Vol 60, No 1 (2017)

The structure of the National Primary Standard for the units of complex dielectric permittivity at frequencies from 10 Hz to 10 MHz is discussed. The measurement methods used in the standard for measuring dielectric permittivity and the dielectric loss tangent are described. The metrological characteristics of the standard and results of measurements of the dielectric parameters of reference standards are reported.

The distributions of the statistics of parametric tests (Neyman–Pearson, O’Brien, Link, Newman, Bliss–Cochran–Tukey, Cadwell–Leslie–Brown, and the Overall–Woodward Z-variance and modified Z-variance tests) are studied, including the case in which the standard assumption of normality is violated. A comparative analysis of the power of the set of parametric tests is carried out.

The a posteriori reliability of verification of measurement instrumentation under conditions of unequal measurement accuracy of tolerance monitoring systems is calculated and a computer program is used to estimate it.

We consider the problem of determining errors of mutual synchronization of satellite clocks in navigation constellations. We determine errors in receivers and transmitters of these satellites. We show how to use object parameters to compensate for these errors, provide more accurate coordinates of navigation satellites and increase the accuracy of solving navigation problems.

A mathematical model describing the processing of measurement information in the course of determining the reflection and transmission factors of radar-absorbing materials by means of sounding with the use of ultra-short electromagnetic pulses is proposed. The use of the method of kernel smoothing to eliminate the influence of the noise of the measurement equipment as well as a Fourier window transform for the purpose of realizing a transition to the frequency domain is evaluated. Estimation of the random and systematic measurements is carried out.

The temperature coefficient was determined for diamagnetic shielding of water protons for the temperature range typical of living tissues by comparison of the temperature shift of the signal of the water and the temperature shift of the signal of hydrogen. Tabulated data are presented that can be used for calculating the induction of a magnetic field from the frequency of an NMR signal of water when using spherical or cylindrical samples with their orientation parallel and perpendicular to the magnetic field lines. The temperature of brain tissues was estimated from magnetic resonance spectra accumulated by tomography without suppression of the water signal.

We describe the design and operation of the cesium frequency frame reference of fountain type CsFO2(SU), designed and manufactured at VNIIFTRI. We present the results of metrological studies that will enable us to more accurately assess the systematic frequency shifts of the frame and to refine the estimate of the unexcluded systematic bias of the cesium frequency frame of type CsFO2(SU), whose estimated value is of the order of 2.5 10^–16.

Calculation results are presented for the form factor of a flat ring in a linear formulation of the theory of elasticity. The form factor accounts for the influence of the sample dimensions and Poisson’s ratio on the modulus of elasticity being measured. The two-dimensional problem of elastic deformation of a ring with boundary conditions specified for its entire surface was solved. Six flat rings of various sizes were made and their modulus of elasticity was measured to validate the results of calculations. The dispersion of values of Young’s modulus, corrected by the calculated form factor, did not exceed 2.5%, which corresponds to the range of error of measurement methods for the modulus of elasticity.

A thermal flow sensor is examined, in the form of a battery made from Borelius elements assembled by means of interconnection soldering and adhesive insulating interlayers. The dependence of the sensing signal on time as well as on the sizes of design elements and the thermophysical parameters of structural materials is calculated. Results of calculation and experiment are compared. Methods for increasing the speed of such devices are proposed.

Solutions of the problem of expanding the dynamic range of spectral measurements of the parameters of low-level signals by means of artificial noising of the signals are found and evaluated.

Results of experimental investigations of the parameters of an element of a wave filter the structural design of which is based on the location of the pressure fluctuation detector in a cavity beneath a fine-mesh grid are presented. The optimal dimensions of the element at which maximal averaging of short wavelengths may be achieved are presented. A method of determining the efficiency of the filter is proposed.

A radiation-resistant diamond-based detector for registration of fluxes of particles of cosmic radiation with low linear energy transfer is developed and investigated. The device may be used to register gamma radiation of water-moderated, water-cooled nuclear energy reactors. The characteristics of a detector when exposed to beta radiation are determined and modeling of the signals of the device when exposed to beta and gamma radiation is performed. The use of a multi-layer diamond structure makes it possible to increase the signal-to-noise ratio and expand the dynamic range of measurements of the linear energy transfer of cosmic radiation particles.

The experimental method is described and the measurement results of the value of polarizability of erythrocytes and latex particles in a non-uniform alternating electric field are presented. The results show that the values of experimentally measured and theoretically calculated polarizablity values of latex particles are in good agreement.

The calibration and verification of liquid and aerosol particle counters are described. Aerosol particle counters are calibrated using latex spheres of known size. Depending on the design of the counters, the light scattered by the particles is detected at different angles. It is shown that detection of the scattered light at an angle of 90° leads to large measurement errors if the refractive index of the detected particles is not specified a priori. When the scattered light is detected over the entire solid angle, the error is substantially reduced. The metrological characteristics of counters with different designs are analyzed.