STRUCTURAL AND PARAMETRIC OPTIMIZATION OF GAS-HYDRODYNAMIC MEASURING TRANSDUCERS OF PHYSICAL AND MECHANICAL PARAMETERS OF FLUIDS

The article is devoted to improving the methods for building throttle diagrams of gas-hydrodynamic measuring transducers of physical and mechanical parameters of fluids. The authors reviewed modern throttle transducers of various parameters, built on different diagrams, with different numbers and types of throttle elements, with different output signals. We established that the goodness of the measuring transducer is determined both by the structural diagram and the design characteristics of the throttle elements of a specific measuring diagram. The article proposes using structural synthesis with parametric optimization to achieve the specified characteristics of the gas-hydrodynamic transducers. The aim is to develop an effective method for building throttle diagrams of gas-hydrodynamic measuring transducers of physical and mechanical parameters of fluids using structural optimization of diagrams and to evaluate each dia-gram using parametric optimization methods with the appropriate criterion that quantifies the goodness of the measur-ing transducer. To achieve this goal, the authors analyzed the criteria and resources of structural and parametric optimization of gas-hydrodynamic transducers. In particular, the following resources of structural synthesis of measuring transducers’ dia-grams are analyzed: diagram order and throttle arrangement, type of throttles, output signals, supply mode of the transducer. Approaches to parametric optimization of throttle diagrams are offered: based on the mathematical model, one defines the objective function, forms restrictions on variable and fixed values, substantiates optimization parameters, chooses the optimization method. As a result of the research, the authors developed a technique for structural and parametric optimization of gas-hydrodynamic measuring transducers, making it possible to synthesize throttle diagrams and build mathematical models of transducers of specific parameters of the fluid with optimal characteristics.

Monitoring System of Vibroacoustic Parameters of a Working Zone

This article discusses the safety problems of the use of aviation technology associated with the influence of operational vibration of aircraft. The topical issue of timely detection and prevention of a dangerous state of critical machines and mechanisms is analyzed. Modern means of measuring vibration parameters, principles of measurement, as well as characteristics of the sensitive element of the measuring transducer, are considered. The block diagram and operation algorithm of the proposed system for monitoring vibroacoustic parameters, which is built on the basis of a piezoelectric transducer, is presented. This system can measure the parameters of noise and vibration and analyze the measured data, signal about exceeding the permissible ranges for human work, display the measured data. The advantage of the proposed system is the connection of the measuring channels with the mainboard using the Bluetooth module, which allows the sensors to measure noise and vibration to be placed in any part of the working area.

Simulation modeling of composite piezotransformer measuring transducer with differential output

The article presents the results of using simulation modeling to study the output characteristics of composite piezotransformer measuring transducers with a differential output. The processes were simulated using the Micro-Cap software. The article presents options for controlling the parameters of the equivalent electrical circuit of the converter. The article presents the results of simulation of composite piezotransformer measuring transducers with two degrees of freedom. Structurally, they can include piezoelectric elements, additional vibrators and communication elements between them. This allows you to expand their functionality, scope of practical application. The advantages are applicable to work in difficult and even extreme conditions. On the basis of such measuring transducers, prototypes of highly sensitive sensors were developed for measuring pressures, forces, temperature and other physical quantities, for monitoring the physical and mechanical characteristics of solids, liquid and gaseous media.

Research and Development of Metrological Assurance Elements for Leeb Hardness Measurements

This article is devoted to contemporary topics of ensuring the uniformity of Leeb hardness measurements. The analysis of the physical principles of the Leeb hardness test is carried out, and the influence of the measuring transducer parameters on the measurement results is investigated. A four-level structure of the calibration hierarchy for the Leeb hardness scales is proposed, which ensures metrological traceability of hardness scales from the calibration reference machines (CRMs) to measuring instruments. A list of requirements for the 2nd grade CRM and the 2nd grade Leeb reference test blocks are formulated in accordance with the proposed calibration hierarchy draft and their values are calculated. A prototype was developed and a model of the 2nd grade Leeb hardness CRM and a set of Leeb reference test blocks were manufactured, as well as the compliance of their metrological characteristics with the requirements of the proposed calibration hierarchy draft and international standards was confirmed. The results of this work allow us to ensure the uniformity and reliability of the Leeb hardness measurements.

Some features of the development of a deformation frequency- response vacuum gauge for measuring low absolute pressures

The article shows the tasks involved in developing a deformation frequency-response vacuum gauge for measuring low absolute pressures. The calculations of the parameters of the measuring transducer are given, which made it possible to create a competitive and inexpensive device.

IMPROVING THE ACCURACY OF VIBRATION MEASUREMENT RESULTS

The current state of control of vibration measuring equipment is studied in the work, the analysis of technologies of control of vibrating measuring machine equipment is carried out. It is determined that during the control a sufficient requirement for the analysis of changes in the state over time is to conduct periodic vibration measurements in the same modes of operation of the object. Therefore, the urgent task is to increase the reliability and accuracy of measurement results. It can be enhanced by obtaining additional information. For this purpose, recommendations for optimizing the vibration control points of the mechanism are formed. To increase the accuracy of measurement results when controlling the equipment for vibration signals, the methods of mounting the measuring transducer in the equipment monitoring system are considered. It is shown that the method of mounting the measuring transducer can affect the results of vibration measurements.

Method of modeling the electrical capacity of the measuring transducer

To diagnose the eccentricity of the rotor shaft of an electric machine, a device is proposed, the sensitivity of which does not depend on fluctuations in the parameters of the network and the load of the electric machine, since the displacement of the rotor is monitored using capacitive sensors located evenly around the circumference of each end of the shaft. Diagnostic results are assessed according to two valid criteria. The device allows to determine not only the value of the eccentricity of the rotor, but also the direction of the displacement of the rotor. Keywords: electric machine, rotor eccentricity, method for modeling electrical capacity. [email protected]

DEVELOPMENT SHAFT RUN-OUT MEASUREMENT TRANSDUCERS FOR POWERFUL GENERATORS FAULT CONTROL SYSTEM WITH CAPACITIVE COPLANAR CONCENTRIC SENSOR

The paper presents the results of the study of a capacitive radial beating sensor, consisting of a primary transducer with concentric coplanar electrodes and a secondary measuring transducer «capacitance - voltage». The design and results of calculations of the capacitive sensor conversion function presented. The parameters of the circuit of the secondary measuring transducer based on the frequency-independent measuring circuit are determined. The optimal frequency range for measurements selected.

CALCULATION OF THE BASIC AND ADDITIONAL ERRORS OF THE MOISTURE METER OF GRAIN AND GRAIN PRODUCTS

Calculation of the basic error of the moisture meter is determined by the error in measuring the frequency. The latter, in turn, consists of the error of the timer-counter when counting the frequency (quantization), the error in determining the coefficients a1and a2of the mathematical model of the measuring transducer during calibration, and the error due to the noise of the comparator-amplifier.Keywords:error, error calculation, measurements, result.