Vol 61, No 4 (2018)

Features and metrological characteristics of State Primary Standard GET 59–2016 of the unit of thermal conductivity and unit of thermal resistance are considered. The basic results of the three international comparisons CCT-S2, 495/RU/10a, and 549/RU/12a are presented.

Problems related to estimation of precision in connection with revisions to the Guide to the Expression of Uncertainty in Measurement are considered.

Problems related to the use of the concept of measurement uncertainty in different types of metrological problems, such as calibration, type evaluation, and the verification of measuring instruments are considered. A classification of risks in the assessment of the correspondence of measuring instruments to specific requirements is presented. Examples of conformity decision rules used in verification of measuring instruments are presented and the role of measurement uncertainty in these rules is demonstrated.

The error of measurement of hydrogen sulfide concentration ranging from 10¹⁰–10¹⁴ cm^–3 in the atmosphere by Raman lidar as well as differential absorption and scattering lidar at distances up to 2 km was estimated. It was shown that Raman lidar over measurement time of 100 sec can record such concentration of the studied molecules in atmosphere with a relative error of no more than 20% for the entire range of distances, and for differential absorption and scattering lidar at the wavelength of 3.83 μm the relative measurement error lies in the range of 20–26%.

A method for processing the signal of Doppler radio frequency sensors is given, which makes it possible to measure the ground speed vector of surface vehicles (cars, tractors, autocars, etc.). The possibility of constructing a real car route in a rectangular coordinate system is shown. Special algorithms for signal processing are considered which substantially increase the accuracy of determining the Doppler frequencies of the sensors.

We realized the improvement of a dielectric moisture meter in the form of elevation of its sensitivity to moisture with preservation of the independence of the results of measurement of the mass of the investigated material. In the improved meter, the moisture is found from the ratio of the sum of increments of the reactive and active components of the admittance of the capacitor sensor of moisture meter caused by placing the investigated material inside the capacitor to the difference between these increments or from the ratio of some other combinations of these increments. Both these ratios and the ratio of initial increments are independent of the mass of investigated material but much stronger depend on its moisture content. In practice, the application of these moisture meters can simplify the procedure of measurements and increase their accuracy.

An iterative method of probe radius compensation of mobile coordinate-measuring machines when controlling bodies of rotation is examined. The new method minimizes the angle between the normals at the specified point to the nominal and actual profiles as a result of successive approximations. Results of measurement and data handling showed high efficiency of the iterative method by comparison with known methods that are based on the least squares method. The greatest effect on reducing the error of probe radius compensation is reached with a small number of measured points and their non-uniform arrangement on the surface of the component part.

A method of monitoring the process of laser cleaning of monuments and other works of art in the course of conservation is presented. The capabilities of the method of laser-induced breakdown plasma spectroscopy in cleaning of monuments made of metal are considered. A photometric device based on an integrating cavity in the form of a cylinder is developed and investigated. The capabilities gained with the use of the device for proximate analysis of the efficiency of the process of cleaning the surfaces of sculpture made of marble and limestone structures are shown.

A reference quantum transported comparator of DC magnetic induction is presented, created on the basis of a two-zone measure of magnetic induction and a quantum system of automatic reproduction of the nominal parameters of the modulus of magnetic induction in the geomagnetic range. The reference comparator expands the functional capabilities of the State Primary Standard of the units of magnetic induction, magnetic flux, magnetic moment, and the gradient of magnetic induction of GET 12–2011, and makes it possible to calibrate and verify precision magnetometers in locations of mass application.

A new method for measuring the nonlinear distortions of frequency-modulated signals of promising generators has been experimentally confirmed. Signals are formed on the basis of direct digital synthesis. The advantages of this method for sensitivity, resolution of measurement and ease of implementation are shown.

We discuss a technique for measuring the frequency-dependent acoustic reflection coefficient of a material under test in a tank where the acoustic waves reflected by the tank surfaces cannot be neglected. The effectiveness of this technique was assessed by measuring the reflection coefficient at the air–water and water–reinforced-concrete interfaces. We describe the experimental results obtained at low frequencies (down to a few tens of hertz), in addition to several special considerations that apply to low-frequency measurements.

We have developed a measurement technique and describe a test bench for experimental gravimetric study of the adsorption of energy-carrier gases at pressures of up to 0.15 MPa and temperatures of 77–670 K on CNT/C₇H₈ supramolecular structures based on carbon nanotubes and toluene molecules. We show that at pressure 0.1 MPa and temperatures of 273 and 178 K adsorption of methane is approximately 1.5 times higher on CNT/C₇H₈ structures than on pure carbon nanotubes.

Formula (20) and (21) has been corrected. Also, on page 230, in the 7th line of the conclusion, it should read “estimated parameters of the decomposed model (9);”.