Vol 61, No 10 (2019)

The composition and metrological characteristics of GET 86–2017, the State Primary Standard of the units of radiometric quantities and units of spectroradiometric quantities in the range of wavelengths from 0.2 to 25.0 μm, are presented. The technical characteristics and operating principles of four new plants which were introduced as components of the standard to increase the precision of reproduction and transmission of the unit of spectral density of radiance, unit of spectral density of radiant intensity, and unit of spectral density of irradiance, as well as for the purpose of reproduction and transmission of the unit of the spectral density of the total radiation flux, unit of irradiance, unit of radiance of monochromatic radiation, and unit of spectral density of the radiation flux of the excitation and emission of fluorescence are described.

Data on the composition and basic metrological characteristics of State Primary Special Standard GET 148–2013 of the units of the strength of electric and magnetic pulse fields with pulse rise time in the range from 0.1 to 10.0 ns are presented. GET 148–2013 reproduces electromagnetic pulses of amplitude up to 300 kW/m (800 A/m) with minimal pulse rise time 100 ps. A new regime of reproduction of the unit of high pulse strength by the method of voltage–field–voltage double conversion is investigated. For this purpose, a comparator constructed on the basis of the principles of microwave photonics with rise time of the leading characteristic less than 100 ps is to be introduced into GET 148–2013.

The effect of the instability of the sensitivity of a matrix receiver on the results of the measurements of spatial-power characteristics of a laser beam is studied. Dependences are derived that make it possible to estimate the measurement error of the beam diameter, angle of divergence, and centroid coordinates, determined according to GOST R ISO 11146-2008 and associated with the instability of the sensitivity of components of the matrix receiver.

We present the results of investigations of an installation aimed at the transmission of highly stable 1 PPS time signals from the hydrogen time and frequency standard over a 150 km optical fiber communication line with the use of active electronic compensation of time delays. The error (mean-square deviation) of transmission of time signals does not exceed 80 psec on the daily interval of averaging. The installation enables us to guarantee the synchronization of the time scales of remote time and frequency standards included in the primary and secondary standards of time and frequency units.

Based on the analysis of time series compiled from the values of a controlled parameter, we propose options for constructing vectors (vector-neighbors), close to the starting vector. It is shown that the use of the coordinates of the constructed vector-neighbors in conjunction with the coordinates of the starting vector allows one to increase the sample sizes for determining the statistical characteristics during prediction of parameter drift and to increase the reliability of the estimates of these characteristics.

Features of the measurement of displacements of a sample by the positioning system of a probe microscope for studies of segments of the surface exceeding the field of view of the microscope are examined. The need to match the positioning step size and the field of view of the microscope is demonstrated. The use of an accelerometer and of a method for statistical differentiation of overlapping images for measuring the displacement of a sample is described. It is shown that the reliability can be increased by combining the results of measurements obtained by these two methods.

A method of attenuating high-power laser radiation using a small metal diffraction grating as an attenuator for power measurement was analyzed. The thermal operating modes of the attenuator were investigated, and various systems of cooling were considered. Errors of the coefficient of attenuation that are associated with the polarization and spectral composition of the radiation, and by the radiation absorption, mechanical deformation, and temperature mode of the diffraction grating are estimated. It is shown that a small metal diffraction grating can be used as a calibrated attenuator of powerful laser radiation with wavelength 1.06 μm. The relative error of the attenuator was 0.64%.

We study the possibility of application of SATRE modems for the transmission of reference time signals with optical carrier over fiber lines with lengths of up to 200 km. We experimentally estimated the uncertainties of comparison of time scales for the fiber communication lines with the help of SATRE modems.

Results are presented from studies of the estimation of the average power of signals with phase fluctuations of the components of harmonic oscillations. These studies take into account the spectral composition of the signal, as well as the characteristics of the phase fluctuations, along with the aperture uncertainty and sampling frequency of an analog-to-digital converter. Analytic expressions are obtained for the numerical characteristics of the distribution of this estimate for a normal probability distribution of the random quantities with uncorrelated random processes.

A dielectric moisture meter is described in which moisture content is determined from the phase shift angle between the increments in the total conductivity of the measurement capacitor of the probe of the moisture meter and its reactive component. These increments are produced by introducing sample material into the capacitor. This kind of moisture meter is shown to be insensitive to the mass of the sample, but is quite sensitive to its moisture content. By comparison with other mass-insensitive moisture meters, this meter has a simpler design and has smaller measurement errors because of a reduced number of measurement and computational operations.