Need and relevance of precise thermal conductivity measurements of solid materials used in heat insulating and heat exchange systems is shown originating from significant dependence of heat conductivity of solid on its composition and synthesis method. Construction, operation principle and the results of metrological investigation of the State primary special Standard of the unit of thermal conductivity of solids GET 141-2020 are presented. GET 141-2020 is equipped with new cryostat and cell for thermal conductivity measurements compared to GET 141-84 used till 2020. The range of reproduction of the unit of thermal conductivity of solids has been expanded from 0,1–10 W/(m·K) to 0,05–15 W/(m·K), the temperature range in which measurements are carried out has been increased from 4,2–90 K up to 2–300 K compared to GET 141-84. Method of thermal conductivity measurements is described with application of developed cryostat. An approaches of creation of stable heat contacts between measured sample and heat plates of measurement cell are presented. Metrological characteristics of GET 141-2020 are investigated, a budget of measurement uncertainty is calculated for reproduction of the unit of thermal conductivity of solids. GET 141-2020 is used for calibration of thermal conductivity standards utilized for verification and calibration of thermal conductivity measurement equipment.

The issues of metrological support of acoustic-emission means of non-destructive testing and diagnostics designed to improve the accuracy and reliability of control results in the system of ensuring safe and trouble-free operation of equipment at hazardous production facilities and structures are investigated. The purpose of the work is to ensure the unity of acoustic measurements in solid bodies. The composition of the State Primary Standard of units of the amplitude of ultrasonic displacement, the vibrational velocity of the surface of solid media and the electroacoustic conversion coefficient GET 194-2022 is presented. The reference installation “Coefficient” developed on the basis of the laser interferometry measurement method and included in GET 194-2022 for reproducing units of the electroacoustic conversion coefficient is described, the principle of its operation is described. Metrological characteristics of GET 194-2022 are given. The scope of application of the standard during its implementation is indicated: scientific and technical support for the unity and required accuracy of acoustic measurements in solid media, increasing the reliability of their results; reducing the risk of man-made accidents; metrological assurance of hygienic requirements when working with sources of “contact ultrasound” on surfaces in contact with the operator's hands.

The composition of the State primary standard of hydrogen ions in aqueous solutions GET 54-2019 is presented. The standard includes measures of acidity and a coulometric installation device, the measurement range of the hydrogen index is from 0.01 to 12.00. The applied methods and reproducing the values of the hydrogen index GET 54-2019 allowed to reduce the total standard uncertainty to 0.0012, which corresponds to the world best analogues of pH standards. The metrological characteristics of GET 54-2019 and the results of international key comparisons to determine the hydrogen index of borate buff er solution CCQM-K19.2018 are presented. The State primary pH standard GET 54-2019 is used in many industries, science and technology, a special place for pH measurement is in the chemical, pharmaceutical and food industries, where it is very important to control the hydrogen index at all stages of the production cycle. Recently, the control pollution of water bodies by human waste has increased, so pH measurements have become in environmental monitoring. The improvement of the GET 54-2019 allowed to expand its scope by increasing the range of measurements of the hydrogen index in the highly acidic region. It has become possible to increase the accuracy of measurements in studies of the acidity of the human gastrointestinal tract, which reduces the risk of making an incorrect diagnosis.

The principle of the geometrical-dimensional representation of physical quantities in system SI dimensions in the form of separate system cells on the LT-dimensional basis is described. Depending on the ratio of dimensions of quantities in SI and LT representations, the physical quantities are combined into separate clusters, which form the multilevel content of most system cells. The physical quantities of each cluster have nearest dimensional relations through, length, time, and velocity. The distant dimensional relations of physical quantities expressing physical regularities (without participation of numerical coefficients) have the form of selected parallelograms or selected lines (when a parallelogram looks as if in profile). The additional coefficients of cluster groups cancel each other, and the products of dimensions of physical quantities located on opposite sides of the selected parallelogram are equal to each other. This allows us not only to illustrate the known regularities, but also to discover new ones. In different  variants of the system representation of physical quantities certain properties and peculiarities in the arrangement of quantized and constant physical quantities are observed.

In the article, the methods of technological processes monitoring in the modern machine-building manufacturing are observed. The task of constructing the procedures of measurement (variable) inspection for the lots with two-parameter generalization of Rayleigh distribution of quality characteristic is set and solved. The test statistics distributions have been explored. The sufficiently accurate computational procedures for the distribution functions evaluation are described. The operating characteristics of two-parameter sampling plan and the previously constructed one-parameter plan are compared. It is shown that the same features are provided under comparable conditions with only a slight increase of the sample size. The results are applicable in acceptance sampling of lots of parts with external and internal cylindrical surfaces.

