-third and one-half.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 76–78, April, 1976.