Vol 61, No 3 (2018)

The composition of the State Primary Standard of the unit of surface heat flux density, GET 172–2016, its metrological characteristics, and operating principle are presented.

Information to improve GET 198–2011, the State Primary Standard of the unit of power of magnetic losses, is presented. A plant for reproduction of the unit of magnetic induction of a constant magnetic field in the range from 0.1 to 2.5 T and unit of magnetic flux in the range from 1·10^–5 to 3·10^–2 Wb is introduced as a standard. Studies to improve the standard were carried out in 2015–2016. The composition, operating principle, and metrological characteristics of GET 198–2017, the State Primary Standard of the unit of power of magnetic losses and unit of magnetic induction of a constant magnetic field in the range from 0.1 to 2.5 T and of magnetic flux in the range from 1·10^–5 to 3·10^–2 Wb, are described. Information on preliminary comparisons is presented.

The properties of nonparametric estimation of the distribution function and estimations of the maximal likelihood of the parameters of distributions from interval data are considered. Samples of interval observations are required when the true value of an observation is not known, and only the interval this value belongs to is known. An investigation of the statistical properties of estimates of the distribution function and its parameters from interval data is performed by methods of statistical simulation and compared to estimates obtained from point samples of the midpoints of the observation intervals.

We describe the results of the algorithmic and software realization of the ISO 25178-2:2012 international standard and perform the numerical analysis of the errors of a spline space filter in comparison with the results obtained for a Gaussian space filter. The recommended parameters of the filters are determined. The algorithms and analytic software are developed in the process of investigation of the Russian standard base in the field of space 3D filtering of the surface irregularities.

Metrological problems that arise in measurements of the temperature of physical objects by means of pyrometers, where the emissivity of the objects is different from 1 and may vary with a variation in the wavelength, are considered. Factors are established and methods of eliminating inaccuracies in the radiation coefficient of energy-controlled pyrometers are presented. Violations in the traceability of pyrometers with built-in correction units relative to the state primary standard of the unit of temperature are discussed and recommendations for recovering traceability are presented.

A modification of the method of bisection for the purpose of searching for the root of a nonlinear equation is presented. Through the use of the modification, it becomes possible to use the method of bisection to solve equations of indirect measurements in full agreement with the metrological requirements imposed on the results of indirect measurements. It is shown that through the use of data on inaccuracies in the coefficients of equations that are the results of direct measurements it becomes possible to speed up the search for the root as well as achieving a reliable estimate of the characteristics of the error.

The problem of construction of an adaptive discrete Kalman filter is analytically solved with the use of irregular precise measurements. It is shown that the possibility of irregular precise measurements makes it possible to precisely determine the parameters of the filter (gain and adaptation factor) within the stage of their appearance and guarantees the error of estimation equal to zero. The indicated reconstruction of the parameters of the estimation algorithm significantly improves its convergence.

We propose a method for the estimation of the errors of coordinate measurements of the geometric parameters of the components on the basis of the data contained in the design and technological documentation. The a priori estimates of the error of coordinate measurements are required for the optimization of the methods of measurements and planning of measurements.

An indirect method of measuring the pulse pressure created on a pendulum-type installation is developed, without using a reference sensor. The basic technical characteristics of the installation are regulated. The possibility and expediency of using the developed measurement method are theoretically substantiated and experimentally confirmed.

A method is proposed for constructing radial type microwave devices forming a uniform temperature distribution throughout the volume of pipes made of polymer composite materials The results of theoretical and experimental investigations of the temperature distribution across the thickness of the pipe material are given. The advantages of microwave technologies for curing polymer composite materials compared to traditional methods are shown.

A theoretical description and practical realization of a method for in-process control of the capacitance per unit length of a single core electrical wire are given. The standards regulating measurement of wire capacitance are presented and the limitedness of their use for in-process control is pointed out. Methods of primary and operating adjustments of the capacitance meter minimizing the measurement error are developed. The problem of determining the actual values of the capacitance of wire specimens is examined. The design, operating principle, and results of factory tests of the CAP-10 capacitance meter are described.

The results of experimental investigations of the noise temperatures of the RT-13 radio telescope receiver system of a two-element radio interferometer with a very long baseline in the 2.2–2.6, 7.0–9.5, and 28–34 GHz frequency range are presented. The measurements were taken by wide-aperture low-temperature noise generators developed and certified on the standard baseline of VNIIFTRI. The error of measuring the noise temperatures of the radio telescope receiver system was determined. The confidence limits of the measurement error (for fiducial probability P = 0.95) were not more than 3.7 K.

The need for the development of acoustic methods for monitoring the stress-strain state of threaded connections is demonstrated. Methods and designs of acoustic measurements are presented. The result of the development of a specialized attachment that produces an increase in the precision with which mechanical stresses are determined in a threaded connection and introduction of the attachment into production are described.

We describe the development of a device for absolute activity measurements using the 4π (α, β)-γ coincidence technique. A Caen N6720 high-speed analog-to-digital converter (digitizer) was used to allow software to be substituted for the complex hardware components of such devices and simulate a coincidence channel in computer memory. This digitizer enabled us to substantially simplify the digital coincidence channel in the device. We studied the characteristics of the resulting device. The accuracy of radionuclide activity measurement was verified by comparison with the GET 6-95 primary State reference unit of radionuclide activity. The activity measurement results obtained with this device were found to be highly consistent with those obtained using the GET 6-95.

This article considers heart rhythm parameters and the method of primary processing of electrocardiograms. A comparative analysis of the dependences of the standard deviation and information entropy of real and virtual cardiac rhythm diagrams was carried out in terms of digitization frequencies. A model of cardiac rhythm regulation and control is offered. Correction of the numerical qualifier of functional state levels was carried out.

We have derived the basic equations underlying the design specifications for fused-quartz resonator flow tubes, as well as the equations for the amplitude and angular frequency of the oscillations; developed a design for a resonator detector with a quartz-glass resonator flow tube; and studied the vibrational modes for the quartz tubes in this resonator. We present equations for determining the sensitivity and estimated error of the sensor element in the resonator sensor.