Abstract. The possibility of determining the difference in gravitational potentials and optometric heights in the Earth's field based on measurements of the phase difference of laser radiation in an optical fiber, due to the effect of the gravitational delay of light waves, is proposed and investigated. A block diagram of a measuring complex designed to measure the phase difference of light waves caused by this effect is proposed. The measurements use two coherent light waves from a single laser, each propagating along a separate fiber optic communication line. The composition of each fiber-optic communication line includes the same coils of a long optical fi beer, spaced apart in height. The analysis of the factors info fencing the phase relations of waves propagating along two communication lines of the measuring complex is carried out. The phase effects of the delay caused by the influence of the true gravitational field of the Earth, as well as the info hence of the fields of inertial forces and gyroscopic effects due to the rotation of the Earth are determined. Ways to suppress the effects that introduce measurement errors are proposed. The achievable errors in measuring the diff Terence in gravitational potentials and the corresponding diff Terence in optometric heights are estimated. With a fi err length in coils of 100 km and a height diff Terence of 100 m; these errors are 0.2 m2/s2 and 2 cm, respectively. It is proposed to call the measuring complex under study a laser gravipotentiometer. It is an optical analogue of the well-known radio-frequency quantum level, but does not require ultra-stable frequency and time standards. The research results of the proposed measuring complex are relevant for the development and improvement of measuring instruments for the parameters of the Earth's gravitational fi eld, as well as means of high-precision synchronization of time scales of remote standards.

The problem of maintaining synchronization of the national time scale of the Russian Federation UTC(SU) with the international coordinated time scale UTC within the specified limits is considered. Methods for comparing remote time scales currently used in the work of the State Standard of Time and Frequency GET 1-2022 do not allow meeting the upcoming requirements for UTC(SU) and UTC synchronization. Forecasting the difference between UTC(SU) and UTC is currently not carried out; in practice, data from the official bulletins of the International Bureau of Weights and Measures (BIPM) are used. These data are available with a large time delay, which also makes it difficult to ensure that the national time scale is in sync with the international one. The purpose of this study is to develop methods and algorithms that will ensure the fulfillment of upcoming requirements for the limits of acceptable difference between UTC(SU) and UTC. To do this, it is necessary to solve the following tasks: the choice of a method for comparing remote time scales, the development of an algorithm for the operational automatic prediction of the discrepancy of the above time scales with a delay of no more than one day based on the chosen method of comparison. To accomplish the tasks set, software was developed that implements the proposed methods and algorithms. An analysis of the effectiveness of the developed system was also carried out based on a comparison with the estimates of the International Bureau of Weights and Measures. The scope of the results obtained is to ensure the functioning of the State Standard GET 1-2022 within the framework of the technical requirements specified for it.

Methods of increasing the accuracy of liquid level measurements are considered. The level-measuring installation UUE1r-N-20 with a direct change in the liquid level in the range of 0–20 m with a measuring system based on the XL-80 laser interferometry measuring system is presented. The principle of operation of the measuring system of the level-measuring installation is based on measuring the linear movements of the flu oat in the liquid relative to the zero reference point of the level measuring installation. A mathematical model is given for determining the liquid level using a level-measuring installation, taking into account the info hence of environmental parameters on the elements of the measuring system. The metrological characteristics of the level-measuring installation, including the uncertainty of liquid level measurements, are calculated. The confidence limits of the total measurement error of a liquid level unit with a confidence probability of 0.95 are ±0.11 mm when transferring a liquid level unit to standards or liquid level measuring instruments with a fixed zero reference point and ±0.044 mm when transferring a liquid level unit to standards or liquid level measuring instruments that do not have a fixed zero reference point.

The main element of the reference field-forming system of the State primary standard of the unit of electric field strength in the frequency range from 0 to 20 kHz GET 158-2020 is a reference converter consisting of a shielded capacitor with flat round plates and additional electrodes connected to an AC or DC voltage source. Due to the approval of the standard in the specified composition and the change in the power supply scheme of the reference field-forming system from symmetric to symmetrical, the maximum value of the voltage reproduced by the standard has been increased from 2000 to 4000 V/m and the accuracy of its reproduction and transmission has been increased. For the case of symmetrical power supply, it was necessary to derive a measurement equation linking the reproducible value and the input parameters of the reference converter (voltage, geometric dimensions). The derivation of the measurement equation of a reference converter excited by a symmetric voltage is presented, obtained as a result of solving an electrostatic problem with symmetric boundary conditions for the potential of the electrodes. Optimal values of the voltages applied to the additional electrodes are found in order to obtain maximum uniformity of the electric field in the area of the center of the converter. It is shown that the inhomogeneity of the field for a specific implementation of a shielded capacitor is no more than 0.1 %. The results obtained can be used in the fi eld of metrology of constant and variable electric fields in the development of reference sources of electric field and working standards.

