Phase liquid crystal (LC) spatial light modulators (SLM) are widely used for optical reconstruction of diffraction optical elements, including holograms. For this purpose high stability and linearity of phase response of SLM is required. In modern high resolution SLM digital signal addressing scheme which leads to emergence of effect of phase shift fluctuations during frame time is applied. In this paper measurements of character and peculiarities of modulation of phase shift of modern high-resolution LC SLM Santec SLM-200 were performed. Optical reconstruction of images from diffraction elements of different types was carried out, the quality of reconstruction and diffraction efficiency were assessed.

The problem of insufficient detail of the requirements for the developed and certified measurement methods used in mechanical testing of various materials is considered. The compatibility of the requirements of metrological support for the results of quantitative chemical analysis and indirect results of mechanical tests for the wear resistance of materials when rubbing against a fixed abrasive is relevant. To ensure the accuracy of measurements, it is proposed to use the grain size of the abrasive material and the rotation speed of the abrasive disk as variable factors. In order to establish the requirements for the metrological characteristics of materials during mechanical tests, in particular, when determining the relative wear resistance, the conditions for precision measurements are justified. The results of a multi – stage experiment-testing of materials for wear resistance with the use of various research and consumables, measuring instruments and testing equipment-are presented. The conditions for the organization of the experiment in the case of determining other relative mechanical characteristics of the materials under study for establishing precision indicators in the development of methods of mechanical tests for abrasive wear are proposed and justified. The application of the obtained results will allow developers of mechanical testing methods to establish metrological characteristics of materials in compliance with all the requirements of the State System for Ensuring the Uniformity of Measurements of the Russian Federation.

The problem of the absence of methods for measuring low-frequency fluctuation processes at high temperatures is considered. An original bridge method is proposed for measuring the spectra of low-frequency current fluctuations in tungsten filaments of electric lamps in a controlled temperature range of 300–2700 K. Application of the bridge measurement scheme allows us to reduce the influence of degradation processes in the filament and the power source's own noise on the measurement results by several orders of magnitude. Spectral analysis of low frequency current fluctuations is performed at the frequency range 1.5∙10^–5–5∙10^–1 Hz using an automated setup based on a personal computer under the control of specially developed software.

The need to develop a new state verification scheme (SVS) is caused by the emergence of high-precision bridges, resistance measures and boxes with a low temperature coefficient (0,02–0,5) ppm/К, highly stable transient measures, electronic resistance calibrators, and high frequency resistance measures. Recommendations how to assign the status of a working standard to measures, R-meters and measuring shunts with accuracy from 0,005 % to 0,500 %, sufficient for verification of measuring instruments, are given. SVS consists of two parts: part 1 covers electrical resistance measures, boxes and R-meters, part 2 – to measuring shunts and shunt resistance meters. Part 2 was introduced to the SVS for the first time. The revised indicators of accuracy for working standards of all levels are considered, conditions for the investigation of measuring instruments for assigning the status of a working standard, criteria for assessing metrological characteristics are given.

There are given the results of influence the level quantization to the accuracy of measured AC voltage by digital voltmeter. It is shown the influence of sampling frequency and the type of digital filter to effective digit capacity of conversion in case of synchronous and asynchronous sampling. There is obtained an estimate of error by representing the quantization error by centered noise with a uniform distribution. There are presented the results of modeling a digital voltmeter.

Amplitude and phase problems in physical research are considered. The construction of methods and algorithms for solving phase and amplitude problems is analyzed without involving additional information about the signal and its spectrum. Mathematical models of the amplitude and phase problems in the case of one-dimensional and two-dimensional continuous signals are proposed and approximate methods for their solution are constructed. The models are based on the use of nonlinear singular and bisingular integral equations. The amplitude and phase problems are modeled by corresponding nonlinear singular and bisingular integral equations defi ned on the numerical axis (in the one-dimensional case) and on the plane (in the two-dimensional case). To solve the constructed nonlinear singular and bisingular integral equations, spline-collocation methods and the method of mechanical quadratures are used. Systems of nonlinear algebraic equations that arise during the application of these methods are solved by the continuous method of solving nonlinear operator equations. A model example shows the effectiveness of the proposed method for solving the phase problem in the two-dimensional case.

