High Metrological Characteristics Research Articles

ЗМЕНШЕННЯ ВПЛИВУ ВІДХИЛЕНЬ ПАРАМЕТРІВ ГЕНЕРАТОРІВ У ПРЕЦИЗІЙНИХ КВАДРАТУРНИХ МОСТАХ

The article is devoted to solving the problem of attestation of electric capacity standards at industrial frequency. The expediency of using a quadrature bridge of alternating current to determine the parameters of standards of electric capacity at industrial frequency by comparison with the parameters of standards of active resistance was noted. The advantage of using a bridge imbalance indicator with high input impedance is shown, which consists in the possibility of reducing the influence of higher harmonics of the supply voltages. An analysis of the well-known method of reducing of measurement errors caused by the deviation of the generator parameters from the calculated ones was carried out. It is shown that the known method does not provide sufficient compensation for the influence of these errors when the deviations of the generator parameters increase, as well as when the deviations of the bridge from the balance state increase. An iterative algorithm for calculating the measured deviation of the impedance ratio of the compared standards from the nominal value is proposed. Mathematical expressions for calculating the measured quantity are given. Calculations of the components of the measurement error for different values of generator voltage deviations were carried out. Calculations were performed for two variants of generator voltage variation implementation: multiplicative voltage amplitude variation and additive voltage phase variation. The developed iterative correction method allows to reduce the specified errors to the required levels in a small number of iteration steps - in the vast majority of cases, two steps are enough. The application of the method allows obtaining high metrological characteristics with rather large deviations of the voltage ratio of bridge generators, which makes it possible to reduce hardware costs when implementing quadrature alternating current bridges for comparing capacitance and active resistance standards. References 15, figure 1, table 1.

MEASURING THE SMALL LINEAR DISPLACEMENTS BY THE PHASE METHOD

A measuring device with a differential capacitive measuring transducer (CMT) designed to measure small linear displacements is considered. The CMT has a plane-parallel design of the plates, the natural input value is the change in the gap between the plates. In the measuring circuit (MC), model resistors with the same resistance are connected in series with the sensitive elements of the CMT. The voltage dividers formed by these connections are powered by counter currents of a high-frequency sinusoidal voltage generator. An informative measurement parameter is the phase shift angle between the two output voltages of the MC. These voltages are supplied to the analog inputs of the programmable microcontroller (PMC). The PMC controls the measurement process, measures the specified phase shift angle and determines the measured displacement. Thanks to the used algorithm for processing the measurement results, a ratiometric output signal is obtained to determine the measured displacement. This ensures high metrological characteristics of the meter. The theory of the meter's functioning, the features of the choice of nodes, and the method of calculating the parameters of the MC elements are described. A methodology for the theoretical study of measurement errors has been developed, and the results of their calculation for the implemented version of the meter are presented. It is substantiated that the relative measurement error of the developed device for small linear displacements does not exceed 0.065%. Ensuring high measurement accuracy is also due to the use of phase signals instead of potential-current signals.

Measuring Setup for Experimental Research of Two-Coordinate Fiber-Optic Acceleration Sensors with Cylindrical Lenses.

The article presents the possibilities of using fiber-optic acceleration (FOC) sensors on products of rocket-space and aviation technology as part of information-measuring systems. A special measuring device has been developed for experimental confirmation of the main characteristics of the technical characteristics of the developed, two-coordinate fiber-optic acceleration sensors. The developed measuring setup for the experimental research of a two-coordinate fiber-optic acceleration sensor with two, cylindrical lenses fixed on two H-shaped elastic elements deflected under the influence of acceleration in two mutually perpendicular directions X and Y, intended for operation in harsh conditions of rocket and space technology. The experimental equipment consists of the developed setup for setting micromovements and an information conversion unit, including modules for signal conversion, transmission, power supply, signal amplification, and indication. Experimental dependences of the output voltage from the information conversion unit’s output on the micro-displacement in the range corresponding to the micro-displacements of the inertial mass with a cylindrical lens under acceleration in the range of ±100 m/s2 were obtained on the micro-displacement setting unit. The maximum value of the linearity error of the prototype acceleration sensor together with the information conversion unit was 0.07%. The conversion sensitivity of a two-coordinate fiber-optic acceleration sensor per the experimental dependences obtained on the Data Physics LE-612 MST/DSA 10–40 k vibration stand when exposed to sinusoidal vibration with an acceleration amplitude from 2 to 10 g in the frequency range from 5 to 2560 Hz was, on average, 3 mV/m/s2. The conducted experimental research confirms the performance of experimental samples of fiber-optic acceleration sensors together with an information conversion unit, as well as the achievement of high metrological characteristics.

