This article presents the results of a study of the tendency of composites based on magnesium oxychloride cements to deformation changes. The dependence of the degree of deformation of light magnesian concretes on the conditions of their hardening has been determined. The main factors influencing the deformation of light magnesia concretes have been established. The influence of hardening conditions on the intensity of deformation changes is shown. Revealed the reasons causing uneven deformation of light magnesia concrete. A method for the manufacture of light magnesia concretes has been determined, which prevents their uneven deformation and subsequent violation of the geometry of the structure. It has been established that the introduction of modifier additives, such as cellulose ethers, helps to reduce the delamination of concrete magnesia mixtures, improve their homogeneity and reduce the unevenness of deformation changes over the sample volume.

Keywords: magnesium oxychloride cement, volumetric deformations, shrinkage, expansion, warpage, hardening conditions

In the article we discuss temperature errors caused by non-stationary thermal processes in a thin-film Hall transducer. When solving the heat conduction equation we show the significant influence of effects of Peltier and Seebeck on the Hall voltage measurement results in the current switching mode. A new twenty-step switching currents algorithm for the Hall transducer is proposed. In this algorithm the additional voltages are measured at the absence of current through the transducer. From the additional voltages we estimate the contribution of the temperature drift. It was experimentally shown that for the PHE602117 converter the additive temperature error decreases by 30 times in comparison with the four-step algorithm while reducing performance by 20%.

Keywords: Hall transducer, additive error, Peltier effect, non-stationary processes, thermo-emf., magnetic measurements, current switching

With the growing fleet's increasingly acute problem arises safety and reliability their exploitation as a result of this increase in productivity and accuracy of their technical diagnostics. Urgent task to further improve diagnosis for vehicles is to develop new methods and algorithms highlight the dominant component of the information in relation to a wide class of vehicles. The methods joint time-frequency and wavelet analysis. To isolate the dominant component of the information proposed to use the method of wavelet decomposition. Using vibro acoustic registration nodes vehicles funds allowed to receive signals carrying information about the defects of individual units of vehicles. The proposed decoding algorithms signals have high reliability, allow technical inspection, subsequent monitoring of the technical state of the vehicle. Using vibroacoustic registration of vehicles allowed nodes receive signals carry-ing information about the defects of individual units of vehicles. The proposed decoding algorithms signals have high reliability, allow technical inspection, subsequent monitoring of the technical state of the vehicle.

Keywords: vehicle, vibroacoustic diagnostics, dominant information, time-frequency analysis, wavelet analysis

This paper describes a hardware-based and software system parametric estimation of signals. It`s experimental accuracy was achieved measuring the phase difference between the two quasi-harmonic signals at 10 μrad.  

Keywords: parametric analysis, technical diagnostics, the phase difference

Digital compact proton magnetometer was created for measure the geomagnetic fields, including the fields of high heterogeneity. We described design of the instrument and its principles of operation. This device is using implemented digital filtering techniques and Prony method to determine the frequency of the desired signal. The experiments were made in the fields of high heterogeneity and demonstrated the possibility of precise measurements in the fields with a gradient of up to 8 mT / m. The device can be used as a metal detector, as well as for magnetic prospecting, geological studies, etc.

Keywords: nuclear magnetic resonance, free precession, proton magnetometer, geomagnetic field, digital filtering, Prony method