Vol 61, No 2 (2018)
- Year: 2018
- Articles: 15
- URL: https://journals.rcsi.science/0543-1972/issue/view/15340
General Problems of Metrology and Measurement Technique
Guide to the Expression of Uncertainty in Measurement: Problems, Unrealized Capabilities, and Revisions. Part 1. Terminological Problems
Abstract
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.
Article
Use of Time Series to Generate Intervals of Similar Behavior of the Parameters of an Object with Different Methods of Prediction
Abstract
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.
Modeling, Reproduction, and Mapping of Geofields With and Without Measurement Noise. Part 6. Piecewise Polynomial Approximations, Statistical Design of Experiments, and the Construction of Contour Maps
Abstract
Spline, finite element, and piecewise polynomial fits of the boundaries of geofields with automatic matching are examined. The unknown coefficients of the approximating polynomials are estimated using measurements of their input and output coordinates in the presence of measurement noise. A new method for constructing contour maps is developed on the basis of the fundamental “recurrence” theorem of Poincare. The capabilities of this method for constructing contours are examined.
Results of Observations of Navigation Satellites in Special Sections of Their Orbits
Abstract
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.
Application of the Impact-Echo Method for Measuring the Speed of Sound in Testing Cubic Specimens of Concrete for the Evaluation of Its Strength
Abstract
It is shown that the shadow method aimed at measuring the speed of sound in test cubic specimens of concrete for the subsequent evaluation of the strength of this material leads to errors caused by the effect of geometric dispersion of the speed of sound. We propose a more precise method for measuring the speed of sound in compact test cubic specimens based on the use of the impact-echo method.
Variable-Induction Transducer for Use in Determining Local Defects in Steel Rope
Abstract
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.
Linear and Angular Measurements
A Procedure for the Evaluation of Functional Parameters of the Three-Dimensional Structure of Surface Roughness Specified by the ISO Standards
Abstract
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.
Mass Measurements
A Procedure of Measurement of the Mass of Erythrocytes in Variable Electric Fields
Abstract
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.
Optophysical Measurements
Influence of the Duration of Laser Pulses on the Error of Reproduction and Transfer of the Unit of Energy
Abstract
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.
Mechanical Measurements
Aerodynamic Errors of the Systems Aimed at Measuring the Static Pressure of an Aircraft in the Sliding Modes of Flight
Abstract
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.
Thermal Measurements
Using Variations in the Frequency of a Ring Oscillator to Measure the Thermal Resistance of Digital Integrated Circuits
Abstract
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.
Electromagnetic Measurements
Eddy Current Monitoring Device for Cleanliness of a Working Liquid
Abstract
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.
Radio Measurements
A Method of Generating Ultra-Short Radio Pulses
Abstract
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.
Ionizing Radiation Measurements
Digital Processing of Measurement Information in Radioisotope Devices
Abstract
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.
Physicochemical Measurements
Determination of the Integral Content of the Components of Substances in the Control, Recording, and Monitoring of Production and Generation of Waste Products in Industrial Quantities
Abstract
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.