CORRECTION OF ERRORS OF THE MEASURING CHANNEL AVERAGE ACTIVE POWER

In the article is offered the structural scheme of error correction of the precision measuring channel of average active power for researches in laboratory conditions and exclusively within the limits of changes of the basic frequency of a network. A feature of the scheme is the use of calibration of functional transducers with piecewise linear approximation. The input voltages of these converters are a triangular voltage, which is formed at the output of the integrator by integrating rectangular bipolar meanders, which are formed from the output signals of the frequency divider phase shifter synchronized with the network by a device based on the original precision amplitude-pulse system of phase frequency tuning. Compensatory small-sized low-voltage transformers using measuring amplifiers with differentially split inputs are used as primary converters, which increases the linearity of the characteristic in a wide dynamic range, due to which additive-multiplicative correction of errors of the whole measuring path by two points is realized. The article presents the results of computer modeling of the main functional components of the measuring channel, which confirm its precision and high metrological characteristics. References 10, Figures 2.

Создание и валидация способа количественного определения бисопролола в новой фармакологической композиции "Бисопролозоль"

Introduction. When developing new pharmacologically active compositions and introducing them into extemporaneous manufacturing and industrial production, a comprehensive study of the properties of the medicinal product applying modern methods of analysis combining high metrological characteristics, expressiveness, sensitivity, accuracy, availability, reliability is mandatory. Development of analytical methods for quality control of new drug compositions is an urgent task of modern pharmaceutical analysis. Aim. Development and validation of a method for quantitative determination of bisoprolol in a new pharmacological composition "Bisoprolozol". Material and methods. To perform the analysis, we used pharmaceutical substance bisoprolol fumarate, glycerol hydrophilic gel "Tizol", ointment "Bisoprolozol" consisting of 0,5% of selective beta-blocker in titanium-containing glycerohydrogel. During the experiment, spectrophotometer SF-2000 and the method of absorption spectrophotometry in the ultraviolet region were used. Regression analysis of data obtained was performed in Microsoft Office Excel 2016 (OFS.1.1.0013.15 "Statistical processing of the results of chemical experiment"). The technique was evaluated according to validation parameters: specificity, linearity, correctness, and precision. Results. Studying the electronic spectral curves of bisoprolol we determined that its analysis is rationally performed at a wavelength of 274 nm (experimentally determined maximum absorption). In the course of the study we determined the sensitivity of the determination of the drug, which is equal to 5.260 µg/ml at A(min) = 0.02. The results of quantitative analysis of bisoprolol in the pharmacological composition "Bisoprolozol" showed that the mass of the selective blocker of adrenergic receptors (0.0409-0.0536 g) is within the acceptable limits according to the regulatory documentation for soft pharmaceutical forms (Order of the Russian Ministry of Health № 751n of 26.10.2015). Conclusion. In the present experiment, optimal conditions for the spectrophotometric method of analysis were selected, based on which the method of quantitative determination of bisoprolol in the new pharmacological composition "Bisoprolozol" with an error not exceeding ± 1.89 % was developed, validated and presented.

