The use of information systems is an integral part of the activities of all federal executive authorities. At the same time, in the conditions of digital transformation the fulfillment of some functions of federal executive bodies is impossible without interaction of their information systems, which often occurs as a result of information exchange (requests and answers to them). The main directions of development of information interaction of state information systems of federal executive authorities, participating to some extent in ensuring the uniformity of measurements, are given. The approaches to the organization of interaction are described, as well as the tasks that can be solved through such interaction of state information systems. On the example of interaction of the subsystem “ARSHIN” of the Federal State Information System of Rosstandart with the State Information System of housing and communal services the tasks aimed at ensuring the reliability of transferred data contained in these information systems are considered. Transition to machine-readable formats of documents in the field of measurement uniformity assurance is proposed. The conditions necessary to ensure interaction of information systems are described.

Various existing methods of verification hopper scales are analyzed, including the classical method using weights and alternative methods such as the substitution method and the element-by-element verification method. The analysis revealed the shortcomings of existing methods, as well as difficulties in their application. The main problem of verification heavy-duty scales is the need to manipulate a large number of weights (loading, unloading, storage, transportation, etc.). In most cases, checking hopper scales is generally impossible. In this regard, the task of metrological support of hopper scales has been set and solved. A force method for verification hopper scales has been developed and described. The force method is based on comparing the verifiable scales with the standard of force of the 1st discharge using a comparator. A weight-measuring or force-measuring load cell is used as a comparator. The methods and means of implementing the proposed method of verification hopper scales, as well as the results of testing, proving the possibility of its application and verification of hopper scales using force standards, are presented. On the basis of the force method, a method for verifying the WB CONUS scales using TVS comparators has been developed. The developed method makes it possible to significantly reduce the complexity, time and cost of verification. This is especially true in the production of various materials for which accurate component weighing is critical. The introduction of the force verification method can significantly improve the metrological support for measurements of large masses on scales.

The future space experiment «Sun-Terahertz» is aimed at studying the Sun in the unexplored terahertz range, obtaining new data on the terahertz radiation of the Sun, solar active regions and solar flares. The scientific equipment being developed is a set of eight detectors sensitive to radiation of various frequencies in the range 0.4–12.0 THz. The Golay cell optoacoustic receiver was used as a sensitive element of the detectors. This paper examines the problem of changing the sensitivity of receivers of this type when their own temperature changes (temperature effect). Using a test bench based on a single-channel model of scientific equipment and a black body simulator, the linear section of the temperature dependence of the receiver was determined. A method for compensating the temperature effect of optoacoustic converters Golay cell has been developed and the results of its testing on a test bench are presented. This technique will be useful in the development of scientific equipment based on Golay cells, the operation of which is expected under conditions of temperature changes in the surrounding space.

One of the important tasks of improving the International Temperature Scale ITS-90 is considered – the substitution of the fixed point of mercury (Hg) in connection with the ratification of the Minamata Convention and restrictions on the extraction, use and transportation of mercury. Reported results of experimental calibration of long-stem standard platinum resistance thermometers using a new calibration point from the list of secondary fixed points of the International Temperature Scale ITS-90. A method has been developed to realize the triple point of carbon dioxide (CO2) using liquid nitrogen. The method reduced the preparation time of the cell from 60 to 30 minutes and increased the duration of melting plateau from 10 to 40 hours. Presented results of two calibrations cases: using the fixed-point of Hg; using the triple point of CO2 instead of fixed-point Hg. Described methods to evaluate propagation of calibration uncertainty based on the fixed-point sensitivity coefficients. The fixed-points sensitivity coefficients for two subranges of standard platinum resistance thermometers calibration are analyzed and it is shown that the calibration uncertainty using the triple point of CO2 is reduced by half in the range of –189.3442...+ 0.01 °C and by 1.5 times in the range of –60...+ 60 °C. The results confirm the possibility and prospects of using the CO2 triple point as a new calibration point to substitute the fixed-point Hg.

The standard platinum resistance thermometer is currently the most accurate contact temperature sensor. One of the most important characteristics of its error is the instability of resistance during the interval between calibrations. In this work, the task was set to analyze the data from periodic calibration of 27 thermometers performed at the D. I. Mendeleev Institute for metrology for several years. Based on the analysis, it was concluded that the instability of the resistance of thermometers at the triple point of water for most thermometers exceeds ±0.002 °C, sometimes reaching several hundredths of a degree. The work analyzes the reasons for the instability of resistance, as well as the instability of the relative resistance of thermometers. Based on data analysis of the thermometer error at the temperatures between calibration points and graphs of changes in the interpolation function during the interval between the calibrations in the entire measurement range, it was shown that the error associated with the instability of the thermometer can be reduced from hundredths to thousandths of a degree when used as a measured parameter relative resistance of the thermometer. It is proposed to include in the regulatory documents on the verification methods of Standard platinum resistance thermometers an additional periodic calibration of the thermometers at the triple point of water.

Today, there is great scientific interest in the possibility of implementing reference sources of low currents based on single-electron pumps using the single-electron tunneling effect and the modern definition of the SI system. However, the practical use of this effect in everyday metrological practice has not yet reached the stage of widespread use. Typically, for routine calibration work in laboratories, either mass-produced instruments (low current sources and meters, electrometers) are used, which are calibrated against higher standards, or specially designed precision current sources. The article describes a reference installation developed on the basis of the VNIIFTRI, where in the mode of generating ultralow currents the principle of forming a linearly increasing voltage on a reference capacitor is used. A simplified block diagram of the reference setup is shown. Issues of practical adjustment of modern electrometers are considered. The generalized results of participation in international comparisons on low currents EURAMET.EM-S44 “Comparison of ultra-low DC current sources” conducted by national metrological institutes in 2018–2020 are presented. The results of a metrological study of the calibration factor Q and an example of calculating the uncertainty budget of measurements carried out at the VNIIFTRI as part of these international comparisons are presented. The research described in the article to increase the accuracy of measurements of small and ultra-low currents of this level has valuable practical significance in the field of electrical measurements, in aeroionometry and metrology of ionizing radiation.