A brief overview of the standards required for the serial production of LAN cables of various categories is given. It is shown that for twisted pairs LAN cables of categories 5e and higher, it is necessary to finalize the procedure for measuring key frequency characteristics (in particular, determining the frequency dependence of the actual value of the wave resistance), regulated by the current GOST R 54429-2011 “Symmetrical pair communication cables for digital transmission systems. General technical specification”. The reason for the errors of network analyzers – the influence of an extended cutting section – is revealed, and the hypothesis that it is impossible to eliminate it within the framework of existing models is substantiated. A hypothesis is formulated about the interference of signals reflected from the beginning of the twisted pair and from the place of its entry into the shell as the main cause of distortion of the results of practical measurements. Experimental data confirming the correctness of the proposed assumptions are presented. The modernization of the calibration procedure of the measuring system is proposed without updating the hardware and software of the vector circuit analyzer. The desired result is achieved by using a distributed calibration load, individual for each type of cable, based on a segment of a twisted pair, which is manufactured in a production laboratory. Using calculated data and measurement results, it is shown that the use of such a load reduces from 14 to 3 % the methodological error in measuring the impedance of widespread category 5e cables. The results obtained are invariant to the type of measuring system and can be used in the production testing of modern LAN cables of high categories.

This article considers the features of developing pharmaceutical substances reference materials using the example of thiamine hydrochloride. It describes the developing procedure for reference materials: preliminary authentication of main substance of a certified pharmaceutical substance, determination of the mass fraction of main substance by direct (titrimetry) and indirect (mass balance) methods, verification of the feasibility of methods for assessing all impurities, provision of the traceability of certified value. The results of infrared Fourier spectrometry confirm the authenticity of the analyzed substance of thiamine hydrochloride. The measurements of mass fraction of main substance was carried out using acid-base titration in aqueous-alcoholic medium, as well as mass balance method, taking into account the content of sulfate ash, water, related impurities, and residual organic solvents. The expanded uncertainty of measurement results of the mass fraction of main substance and groups of impurities was evaluated by constructing a full uncertainty budget. It has been established that the measurements results of the mass fraction of main substance in the substance of thiamine hydrochloride, obtained by a titrimetric method (97.36±0.40) % and a mass balance method (97.37±0.08) %, are consistent with each other within the stated uncertainties. The metrological traceability of the certified value of reference material to the units of quantities reproduced by state primary measurement standards (State primary measurement standard for unit of mass GET 3-2020, State primary measurement standard for units of mass fraction and mass (molar) concentration of water in liquid and firm substances and materials GET 173-2017, State primary measurement standard for units of mass (molar, atomic) fraction and mass (molar) concentration of components in liquid and solid substances and materials based on coulometry GET 176-2019, State primary measurement standard for units of mass (molar) fraction and mass (molar) concentration of organic components in liquid and solid substances and materials based on liquid and gas chromatography-mass spectrometry with isotope dilution and gravimetry GET 208-2019) was ensured. The results are relevant for ensuring the uniformity of measurements in the quality control of medicines.

Various methods of measuring the moisture content of bulk materials (grain and grain products) used at grain processing enterprises are described, including a method using such an indicator of grain quality as the mass humidity ratio. It is shown that it is preferable to use the method of ultrahigh frequency humidity measurement. A functional diagram of an installation for measuring humidity, grain moisture and grain products in the technological process by the ultrahigh frequency method is presented. The info hence of grain heterogeneity in density on the informative parameter of humidity with an ultrahigh-frequency method of measuring humidity is analyzed, considering the complexity of mathematical modeling of humidity control in the technological process of grain materials production. The results of experimental measurements of humidity in laboratory and production conditions of a grain processing enterprise are presented, an analysis of measurement errors is presented. It is shown that the most signify cant contribution in amplitude measurements is made by the unevenness of the moisture distribution in the bond forms and the inhomogeneity of the sample in density, and in phase measurements – a change in density, and the error in measuring humidity decreases with increasing volume density. Based on a comparative analysis of grain moisture measurement errors, it was found that the use of the multiparametric method reduces the specified error compared to the error of the one-parameter method, which is explained by minimizing the info hence of various interfering factors. The expediency of using a multipara metric method of measuring the mass ratio of grain moisture at grain processing plants and enterprises is substantiated.