MICROPROCESSOR MEASURING SYSTEM FOR DYNAMICS AND ENERGY OF MOBILE MACHINES

The paper presents a synthesis of a microprocessor-based measuring system for the dynamics and energy of mobile machines. It was determined that the measuring systems used to study the operation of cars, tractors and machine-tractor units today are not able to measure many parameters of functioning in dynamics during the execution of technological processes in agriculture. The use of microprocessors changes the structure of the digital part of devices. Significant computing capabilities of microprocessors allow the use of more complex work algorithms. At the same time, the requirements for the analog part of the measuring device are reduced and high metrological and operational characteristics are ensured. Based on the microprocessor, a measuring system was created to determine the dynamic and traction-energy indicators of the functioning of mobile machines. The main element of this system is a computing module consisting of an STM32F407 microprocessor computing element that processes data from sensors and a microprocessor element for data collection and storage. A hard disk, solid-state drive or USB Flash drive is used as an information storage device. The computing module has a touch display for displaying parameters and controlling the measuring system, so it can be used without an external personal computer. The number and types of sensors with which the machine is equipped during testing depends on its type and parameters required for study. To determine the dynamics of the tractor or unit elements, an inertial measuring device is used, consisting of gyroscopes and acceleration sensors, the number of which depends on the number of tested elements. The measuring system of dynamic and energy parameters of tractors and machine-tractor units was used in the study of the KhTZ-242T wheeled tractor. The dependence of the traction force of the seeder and the spectral density was determined. The results of experimental studies proved the effectiveness of using a microprocessor measuring system during field and laboratory tests of tractors and machine-tractor units. Keywords: microprocessor, measuring system, tractor, experimental studies.

A portable calorimeter for measuring the calorific value of natural gas

Abstract
 Natural gas quality assessment is a relevant issue. A critical analysis of calorimeter designs for measuring the calorific value of natural gas was carried out. The most common methods for determining the calorific value of natural gas are as follows: direct by gas calorimeters; indirect by gas chromatographs; indirect, based on correlations. The advantages of isoperibolic calorimeters of measuring calorific value of natural gas directly in the consumer’s conditions are substantiated. The design of a portable calorimeter containing a thermostated shell, calorimetric tank, Peltier element with tank, circulating pump, gas burner, thermostat systems, metered supply of natural gas and air, fuel ignition, sensors, combustion analyzer and control and measurement unit, was developed. The geometric dimensions of the calorimetric tank are optimized, materials and technologies of manufacturing parts are specified. The metrological analysis of the developed portable calorimeter was carried out. A method for measuring the calorific value of natural gas directly in the conditions of household consumers and transport enterprises was developed. The results of testing the prototype calorimeter in the laboratory confirmed its high performance and metrological characteristics, and the deviation of the measurement of the calorific value of natural gas from that determined using a gas chromatograph was 0.6%.

The KIZ Infrasound Stations for Geophysics Research and Monitoring

New KIZ infrasound stations (ISs) have been produced by the Typhoon Research and Production Association (Obninsk, Russia) and operated offline over several years at several locations in Russia. All the IS components, i.e., the configuration, microbarometers, pipe arrays, the data acquisition system, the hardware box, and other parts have been developed on the basis of the experience gained in designing and operating similar systems and, primarily, the infrasound component of the International Monitoring System for monitoring nuclear test explosions. In addition to the high and stable metrological characteristics, the main advantages of these ISs are their comparatively low cost, minimum operating expenses, reliable performance in a wide range of weather conditions, and easy metrological adjustment and calibration. The KIZ ISs are adapted to the operating conditions on a territory of a typical RF weather station.

SIGNAL PHASE SHIFTS DURING THE MEASUREMENT OF VIBRATION PARAMETERS

In systems of vibration control, monitoring, diagnostics, active vibration protection, measurements and control of vibration parameters are necessary. For this, piezoelectric sensors are widely used in them as primary transducers. These sensors, due to their high metrological characteristics, such as accuracy, speed, a wide band of operating frequencies and temperatures, are traditionally used to measure vibration displacement, vibration velocity and vibration acceleration. The use of these types of sensors is necessary due to the need to measure and control vibration at objects with different frequency characteristics. The article considers possible distortions of the measured signal at the output of the sensors due to phase shifts. These phase shifts must be taken into account when developing and constructing measurement and processing schemes of the vibration signal. This is especially true when measuring and recording a rapid vibration processes, such as mechanical shock.