The problem of reconstructing the distribution of permittivity and magnetic permeability over the thickness (profile) of non-metallic coatings is relevant in connection with the increasing role of modern methods of radio wave non-destructive testing for assessing the quality of various types of materials and products. Using radio wave methods, the distribution of permittivity and magnetic permeability over layers of multilayer dielectric and magnetodielectric coatings on a metal substrate was reconstructed. The resolution of the method of surface electromagnetic waves in terms of permittivity and magnetic permeability has been studied – the difference between the values of the permittivity and magnetic permeability of adjacent layers of multilayer dielectric and magnetodielectric coatings, respectively. An original method has been developed for assessing the maximum resolution of the surface electromagnetic wave method depending on the electrophysical parameters of the coating layers, the number and bandwidth of measurements, as well as the standard deviation of noise affecting the result of measuring the field attenuation coefficients of the surface wave. The structure of the measuring complex that implements the developed methodology is given. The results of numerical and full-scale experiments to assess the resolution limits of the permittivity and magnetic permeability of layers of two-layer coatings of various types are presented. Numerical experiments were carried out on a sample of a twolayer radio-absorbing coating, and full-scale experiments were carried out on a sample of a two-layer dielectric coating based on Ro4003C and Arlon25N materials. The results of numerical and natural experiments were found to coincide, which confirms the adequacy of the developed methodology. With a measurement bandwidth of 9.0–12.5 GHz and a standard noise deviation of 0.002, the resolution limit for the permittivity and magnetic permeability of layers is 0.25–0.50 %. The proposed technique can be in demand in various science-intensive fields when assessing the electrical parameters of multilayer coatings during efficiency tests.

The problem of satisfying the needs of the domestic market of the Russian Federation for creating domestic particle size standard reference materials in liquids to ensure uniformity in measurements of the granulometric composition of aerosols and powdery substances is considered. It is known that, under various conditions, monodisperse suspensions of polystyrene latex spheres can be synthesized, both monodisperse and polydisperse samples being obtainable. The effect of the composition and solubility of surfactants in a styrene-based water emulsion on the particle size of suspensions obtained as a result of emulsion polymerization, and their polydispersity, has been investigated. The metrological characteristics of polystyrene suspensions based on sodium, potassium, and lithium laureths synthesized in this study were determined using dynamic light scattering and laser diffraction techniques. It has been found that the size and degree of polydispersity of particles in suspensions based on lauric acid salts is primarily influenced by the solubility of the surfactant and the surface tension of the interfacial layer formed between styrene and water at the time of particle formation. The effect of the rate of reaction, as well as the concentration of surfactants, on the size and polydispersity of the synthesized particles, has been studied. It has been found that when potassium persulfate is used as the initiator in the reaction, particle size distributions are monodisperse for suspensions based on sodium or potassium laureate. The polydispersity degree of lithium laureate-based suspensions is approximately 1.5 to 2 times higher compared to other suspension samples. When azoisobutyronitrile is used as an initiator, all suspensions samples are monodisperse. It has been experimentally determined that the achievement of monodisperse samples is due to the polymer-monomer particle formation time, which is comparable to the monomer transformation rate. The results obtained will be utilized in the development and establishment of particle size standard reference materials for storage and reproduction of particle size values within a liquid medium.

Indicators of the accuracy of measurements of the most important characteristics of the structure of porous and dispersed materials - specific adsorption of gases, specific surface area, specific pore volume and pore size – are considered. The performance of sorbents, catalysts and membranes in the chemical and petroleum industries, including the purification of substances and materials, depends on the values of these characteristics. It has been established that for mutual recognition of national standards and certificates of calibrations and measurements of porosity characteristics of solid substances performed by national metrological institutes, it is required to organize and successfully participate in three international key comparisons under the auspices of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology of the International Bureau of Weights and Measures. The results of the participation of national metrology institutes and designated organizations of Germany, China, Japan, Brazil, Turkey and Russia in three international key comparisons in the field of measurements of specific adsorption of gases (nitrogen, argon, krypton) and specific surface area of solids (zeolite, silicon oxides and aluminum) are presented. Carrying out the optimal number of comparisons makes it possible to register in the Key Comparison Database of the International Bureau of Weights and Measures the measuring and calibration capabilities of the national metrological institutes of the participating countries for various matrices in a wide range of measurements of specific adsorption of gases 0.001–25 mol/kg and specific surface area of solids 0.1–1500 m2/g. Based on the results of these three international key comparisons, 18 of broad calibration and measurement capabilities of the Russian participant, the D. I. Mendeleev Institute for Metrology, were entered into the Key Comparison Database; two of these items are currently undergoing examination, including reference materials produced by this institute. A comparative analysis of the results of measurements of the specific surface area of solids using nitrogen and krypton as adsorbates was performed. It has been established that the uncertainty of the measurement results of the specific surface area is significantly less in the case of using krypton as an adsorbate with a specific surface area of less than 1 m2/g, which is due to the higher values of the relative pressure of krypton compared to nitrogen. The use of calibration and testing laboratories in Russia of certified reference materials of sorption properties presented in the Key Comparison Database of the International Bureau of Weights and Measures will ensure metrological traceability in the field of measurements of porosity characteristics.