Primary standard for the number concentration of liquid-borne particles: Extension of the diameter range from the micrometer to the sub-micrometer level and reduction of the measurement uncertainty

Metrologia ◽  
2021 ◽  
Author(s):  
Yuki Kuruma ◽  
Taka Sakaguchi ◽  
Hiromu Sakurai
2020 ◽  
pp. 6-10
Author(s):  
A.E. Aslanyan ◽  
E.G. Aslanyan ◽  
S.M. Gavrilkin ◽  
A.S. Doynikov ◽  
A.N. Shchipunov

The article presents the results of studies to improve the National primary standard machine for hardness of metals on the shore D scale GET 161-2001, which were performed in FSUE “VNIIFTRI” from 2016 to 2018 in accordance with the technical task of Rosstandart.The improvement was carried out in order to ensure the uniformity of hardness measurements on the Leeb scales. The created new parts of the primary standard machine, which are settings for reproducing hardness numbers on the Leeb scales, are considered. Metrological characteristics of the upgraded and adopted National primary standard machine (GET 161-2019) were investigated, the budget of measurement uncertainty was calculated for reproducing hardness numbers on the Leeb scales.


Author(s):  
Mohamed Hamdy ◽  
Mohamed A. Bayoumi ◽  
Ali E. Abuelezz ◽  
Alaaeldin A. Eltawil

This paper presents a developed design and construction to improve the performance and increasing the density measuring capability of the previous Hydrostatic Weighing Apparatus (HWA-NIS) at the National Institute of Standards (NIS) up to 20 kg. The previous (HWA-NIS) has been constructed up to 10 kg on 2014. The 2-Positions mass handler in the previous (HWA) was developed with 4-Positions pentagon shape to be able to make handling for individual masses in a group at once, when transferring the traceability from the primary standard “the Silicon Sphere” to the standard masses in the density scale weighing process. The weighing pan in the previous (HWA) was developed with four suspension wires with a diameter of 0.3 mm each, leads to reduce the surface tension affect on the measurement uncertainty by factor four times. The density of the standard masses in the range from 2 kg up to 20 kg were measured with an improved expanded uncertainty from 0.150 kg/m3 to 0.078 kg/m3 respectively due to reducing the effect of surface tension via the developed design of the weighing pan.


2015 ◽  
Vol 9 (5) ◽  
pp. 502-507
Author(s):  
Zi Xue ◽  
◽  
Yao Huang ◽  
Heyan Wang ◽  
Hu Lin

At the National Institute of Metrology (NIM), China, the Small Angle Measuring System, which is based on the sine principle, was developed as the national primary standard for the plane angle in an angular measuring range of ±5°. The measurement uncertainty of this system is dominated by the accuracy of an invar angular interferometer optical system. To calibrate this angle interferometer system, a series of known reference standards were generated with a multi-step method using a double-deck rotary table. The measurement uncertainty of the calibration is estimated to be approximately 0.05'' (k=2).


1968 ◽  
Vol 19 (03/04) ◽  
pp. 423-429 ◽  
Author(s):  
G. M Thelin ◽  

SummaryA stable, lyophilized AHF reference plasma has been prepared from pooled plasma from at least 50 normal healthy donors and standardized against a primary standard of fresh plasma from 20 healthy male donors aged 20 to 40. Average AHF potency of a typical lot is 98.8%, and moisture content is less than 0.5%. Under storage at -25° C, this AHF reference plasma is stable for at least 18 months. It has been used in several major coagulation laboratories, and has given consistently satisfactory and reproducible results in AHF assays.


2020 ◽  
pp. 8-12
Author(s):  
Alexandr V. Oborin ◽  
Anna Y. Villevalde ◽  
Sergey G. Trofimchuk

The results of development of the national primary standard of air kerma, air kerma rate, exposure, exposure rate and energy flux for X-rays and gamma radiation GET 8-2011 in 2019 are presented according to the recommendations of the ICRU Report No. 90 “Key Data for Ionizing-Radiation Dosimetry: Measurement Standards and Applications”. The following changes are made to the equations for the units determination with the standard: in the field of X-rays, new correction coefficients of the free-air ionization chambers are introduced and the relative standard uncertainty of the average energy to create an ion pair in air is changed; in the field of gamma radiation, the product of the average energy to create an ion pair in air and the electron stopping-power graphite to air ratio for the cavity ionization chambers is changed. More accurate values of the units reproduced by GET 8-2019 are obtained and new metrological characteristics of the standard are stated.


2020 ◽  
pp. 3-7
Author(s):  
Vladlen Ya. Shifrin ◽  
Denis I. Belyakov ◽  
Alexander E. Shilov ◽  
Denis D. Kosenko

The results of works aimed at increasing the level of uniformity of measurements of the magnetic induction of a constant field – the basic value in the field of magnetic measurements. A set of equipment for reproducing a unit of magnetic induction of a constant field in the range of 1–25 mT was created and described. The inclusion of this complex in the State primary standard of units of magnetic induction, magnetic flux, magnetic moment and magnetic induction gradient GET 12-2011 will ensure the reproduction and direct transmission of the unit of permanent magnetic induction in the ranges of not only weak (10–3–1 mT), but medium (1–25 mT) and strong (0.025–1 T) magnetic fields. A quantum cesium magnetometer based on the resolved structure of cesium atoms was created to transmit the unit of magnetic induction to the region of medium fields. The procedure for calculating the frequency conversion coefficients to magnetic induction of the created quantum cesium magnetometer is described. The uncertainty budget for reproducing a unit of magnetic induction of a constant field using the created complex is estimated.


2020 ◽  
pp. 59-63
Author(s):  
A.S. Bondarenko ◽  
A.S. Borovkov ◽  
I.M. Malay ◽  
V.A. Semyonov

The analysis of the current state of the reflection coefficient measurements in waveguides at millimeter waves is carried out. An approach for solving the problem of reproducing the reflection coefficient measurement scale is proposed. Mathematical equations, which are the basis of the reflection coefficient measurement equation are obtained. The method of determining the metrological performance of reflection coefficient unit’s reference standards is developed. The results of electrodynamic modeling and analytical calculations by the developed method are compared. It is shown that this method can be used for reproducing the reflection coefficient unit in the development of the State primary standard.


2020 ◽  
pp. 53-58
Author(s):  
A. V. Koudelny ◽  
I. M. Malay ◽  
V. A. Perepelkin ◽  
I. P. Chirkov

The possibility of using bolometric converters of microwave power from the State primary standard of the unit of power of electromagnetic waves in waveguide and coaxial paths GET 167-2017, which has a frequency range from 37,5 to 78,33 GHz, in an extended frequency range up to 220 GHz, is shown. Studies of semiconductor bolometric converters of microwave power in an extended frequency range have confirmed good agreement and smooth frequency characteristics of the effective efficiency factor of the converters. Based on the research results, the State working standard of the unit of power of electromagnetic waves of 0,1–10 mW in the frequency range from 37,5 to 220 GHz 3.1.ZZT.0288.2018 was approved. The technical characteristics of the working standard of the unit of power of electromagnetic oscillations in an extended frequency range from 37,5 to 220 GHz are given.


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