Measuring System for Non-Destructive Testing of Metal Rods

The control parameters of metal products using the eddy current method of nondestructive testing based on electromagnetic induction law is now widespread. Due to the high sensitivity over a wide frequency range of the ability to control the mechanical properties , uniformity of material, both magnetic and non-magnetic materials, beskonechnosti, high reliability, automation, process control, etc.
 The object of study is the process of interaction of external electromagnetic fields with defects in heterogeneity of structure in metal rod, causing a deformation of microtubuli currents and, accordingly, their influence on the inductance coil of the sensor. So, according to the law of electromagnetic induction eddy currents induced by an external electromagnetic field will be asking a private field that will oppose the external field that will lead to a change in inductance of the sensor coil. Therefore, the most informative parameter in this case is the relative change in inductance of the sensor.
 In the known designs use differential transformer sensors, transmission type, which differ in complexity of implementation, but have high sensitivity. In existing works not enough attention on improving of the metrological characteristics . Modern means of microstraava flaw detectors in the overwhelming number are for scientific research, but little attention is paid to tools that can be used in industrial processes, through a complex measurement process in the existing funds and the large volume of the software during automatic processing of information.
 In the presented work there is a system for nondestructive testing of metal bars with deprivation of the above-mentioned disadvantages, which would provide high metrological characteristics in a wide frequency range, separate measurement of impedance components of the sensor, which allows the reduction of methodological errors of determination of the main characteristics of the output signal of microstraava sensors.
 The scientific result is created sambalanco pavement system based on electronic dharamtala model of a vortex sensor with high metrological characteristics, which allows you to create real-time signal proportional to the amount of damage that will give you the opportunity to increase productivity in the quality control bar of metal products in a production environment.

TEMPERATURE INFLUENCE ON THE MAGNETIC SENSITIVE TRANSISTOR STRUCTURES PARAMETERS

Semiconductor magnetosensitive transistor structures (MTS), as investigations have shown can be the basis of effective magnetic field sensors, as well as sensors of other physical quantities. However, the practical such sensors application requires high metrological characteristics to investigate the effect of destabilizing factors on the MTS itself. Among the basic these factors is temperature. Its influence is so noticeable that the dependence of the MTS parameters on it can be used for sensors of other physical quantities. A number of papers have been devoted to the study of the temperature influence on the MTS characteristics. However, they are non-systemic in nature and differ in the results, and do not always have sufficient comparisons with the theory and explanation of the nature and mechanisms of temperature influence. This paper sets out the task of a consistent and systematic these problems study in order to optain stronger knowledge of the temperature effect on the MTS characteristics.The experimental and theoretical temperature dependences of the drift MTS (DMTS) current transmission coefficients in the magnetic field, the coordinate of the maximum mangitosensitivity site dependence on temperature, and the dependence of the DMTS mangitosensitivity on temperature for different materials are given.The mechanisms of the temperature influence on the MTS, their characteristics dependences, in particular, the conversion parameters from the point of view of possible use in sensors, are analyzed.

Електронні засоби дослідження механічних властивостей біологічних тканин

The paper shows the relevance of studying the mechanical properties of biological tissues and biocompatible materials for solving the problems of general and reconstructive surgery, transplantology, manual therapy, virtual simulation of surgical operations, robotic surgery, etc. The authors present basic information about biological tissue as an object of research and give a brief overview of the devices used for studying the mechanical characteristics of biological tissues. An experimental system for testing deformations of biological tissues and biocompatible materials during compression is described. The system is developed using modern hardware and software, as well as effective technical solutions. The results of the practical use of the developed device are presented and the obtained dependences of the mechanical stress of biological tissue samples on their deformation under pressure are analyzed. The system has high metrological characteristics and low cost, and allows performing all the necessary functions for measuring, processing and visualizing the data. The measurements obtained with this system can help form the recommendations for doctors on choosing the optimal operation mode of medical devices and instruments in each specific case. In addition, the measured data can be used to create mathematical models of biological tissues and biocompatible materials in order to further carry out virtual experiments. In further studies, the authors plan to create the mathematical models of biological tissues based on the finite element method and using the actual values characterizing the tissue, obtained with the developed system.