The features of the propagation of electromagnetic waves in strip transmission lines have been studied. Methods for measuring the phase velocity and attenuation coefficient of an electromagnetic wave in strip transmission lines are considered. The problem of the lack of methods for measuring their wave impedance is analyzed. A method is proposed for determining the intrinsic parameters of strip lines from the results of measurements by a vector analyzer of S-parameter circuits of electrically long and short lines in a coaxial channel. The intrinsic parameters of the strip lines are determined by the proposed method in the frequency range 0.01–26.50 GHz.

The necessity of spectrometric measurements of neutron fluxes in the nuclear industry for the correct estimation of the radiation density and dose characteristics is justified. It is pointed out that the metrological and methodological support for not only spectrometric, but also radiometric measurements of arbitrary neutron fluxes is imperfect. The concept of a real-time multi-detector neutron spectrometer and the results of the study of its prototype are briefly described. To increase the reliability of the results of neutron measurements, it is proposed to verify a multi-detector neutron spectrometer-dosimeter of real time and existing radiometers-dosimeters of neutron radiation in reference neutron fields with different and reliably known forms of energy spectra. To create reference neutron fields, a neutron test and verification complex was developed and its layout was created. The model was experimentally tested in laboratory tests of a prototype of a multi-detector neutron spectrometer-a real-time dosimeter. It is proposed to train a neural network embedded in a multi-detector neutron spectrometerdosimeter on an extended set of basic spectra, which includes, in addition to the reference field spectra, reliably known spectra of neutron fluxes described in the literature. The procedure for forming a set of model implementations of training and test samples used in training a neural network is presented. It is shown that it is possible to exclude the energy errors of the proposed multi-detector neutron spectrometerdosimeter of real time when measuring neutron fluxes, even when checking in reference fields with a limited variety of spectral forms. The possibility of minimizing the energy errors of existing neutron radiometers-dosimeters during verification in the reference neutron fields of the developed test and verification complex is justified.

Modern calibration of hydrophones at megahertz frequencies is based on the method of optical interferometry, in which the vibrational velocity of an acoustic wave is measured using a thin sound-transparent polymer foil (membrane), metallized on one side to improve light reflection and installed in an ultrasonic field, followed by its replacement with a hydrophone to be calibrated. The main problem of implementing this calibration method is to assess the adequacy of tracking vibrations of the metallized side of the foil to vibrational displacements of water particles under the action of a sound wave incident on the opposite side of the foil. On the basis of the simplified theory of acoustic plane waves passing through layers of dissimilar materials, methods for measuring the speed of sound in the applied foil and an algorithm for calculating the frequency dependence of the sound wave transmission coefficient (in terms of vibrational velocity) from water through the foil to water or air, introduced as a correction to the results of hydrophone calibration, were developed. The uncertainty of the introduction of this correction is estimated.

Increasing the efficiency of cardiological diagnostics based on the analysis of human heart rate variability necessitates the development of accurate methods for detecting the R-waves of the electrocardiosignal (ECG signal). A technique for detecting R-waves of an ECG signal based on the wavelet multiresolution analysis (WMRA). The proposed technique for detecting R-waves includes sequential stages of digital processing of an ECG signal: WMRA; a set of nonlinear operators; adaptive algorithm for detecting signal peaks. A comparative analysis of the proposed technique with existing approaches to the detection of R-waves of the ECG signal has been carried out. To obtain quantitative characteristics of evaluating the efficiency of detecting R-waves, we used imitation modeling of an ECG signal containing noises and interferences of various intensity and nature of occurrence. The effectiveness of the considered approaches to the detection of R-waves of the ECG signal was investigated for clinical recordings of ECG signal. The absolute error of measuring the RR-interval durations for model signals with different noise levels is estimated. It is shown that the proposed method for detecting R-waves of an ECG signal based on WMRA is characterized by small errors in measuring the duration of RR-intervals, high rates of true detection and small errors of false detection and omission.