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The composition, principle of operation and basic metrological characteristics of the State Primary Special Standard of acceleration for gravimetry GET 190-2019 are given. The standard is the top link of the reference base for gravitational acceleration measurements. The accuracy and reliability of GET 190-2019 have been increased as a result of optimization of methods for adjusting measuring systems and the inclusion of improved systems, assemblies and modern element base in its composition. Particular attention is paid to the refinement of the corrections introduced into the measurement results due to methodological, physical and technical limitations. The applied research methods made it possible to confirm the range of GET 190-2019, as well as to determine the contributions of the main sources and the total value of the error. The metrological characteristics of GET 190-2019 are confirmed by the results of measurements of the absolute value of gravimetric acceleration at the gravimetric station Lomonosov-1 and their comparison with the data obtained at different times using high-precision foreign and domestic gravimeters. The relevance of the work is determined by the requirements of applied problems whose solution requires data on the parameters of the Earth’s gravitational field. Geophysics and navigation are the main areas of application for high precision measurements in this field.

An approach to creating reference tools for reproducing the units of volumetric activity of radon and thoron and radon flux density from the ground surface based on the physical principles of reproducing these units of quantities, and usage as hardware components of rebuilding bubblers with a radioactive solution of radium salt, reference capacities of a known amount, emanation chambers for generation of thoron, a gamma spectrometer with a semiconducting detector from especially pure germanium, and radon radiometers is featured. The reproduction consists in physically embodying units according to their determination with reference to the formation of radon and thoron in the radioactive radium and thorium series. The proposed approach makes it possible to determine design, structural, and other technical decisions of measurement standards, as well as specific approaches and methods of working with them. The creation of reference tools and technologies for reproducing the units of volumetric activity of radon and thoron and radon flux density from the ground surface makes it possible to ensure unity and reliability of measurements in the field of ionizing radiation, traceability of units, and bringing the characteristics of national standards to correspondence with the level of world achievements.

The composition of GET 20–2014, the State Primary Standard of the unit of activity and unit of volume activity of nuclides in beta-active gases is presented. Methods of reproduction and transmission of the units of activity and volume activity of nuclides in beta-active gases are described. Possible sources of error are indicated. a quantitative assessment of these errors is constructed, and scientific and technical solutions to decrease or eliminate the infl uence of sources of the errors on the results of measurements are described. GET 20–2014 supports the uniformity of measurements of the activity and volume activity of radionuclides in different spheres of activity at nuclear power stations, enterprises involved in the recovery and processing of nuclear fuel and materials, and elsewhere. In the nuclear industry, GET 20–2014 assures the radiation safety of researchers working in power plants and in the environment involved in the creation and introduction of new generations of BN-800 fast neutron reactors and the design of the BN-1200 new and promising more powerful reactor.

The spectrum of neutrons near the target of a portable NG-24M neutron generator is measured by the neutron activation method. The recovered neutron spectrum is represented analytically as a superposition of known physically substantiated spectra.

The present article considers a method of phase comparison of the instantaneous values of the frequencies of quasi-harmonic signals with slowly varying parameters, based on a parametric algorithm for estimation of the lag angle. It is shown that the errors of the method are comparable with the errors of the classical quadrature heterodyne method in comparing signals with constant frequency difference. The advantage of the proposed method lies in a four-fold reduction in the number of computational operations. The theoretical conclusions are supported by numerical and field experiments.

We investigate a nonlinear parametric method of estimating the instantaneous frequency and amplitude of a quasi-harmonic signal. We obtain analytical expressions for variance estimates and their displacement, confirmed by numerical simulations. Experimental verification of the method on a real signal confirmed the ability to determine its frequency with a relative error less than 10–5 in a time interval of about 30 periods of the test signal.

We present results investigating the characteristics of neutron fields in three channels of a graphite prism with a radionuclide neutron source 238Pu(α, n)9Be, located at its geometric center, and in the central channels of cylindrical moderators installed near the cores of the reactor BARS-6.

A Doppler lidar by means of which remote measurements of the speed (in the range 0–55 m/sec) and direction of wind at specified heights (3–300 m) along with processing, representation, and transmission of the obtained data to an operator’s computer may be performed is created. The lidar is intended for off-line continuous operation in different weather conditions. Results of studies of its technical and metrological characteristics are presented.

A method for measuring the induced activity in neutron activation detectors using gamma spectrometers with scintillator and semiconductor detectors is introduced. The sensitivity of the gamma spectrometers is measured as a function of γ-ray energy over a range of 0.06-3 MeV.

This is a description of the overall structure of an absolute ballistic gravimeter in which a test object moves freely in a vacuum in the gravitational field. This system is intended for determining the acceleration of gravity using measurements of length and time intervals in the equation of motion of the test object. These intervals are measured by a laser displacement interferometer and a system for precise measurement of time intervals, which are incorporated in the gravimeter. Uncertainties in the measured acceleration of gravity and metrological support of absolute ballistic gravimeters for length and time measurements are discussed.

A new principle for the construction of an angle sensor based on a periodic optical raster and a photodetector matrix is proposed. An algorithm for determining the angular position of the axis is considered. Theoretical and experimental estimates of the error in measurements of the angle and a comparison of the estimates are presented.

The use of a system approach to describe the properties of the International Temperature Scale (ITS-90) is proposed. A model is presented which enables the error of the difference between the ITS-90 and the thermodynamic scale to be estimated. The possibility of estimating the static chaos of the results of temperature measurements is considered.

We propose a new matrix method for calculating geometric image rotation, taking into account the effects of the geometric and dynamic phases in a nonplanar optical layout. In order to describe the propagation of light in this system, the algebra of two-dimensional Jones polarization vectors and matrices in two-dimensional space is extended to three-dimensional space. We give practical examples of nonplanar layouts of polarization nulling interferometers for application in astronomy and precision wavefront analysis.

Simulating spine pathology states is considered on the basis of optical topographic studies and three-dimensional reconstruction of the spine surface, where an analytic relationship is established between the bio-object state parameters.

A method of investigating the stresses in solid and dynamically loaded models, which are prototypes of individual components of a complex biosystem, is proposed. The method enables the experiment to be simplified considerably and considerably reduces the time required.

A method of determining the stresses that arise in individual elements of a complex system and that lead to deformation of these elements is proposed. Using the proposed method, the relationship between the topology of a surface of an object, the deforming load, and the interference pattern is established.

A method of measuring the viscosity of a liquid over a wide range of pressures and temperatures and a rotation-type viscosimeter which employs this method are proposed. The possibility of determining and automatically regulating the flow of a liquid using the results of measurements of the viscosity in real time by employing two viscosimeters, placed in different sections of the channels, is pointed out.

The intensity of photon radiation with energies of 20.15, 22.77, 295, and 497 keV in the decay of 103Pd has been measured relative to the 357-keV spectral line. The results have confirmed that there is a discrepancy between the evaluated data for 103Pd KX and gamma radiation. An interrelated system of absolute intensities for those energies is proposed.

A technology is described that decreases the time drift of the Zener stabilization voltage, shortens the run-in time, and reduces the low-frequency noise amplitude.