Control of Surface Density of Textile Materials Using Automated Scanning System

The paper demonstrates the importance of controlling the surface density of textiles, which include mainly fabrics, knitted fabrics and nonwoven fabrics, in order to improve the quality of their manufacture.
 It considers the most accurate methods of controlling surface density by determining the mass to area ratio of the textile sample. And it is also shown that, in addition to high accuracy, such met­hods have many fundamental disadvantages: the need to obtain a sample of textile material, low productivity, inability to automate the process of determining surface density, and so on.
 In addition, it deals with optical methods for controlling surface density based on the imaging of textile material and its subsequent analysis. However, the presence of factors such as entanglement complexity, the presence of pores, and some others does not fully reveal the potential of optical surface density methods.
 The paper also shows that at different points in the surface of the textile material, its surface density may differ significantly from its average value. Therefore, there is a need for an automated scanning system that allows radiating and receiving electroacoustic converters to be moved to exactly the point of the surface of the textile material whose surface density requires measurement.
 In order to solve the problem, it was proposed to use a toothed belt gear, and to drive it with the help of step motors controlled through drivers. In turn, to communicate drivers with the control computer, it was proposed to use a microcontroller with an integrated USB interface (for example, manufactured by Microchip Technology Inc.), and software for it to write in one of the high-
 level programming languages (for example, C #).
 This construction of the automated scanning system is due to the fact that the existing means of linear movement, in terms of the design of the scanning system, have a lot of redundancy: too much cost, too much accuracy, the need to use specialized software, and so on.
 The use of the proposed linear positioning means will allow the scanning system to have sufficiently high metrological characteristics at a relatively low cost.

Hydrostatic Analyzer of Hydrochloric Acid Solution

The design of a hydrostatic analyzer of hydrochloric acid (HCl) solutions with concentrations up to 40 mass% is reviewed. Its metrological characteristics are determined. The device features a simple design and has high metrological characteristics, low energy consumption, and can be used under production conditions as an alternative to other analyzers of HCl solutions.

Precision contact displacement meter

Modern machine building, instrument making, robotics, optical production, aircraft industry and other industries where mechanical devices are manufactured and used, are closely linked to the need for accurate measurement of the movement of objects and measurements of their linear dimensions. The variety of areas of use of devices for measuring linear displacements and distances, the constant growth of the requirements for the accuracy of the sensors, the range of measurable quantities, as well as the orientation to solving specific practical problems, suggest that the development and research of new meters for linear displacements and distance meters, as well as improvements of existing sensors are an important and relevant task. Practical examples of problems solved by existing meters of linear quantities are the control and measurement of the geometric characteristics of the product (dimensional measurement, dimensional deviation of form and location of surfaces); ensuring precise positioning of separate units of assembly units when they are assembled in precision instrumentation; precise positioning of moving elements, etc. Among the various technical solutions for the creation of high-precision measuring devices, the meters should be noted with the contact method of measurement and the use of inductive converters with a digital reference measurement result. Contact displacement meters using inductive sensors are characterized by the ease of production and use. They are unpretentious to the environment and have rather high metrological characteristics.

Дослідження можливості розробки фазо-частотного ультразвукового вимірювального перетворювача швидкості потоку природного газу в закритих трубопроводах малого діаметра

The article explores the possibility of developing a phase-frequency ultrasonic measuring transducer of the gas flow velocity in closed pipelines of small diameter. Analysis of modern ultrasonic flow meters shows the presence of a dead zone with a small diameter of the pipeline, which requires other solutions in the near zone, which necessitates the creation of flow meters with high metrological characteristics and a wide range of applications. A mathematical model of a phase-frequency ultrasonic transducer has been developed, in which the flow rate can be determined using four ultrasonic wave frequencies and the corresponding phase shifts of the signals at which the phase shifts lie within the number of whole acoustic wavelengths. This allows extending the working range, selecting the optimal frequency of the ultrasonic wave for the operation of the measuring transducer and increasing the measurement accuracy. Based on the proposed mathematical model, a structural diagram of a phase-frequency measuring transducer for flow velocity and measuring means for controlling natural gas consumption was developed, which contains a pipeline section, two transmitting and two receiving piezoelectric elements, two generators, two pulse shapers, two phase detectors and a microprocessor unit. To study the proposed mathematical model of the measuring transducer, an experimental setup was assembled, consisting of a signal generator, an oscilloscope, measuring sensors located on the pipeline section, and an air flow generator, which allows to obtain the dependence of the phase shift of signals on the flow velocity. The obtained experimental data indicate the prospects for the practical application of the phase-frequency method of measuring the flow rate and create an ultrasonic flow meter based on this method with high metrological characteristics, which is able to work in near-zone conditions.

