Volume 60, Nº 9 (2017)

The concept of the transfer matrix of a block of the energy information circuit of a measurement device in the LT basis of the Bartini system of kinematic quantities is introduced with space and time constituting the resources of the basis. A numerical estimate of the costs of the space-time resources expended in the transformation of a known input quantity of the block into a known output quantity is proposed. Recommendations for synthesis of the physical principle underlying the operation of a measurement device possessing minimum resource capacity equal to the sum of the costs of the resources of the blocks of the circuit are given.

A new method is proposed for the measurement of the spectrum of the sizes of suspended nanoparticles based on enlarging the particles through condensation growth in a medium of a supersaturated vapor and measurement of the parameters of the resulting grown droplets. By means of the method, the lower limit of the measurements can be reduced down to several nanometers and an array of data on the spectrum of the sizes of nanoparticles stored for subsequent use.

Features of the mechanism of pointwise tribometric interaction of silicon dioxide substrates in estimation of the cleanliness of their surfaces are investigated. It is shown that the lower the speed of the probe substrate, the greater the sensitivity of the tribometric system to variations in the concentration of the surface electronic states. Measurement of the acceleration of a probe substrate after it starts to move in the time interval 0 ≤ t ≤ 0.012 sec is suggested. This will make it possible to reduce the error in the degree of cleanliness of surfaces down to 11%.

We analyze the conditions under which radial nozzles can be used to measure or regulate the flow of water at high pressure drops. Using the URANS model, numerical simulation of water flow in radial nozzles was carried out. We find a dependence that establishes a relationship between the minimum static pressure on the geometric contour of a radial nozzle and the pressure drop across the nozzle, which leads to an estimate of conditions for the onset of cavitation.

A technique for the measurement of the parameters of three-dimensional nonresonant dipoles is proposed. The technique is based on measurements of the currents travelling through the dipoles and the phase shifts that occur as alternating voltages of two fixed frequencies are fed to the dipoles. An algorithm for performing measurements and processing results by means of the circle diagrams of currents at two near frequencies with iterative measurements of angles is considered. It is shown that the new technique may be successfully used to determine the parameters of three-element nonresonant dipoles with unique reactive component.

Solutions for structural and parametric optimization of spectrum filtering devices used in the measurement of the parameters of signals designed to expand the frequency range of the measuring devices and support measurements in the case of low signal-to-noise ratios are obtained.

A method of analytic solution of the problem of aperture delay in digital systems used for the measurement of the controlled state variables of linear deterministic systems is proposed. The mathematical apparatus for deriving an explicit form of the solution of linear differential equations, which is based on the matrix exponential operator and yields a low computer time, is used. It is shown that the proposed method may be effectively used to eliminate aperture delays if the measured parameters are dynamically related state variables of the controlled system. An algorithm and example of a solution that illustrates the efficiency of the proposed method are presented.

Features in the process of monitoring the diameter of tension springs and other spiral-like bodies in the course of their manufacture are considered and the selection of an optoelectronic method of measuring the diameter of a spring is evaluated. Structural data and the characteristics of a newly designed sensor that satisfies the technological requirements are presented. A technique for calibrating the sensor is proposed and implemented. Testing of the sensor in an actual production process is performed. Satisfactory results from a comparison of the estimators of the diameter performed by the optoelectronic technique and by indirect techniques are obtained.

A conical meter of the energy characteristics of laser radiation containing two spatially separated groups of thermopiles is proposed. It is shown that an error of the detector’s zone characteristic of less than 1% may be achieved by appropriate selection of the branch resistance in the circuit of the voltage source which is the most sensitive element to heating.

We present a system of transmission of reference frequency and time signals to non-interrogating and interrogating measuring facilities of the ground-based GLONASS complex for control of onboard time scales of the navigation system spacecraft. The proposed transmission system is implemented using fiberopticcommunication lines. We present results of experimental studies of the error in the transmission of reference frequency and time signals using fiber-optic communication lines.

We describe a method of pressure measurement using a Kurant DI-V strain-gage sensor as part of an experimental setup for investigating the isochoric heat capacity and pVT property of liquids and gases. We compared the experimental measurement results with the readings of an MP-600 manometer and data from the National Institute of Standards and Technology (NIST, USA). The efficiency of the use of the indicated strain-gage pressure sensor is shown.

Results are presented for the solution of the problem of gas flow in a porous body with the presence of a temperature “step” in the range 1–100 of the non-dimensional heat-transfer coefficient, while accounting for longitudinal thermal conductivity. The problem was solved using the numerical finite difference method. Maximum slope angles were derived for temperature curves that can be used to obtain the thermal characteristics of high-compact heat transfer surfaces with the single-flow non-stationary method. Recommendations were provided regarding the range of applicability of the method, taking into account the new received results.

An analytical model of the dependence of the capacitance of ceramic capacitors on applied voltage has been substantiated, both theoretically and experimentally. A method of determining the parameters of the analytical model was developed on the basis of an exact solution of the nonlinear differential equation of capacitor discharge. Experimental data for ferro-ceramic multilayered capacitors is provided. Correspondence of the results of the proposed method with data from direct measurements by an RLC measuring instrument and information specified by the capacitor manufacturer, throughout the working voltage range, is noted.

We consider various methods of measurements of the spectra of amplitude and phase noises of harmonic microwave signals and choose the most sensitive method of synchronous demodulation with two independent channels and the determination of the cross-spectrum. The results of measurements of the spectra performed by using a model of two-channel low-frequency analyzer, as well as the results of measurements of the spectra of phase noises of ultrahigh-frequency sources of various intensities, are presented and compared with the data of reference measurements.

A bispectral approach to signal processing is proposed which permits recognizing defects in engineering structures when inspecting the parameters of the surface wave field. The approach is based of using an adaptively adjustable orthonormal basis. A series of experiments demonstrating the high effectiveness of the approach is carried out.

The error of measuring atmospheric concentrations of radionuclides cesium, strontium, krypton, and xenon in the 10¹⁰–10¹³ cm^–3 range is estimated. Measurements were taken by differential absorption and scattering lidar with consideration of the laser radiation line width from the lidar composition during probing at distances up to 2 km. For a 25% relative error of measuring the concentration of a radionuclide at wavelength 852.1 nm, the minimum 70 m and maximum 1000 m probing paths for cesium with concentrations of 10¹¹ and 10¹⁰ cm^–3, respectively, were obtained.

The principle of sedimentation analysis for determining the particle size distribution of grain is described. The design and electrical scheme of a sedimentometric instrument, in which the grains are distributed depending on the velocity in the fluid are presented and their electrical conductivity during sedimentation is measured. The advantages of using the method of measuring conductivity compared to the traditional gravimetric (weight) method are given.