No abstract

Research has been carried out in the field of ensuring the stability of transmitters, which are designed to work in extreme conditions. The complexity of the solved problems and the need for a systemic approach, including structural, material science, are noted. Approaches of leading foreign and domestic companies - manufacturers of sensors and measuring systems to issues of metrological reliability of measuring transducers have been analyzed. Ambiguity of interpretation of the term “stability” by various developers and manufacturers of sensors is shown. Most often, the accompanying documentation for sensors, as well as prospectuses and catalogs indicate a qualitative characteristic, and very rarely quantitative parameters. At the same time, international quality standards indicate the need to disclose qualitative indicators and translate them into quantitative data. The concept of ensuring stability of sensors during their life cycle, based on international quality standards and new design and technological solutions, is proposed. On the example of the beam sensitive element of the metal film pressure sensor, a specific effective technique for stabilizing the electrophysical characteristics of the film heterostructure is shown.

Sensors used in rocket and space technology are subject to extreme external influences in terms of temperature, vibration, and shock. Therefore, the choice of the type of sensors is justified precisely by the resistance to such factors, as well as the ability to ensure the temporal and parametric stability of measurements. A new type of sensors – fiber-optic ones – meets these conditions. The basis for the selection and further improvement of such sensors were such requirements as minimum power consumption, high accuracy and stability of measurements, the ability to combine several measurements in one sensor. It is noted that for space infrastructure the factor of the possibility of simultaneous measurement of several parameters with one sensor is one of the important quality indicators. This is due to the possibility of reducing the number of sensors themselves, which reduces the mass and size parameters of space technology. This applies, first of all, to measurements of pressure and temperature, since they, in aggregate, account for at least 40 % of all measurements in space products. The path of choos-ing the types of methods and sensor designs led to the combination of the amplitude conversion method and optical communication in one sensor. In this case, amplitude modulation of pressure and temperature is carried out by a microelec-tromechanical unit (module), and the modulated optical signal is transmitted by an optical module. Such a modular composition of the sensor makes it possible to dispense with optical ana-lyzers (interrogators) and carry out further pro-cessing based on standard interfaces. A limitation of the proposed methods and designs is the need for microelectromechanical structures that measure certain physical quantities. Such structures for fiber-optic sensors are not mass-produced; therefore, their manufacture can be established at instrument-making enterprises with microelectronic equipment

The microstructures of carbonized rice husk (CRH) and apricot stone (CAS) were studied to understand its adsorption of crude petroleum from water. Carbonize temperature affects the pore development of CRH, resulting in elongated large pores, as evident from the SEM data. The sorption capacities of CRH and CAS were compared in relation to different petroleum products. It was evaluated their possible practical use for water clean up from petroleum spills.

The objects of research are the designs and manufacturing technologies of a combined fiber-optic sensor. It is used in extreme operating conditions. The essence of the task is to study the constructive and technological compatibility of optical and micromechanical principles of simultaneous measurement of several heterogeneous physical quantities. In this regard, the chosen modular conversion principle solves the problem of combined conversion. The developed design and technology of the electro-adhesive connection make it possible to significantly reduce the internal mechanical stresses in the sensor and thereby increase the stability of the combined sensors in extreme operating conditions. Analytical models linking the magnitude and orientation of internal mechanical stresses with the characteristics of temporary stability for complex structures, as a rule, are absent. In practice, the obtained research results can be applied to combined pressure and temperature sensors, pressure and vibration, etc.