Design of linear capillary measuring transducers for low gas flow rates

The performed analysis of known capillary flowmeters for low gas flows reveals the prospect of constructing the primary measuring transducers of flowmeters with a linear output signal. Owing to the stability of dimensions of the pass-through channels in glass capillaries channels such flowmeters can demonstrate high metrological characteristics. In this regard, we have investigated the capillary as a sensing element in the primary transducers of flowmeters for low gas flows.Different circuits of capillary primary transducers for the measuring instruments of low gas flow rate have been examined. Our study makes it possible to select the optimal circuit of a primary measuring transducer based on the measurement range, as well as the number and size of the pass-through channels in capillaries. For example, the flow meter based on a package of capillaries demonstrates a wider measurement range compared to other schemes.We have derived analytical dependences that enable the design of single- capillary, package, and bridge transducers. Comparative characteristics of the specified primary measuring transducers are provided. We have constructed algorithms for calculating dimensions of channels in the capillaries of transducers with a linear output signal.The influence of temperature and barometric pressure on a deviation in the static characteristic of the transducer has been estimated. It was established that the bridge circuit, unlike others, ensures partial compensation for the influence of external factors.We have designed and investigated a capillary oxygen flowmeter, constructed using the bridge measurement circuit with a linear conversion function, intended for an automated system of the manufacturing process of workpieces for fiber light guides. The upper limit of measurement by the flowmeter is at the level of 54 l/h, its basic relative error is 0.8 %

SEISMIC-ACOUSTIC WAVES OF SEISMIC VIBRATORS IN THE LITHOSPHERE-ATHMOSPHERE SYSTEM

The problem of studying the interaction of various geophysical (seismic, acoustic, meteorological) fields is considered in the context of prediction of geo-ecological risks generated by technogenic and natural phenomena. In this connection the vibration method of studying the geophysical fields offered by the authors is considered and investigated. Thanks to high metrological and ecological characteristics of seismic vibrators high accuracy and repetition of the research results in the considered sphere are achieved as well as the ecological compatibility of their acquisition. The results of the research have been substantiated both theoretically and experimentally.

Metrological Support in Technosphere Safety

The principle of metrological support in technosphere safety is considered. It is based on the practical metrology. The theoretical aspects of accuracy and errors of the measuring instruments intended for diagnostics and control of the technosphere under the influence of factors harmful to human beings are presented. The necessity to choose measuring devices with high metrological characteristics according to the accuracy class and contact of sensitive elements with a medium under control is shown. The types of additional errors in measuring instruments that arise when they are affected by environmental influences are described. A specific example of the analyzers application to control industrial emissions and measure the oil and particulate matter in wastewater is shown; it allows assessing advantages and disadvantages of analyzers. Besides, the recommendations regarding the missing metrological characteristics of the instruments in use are provided. The technosphere continuous monitoring taking into account the metrological principles is expected to efficiently forecast the technosphere development and make appropriate decisions.

Mathematical model of high-voltage instrument autotransformer intended for use in smart grid networks

The object of the research is a mathematical model of the active part of the high-voltage instrument autotransformer with several output windings. The most challenging task in this model is leakage inductance calculation of single winding turns or groups of autotransformer winding turns. Also, a significant problem when calculating the parameters of the autotransformer are those operating conditions, that are close to no-load conditions. To create a mathematical model of the active part of a high-voltage autotransformer, taking into account the leakage inductance of each single winding turn (or groups of winding turns), and also the magnitude and type of the load, it is proposed to modify the known system of transformer equations detailed to the level of single turns (or groups of turns) and use the proposed method for determining the partial self- and mutual- leakage inductances by numerical methods. With a help of the developed mathematical model of the active part of a high-voltage autotransformer, a prototype of a 10 kV autotransformer with high metrological characteristics was designed and manufactured. Positive results of metrological certification of the created high-voltage autotransformer confirmed the possibility of calculating the parameters of such primary high-voltage transformers that can be used in Smart Grid networks in conjunction with analog-to-digital converters, thus unifying the electromagnetic primary high-voltage transformers. It is shown that the operating conditions of high-voltage autotransformers, close to no-load conditions, allow easily achieve high accuracy of high voltage transformation.