The paper describes the creation of the new State standard of thermal capacity of solids. The main point of the project is the design of the high accuracy adiabatic calorimeter КА-С4. The construction and the modes of operation of installation are presented. The sources of uncertainty and the resulting values of accuracy are analyzed. Also the paper contains the information about the measures for the transmitting of the unit to the devices of lower accuracy.

The authors analyze the factors affecting the errors in the estimates of the correlation functions of the noisy signals when using traditional calculation algorithms. It is shown that the sum noise of the noisy signal in many cases consists of the noise caused by external factors and the noise caused by the initiation of various defects during the operation of control objects. For this reason, in order to eliminate the error in the results of the correlation analysis of noisy signals, it is necessary to create algorithms and technologies for determining the estimate of the noise variance and the cross-correlation functions between the useful signal and the noise. For this purpose, appropriate algorithms and technologies are proposed that open up the possibility of reducing the error of traditional technologies for determining the estimates of correlation functions. With the purpose of reducing the error of the results of correlation analysis, a technology is proposed for determining the approximate equivalent samples of the noise of the noisy signals. It is shown that using the equivalent noise samples, it is possible to obtain results that are identical to the results of using real samples of the noise in the correlation analysis of the same signals. Moreover, by extracting the equivalent noise samples from the noisy signal, the equivalent samples of the useful signal are also determined, which allow determining the estimates equivalent to the estimates of the correlation functions of the useful signal. At the same time, having equivalent noise samples and useful signal samples, the estimates of the cross-correlation function between the useful signal and the noise are determined. The study have shown that despite certain errors in the equivalent samples compared to the true samples, with a sufficient observation time using equivalent samples, the error of traditional technologies for the correlation analysis of noisy signals can be significantly reduced. These technologies can also be used to correct errors in the results of the analysis of experimental data in information-measuring and other measuring complexes and systems, which will significantly improve their metrological characteristics.

A method is proposed for transferring a unit of laser radiation power to power measuring instruments of kilowatt levels with the possibility of constant monitoring of the transmission process. A measuring optical laser power divider has been developed, which is structurally made in the form of a wedge and allows one to determine the radiation power of the beam delivered to the calibrated measuring instrument using the relatively small radiation power reflected from the enlightened surface of the front edge of the wedge. The proposed method is based on the application of the developed divider in the reference installation and provides for the implementation of three modes of operation of the installation: the mode of determining the equivalence coefficient; the mode of determining the division ratio of the optical divider; transmission mode of a power unit to measuring instruments and determination of a control parameter of an optical divider. The control of the transmission process is carried out by measuring the radiation power reflected from the rear edge of the wedge, and determining the control parameter. The conditions are given under which it is advisable to use the proposed mode for determining the division coefficient of the optical divider. A feature of the method under consideration is the possibility of operational control of the division coefficient of the optical divider, which allows real-time assessment of the accuracy of the calibration process of measuring instruments. The formula of metrological traceability of the results of power measurements to GET 28-2016 is obtained. The main components of the error in determining the radiation power supplied to the input of a calibrated measuring instrument are considered. The results of experimental studies of the method suggest that at a wavelength of 10,6 μm, the total error of power measurement, expressed as the standard deviation, does not exceed 2,0 %. The method can be used in the corresponding secondary power unit standards that receive a unit from the State Special Standard for Average Power GET 28-2016.

Currently, communication systems are widely used, where optical fiber is used as a transmission medium. In turn, decision and control of optical fiber parameters has become needfull, since these parameters have a significant impact on the quality and quantity of transmitted information using fiber-optic communication systems. One of these parameters is cut-off wavelength of the single-mode optical fiber, which determines the minimum wavelength of optical radiation at which the optical fiber supports only one propagated mode, in other words, operates in single-mode. The problem of decision cut-off wavelength of the optical fiber used in fiber-optic communication systems is quite relevant and demand, since when the optical fiber operates in multimode, its throughput decreases due to inter-mode dispersion. The article describes methods for measuring cut-off wavelength of the optical fiber. Variant of a highprecision apparatus for measuring cut-off wavelength of the optical fiber has been proposed and tested. The measurements were performed based on the reference bending technique described in GOST R IEC 60793-1-44-2013. The analysis of the accuracy characteristics of the developed apparatus is made, a quantitative assessment of the measurement error is obtained.

Problems requiring high-precision comparisons and synchronization of time scales of remote time and frequency standards are considered. The prospects of using fiber-optic communication lines to solve these problems are considered. Data on maximum operating distances and accuracy characteristics of time scale comparison systems using fiber-optic communication lines are given. It is shown that the range of existing systems is not enough to solve a number of problems. A method for amplifying optical signals in an optical fiber using the effect of stimulated Raman scattering is considered. The application of the Raman amplifier in telecommunication systems is considered. A method is proposed for using the effect of stimulated Raman scattering (SRS) to amplify the optical signals of time scale comparison systems. A scheme is proposed for a system of one- and two-way comparisons of time scales of distant objects, using signal amplification based on the SRS effect realized using two-way counter-pumping. The principle of the system’s operation and the procedure for determining the divergence in the time scales of remote objects are described. The results of estimation of the error and range of systems of one- and two-way comparisons of time scales using Raman amplifier are presented. It is shown that the implementation of Raman-amplifi cation in the equipment of such systems will allow more than three times to increase their range without reducing the accuracy of the systems.

