Том 61, № 2 (2018)

The problem of discrepancy between certain statements of the Guide to the Expression of Uncertainty in Measurement and the State System for the Assurance of the Uniformity of Measurements is considered. Possible variants in the agreement between the statements of these documents as a function of the objective of the particular measurement problems solved are presented.

New approaches to the construction of intervals of analogous behavior of the parameters of an object from time series are considered. The intervals are constructed in the form of certain sets of sequential values of the parameters (coordinates of neighbor vectors) that are close to the set of their final values which are used in the prediction. It is shown that through the use of the newly constructed technique it is possible to increase the number of neighbor vectors for the purpose of finding statistical characteristics. A unified algorithm for finding a set of neighbor vectors in each of the variants considered is proposed. An algorithm for one step ahead prediction based on an analysis of the coordinates of the neighbor vectors is constructed.

The data of measurements of the power of radionavigation signals are accumulated for navigation satellites passing through special sections of their orbits. By analyzing these data, we reveal the variations of the power levels caused, possibly, by the changes in the angles of viewing of these satellites. We also describe the results of the observations of the navigation satellites performed by using various antenna systems. The obtained data are in good mutual agreement.

A magnetic method for the detection of wire ruptures in steel ropes is considered. A mathematical model of a magnetic method is proposed and analyzed. It is shown that the parameters of a measuring junction with variable-induction transducer may be optimized to increase the reliability with which wire ruptures are detected.

We propose a procedure for the evaluation of functional parameters of the three-dimensional structure of surface roughness by using the Mathcad software. The results of computation of these functional parameters for the working surface of the end gauge-block are presented.

We present the experimental results of measurements of the masses of a separately observed erythrocyte and a latex particle placed in a variable electric field. We show that the experimentally measured and theoretically computed masses of reference latex particles are in good agreement.

It is shown that the application of integrating radiation detectors makes it possible to reproduce and transfer a unit of energy of a short laser pulse without measuring its duration. We determine the conditions of energy measurements under which the error depending on the duration of the pulse can be neglected.

We propose mathematical models of errors of the onboard measurements of static pressure of an aircraft in the sliding modes of flight based on the use of hydrodynamic models of flow around thin bodies. We also analyze and estimate the schemes of location of Pitot static probes traditionally used in the aviation practice, as well as the algorithms intended for the compensation of errors in the calculators of air-data systems. The results of determination of the component of aerodynamic error in the sliding modes of flight are presented. The accumulated data have been obtained in the course of flight tests of numerous transport aircrafts.

We propose using logic-element time delay as a temperature-sensitive parameter to measure the thermal resistance of digital integrated circuits. We show that the frequency of a ring oscillator constructed using logic elements is inversely proportional to the signal delay time and is a linearly decreasing function of the temperature. We describe a technique for measuring the thermal resistance of a digital integrated circuit as it is heated by its own power consumption.

The principle of construction of an eddy current detector for monitoring the cleanliness of the working fluid of hydraulic systems and aircraft engines is described. The parameters of the impurity particles are measured with an eddy current transducer included in an active oscillator circuit. The results of experiments with particles of copper and steel grade ShKh-15 are presented. The limiting sensitivity of the detector is obtained from the diameter of the detected particles.

A method of generating short nanosecond radio pulses from a sequence of long radio pulses is considered. It is shown that the proposed method may be used in the appropriate laboratory studies and tests of equipment intended for the reception and processing of wideband and ultra-wideband radio pulse signals. An algorithm and technique of generating short radio pulses are proposed. A detailed theoretical derivation of analytic expressions that describe the form of short radio pulses as well as a calculation of the permissible limits of the amplitude and phase errors of sinusoidal signals used to generate radio pulses are presented.

The procedural error of a radioisotope measuring device due to the stochastic nature of the useful signal and the nonlinearity of the characteristic of the sensor is analyzed. Formulas for calculating the procedural error in the approximation of a given nonlinearity by a polynomial are presented.

The problem of finding the integral content of the components of substances and materials for a given volume and mass of a substance (material) at certain moments or time intervals based on weighted average estimates is considered. The solution of the problem is important for control, recording, and monitoring of production of substances in industrial-scale volumes, generation of waste, including emissions and discharges. Formulas are given for calculating the total standard uncertainty of weighted average estimates, taking into account the uncertainty of the values of the weighting coefficients of the estimates, due to the uncertainty of the mass measurements of the analyte.