This paper suggests the verification and calibration method of thermal imagers that consists in comparison of temperature readings obtained by contact and thermal imaging method. The experimental setup has been developed to confirm the reliability of the proposed method. The main element of experimental setup is an emitting surface in the form of rectangular plate that measures 330×200×4 mm. The plate is covered with paint which emissivity factor is not less than 0,96. The paper presents the results of temperature field calculations on the plate emitting surface. The temperature field of the plate emitting surface has been determined by the contact method using chromel-alumel thermocouples and thermal imaging method. As a result of the obtained temperature values analysis, it has been concluded that if the plate emitting surface temperatures close to 50 °C, the heat exchange of the plate with the ambient air plays a significant role. The air heaters are applied in order to reduce the heat flows dissipation from the plate emitting surface into the environment. The heaters are two aluminum-magnesium alloy plates attached to the end face of the emitting surface. The metal heat exchangers – coils are installed on the surfaces of the plates and connected by hoses to the liquid thermostat. One of the plates heats the air flowing around the emitting surface, and another one prevents the emission thermal expansion into the environment. As a result of heaters application, the heat exchange intensity of a plate radiating surface with environment decreases. Moreover, recommendations about the choice of heaters sizes have been given. The main advantages of the method proposed are the following: ensuring high isothermic of the emitting surface throughout the height of the plate; accuracy of the temperature maintaining at a given level; reducing the device transition time to steady-state regime.

The problems of ensuring the stability of the temperature of the chromatographic experiment carried out using a serial gas chromatograph LGH-3000 are considered. Limiting the permissible heating rate of the chromatograph thermostats does not allow a quick transition to the new conditions of the chromatographic experiment in accordance with the requirements of the technical conditions. The processes of heating and cooling the thermostat are analyzed. It is shown that the ratio of the duration of the interval equal to the sum of the durations of the heating and cooling intervals to the duration of the heating interval is inversely proportional to the temperature of the chromatographic experiment. Based on this situation, an empirical algorithm is proposed for heating the thermostat to a given temperature, which made it possible to reduce the time it takes to reach a given temperature in the entire range of operating temperatures.

Paper studies the problems about experimental determining magnetic parameters of nonuniform granular magnetics. It has been noted that the existing shortage of direct and (or) indirect experimental data on the magnetic properties of granular ferromagnetic specimens with different values of a relative length, in particular, has a negative impact on the validity of the requirements and decisions to create and ensure the performance of relevant functional elements, movable operating elements of various equipments and devices. By the example of cylindrical specimens of balls with the range of relative length 1–16 within the framework of effective medium macromodel the dependences of induction, magnetic permeability, susceptibility, magnetization and field intensity have been obtained. It has been shown that in the range of field intensity 9–47 kA/m values of induction and magnetization of investigating specimens increase, that indicates the absence of magnetic saturation of such granular (as opposed to solid) magnetics. And this is the case at almost stable values of magnetic susceptibility and permeability. Obtained results are useful in designing movable operating elements of various equipments and devices.

The article considers problems of modern global navigation satellite systems high-precision user terminals performance in jamming and spoofing environment. The solution to the low interference resistance problem is the use of digital antenna arrays with spatiotemporal signal processing algorithms. The well-known, most studied and brought to practice algorithms for the spatiotemporal signal processing are described, reasons that do not allow the use of these algorithms in global navigation satellite systems high-precision user terminals are given. This article proposes a spatiotemporal signal processing algorithm based on a spatiotemporal filter of finite length with a special, theoretically justified requirement for the Hermitian symmetry of the matrix impulse response, which guarantees the absence of signal distortion in any interference environment. In this case, the spatiotemporal filter impulse response is calculated by the criterion of optimal interference suppression. The proposed spatiotemporal filter characteristics, as well as other spatiotemporal signal processing algorithms characteristics, were studied by mathematical simulation with random enumeration of interference environment parameters (directions to signals, to numerous interferences and their reflections, range of interference reflectors, reflection phases, interference and reflections levels, etc.). Simulation results are presented in the form of distribution functions of signal-to-noise ratios at the output of spatiotemporal signal processing algorithms and distribution functions of phase and signal time biases. The obtained dependencies confirm the absence of phase and signal time biases in the spatiotemporal filter in absolutely any interference environment with interfering multipath, while the spatiotemporal filter provides greater interference resistance than compensating spatiotemporal signal processing algorithms.

Information is provided on a standard facility for calibrating hydrophones at frequencies from 100 kHz to 3 MHz, which created to expand the frequency range of the State primary standard GET 55-2017 to the area of high-frequency ultrasound. The actuality of the standard facility creation is justified. The possibilities of measurements and operation principles of the facility are briefly y reviewed. The requirements to the characteristics of ultrasonic transducers are discussed. When selecting standard transducers, priority was given to their temporal stability, since the unevenness of the transducer frequency response is not of fundamental importance when calibrating using a tone signal. To reduce the influence of directivity, a precision four-coordinate positioning system of transducers applies, which including the control of transducers mutual position using laser beam. Attention is paid to the problems related with the mastering of higher frequencies.

Certified reference materials (CRM) composed of propyl (11383-2019) and isopropyl (11384-2019) alcohols solutions were created for validation of measurement procedures and control of measurement errors of measurement results of mass concentrations of toxic substances (alcohol) in biological objects (urine, blood) and water. Two ways of establishing the value of the certified characteristic – mass consentration of propanol-1 or propanol-2 have been studied. The results obtained by the preparation procedure and comparison with the standard are the same within the margin of error.