INDUCTIVE PARAMETRIC EDDY-CURRENT TRANSDUCER (IPEP) FOR MEASURING ELECTRICAL AND TEMPERATURE PARAMETERS OF WASTEWATER FROM BREWING PRODUCTION

The possibility of using the theory of operation of a differential inductive parametric eddy-current transducer (IPET) for measuring the electrical and temperature parameters of a sample of acidic and alkaline wastewater is investigated. The need for the development of new informative methods for measuring the physicochemical parameters of wastewater is proved, in the realization of which a promising method of purification is selected. On the basis of a differential scheme for switching on two parametric converters: with exemplary purified water and a converter in which a test tube with a sample of waste water from a brewing production is placed, a differential informative method for measuring the electrical and temperature parameters of the liquid under study is proposed, which is based on the analysis of the components of the difference signal of phase shift angles measured electrical components of the switching circuit signals. The basic relationships that describe the operation of the IPET with the sample of the controlled liquid are given. The scheme of switching on differential IPET with a liquid sample, which is placed in a glass test tube, is considered; the differential scheme provides for heating the sample during measurements to simulate the production conditions of brewing production. Universal transformation functions are given that relate the components of the IPET signals with the specific electrical conductivity χt.s. and the temperature t of the wastewater sample from brewing production, that is, the dependence of the phase difference signal Δj on the generalized parameter A and the dependence of the absolute increment in the specific electrical conductivity Δχ on the temperature t of the wastewater sample, in the investigated temperature range.

IDENTIFICATION OF DEFECTS SIZES EDDY-CURRENT CONTROl

A method is proposed for identifying the size of defects during eddy testing, which reduces the zones of uncertainty caused by errors in calculation and experiment. In order to reduce the uncertainty, as a criterion for comparing the theoretical and experimental dependences of the signal on the defect, one can use the difference in minimization of the squares of the deviation of the corresponding dependences. Using the method of simulating the signal of an eddy current transducer (ECP) from a defect, experiments were carried out in order to verify the method for identifying a characteristic size, a defect, with subsequent calculation of the customer’s risk.

Application of an Ultra-Compact Eddy-Current Transducer for Investigation of Defects in Welded Joints of High-Strength Steel

This article discusses the results of work on the creation of a flaw detection unit, which is focused on the study of high-strength steels. Welded joints of transformer tanks, which are made of steel grade 08G2B, were selected as the object of research. We chose this grade because of the ultra-low carbon content of this material. This opens up opportunities for the application of eddy current nondestructive testing methods. For practical measurements, a scanning device was designed and optimized. It includes a converter that uses the principles of eddy currents and includes three coils assembled on a ferrite core, grade 80NMZ. The device was tested on samples with model continuity defects (cracks and holes). Also, within the framework of the publication, modeling of corrosion defects in welded joints was carried out.

Experimental Studies of Conductive Paths of Printed Circuit Boards by Using Subminiature Eddy Current Transducers

This paper describes the development and experimental study of a software and hardware complex designed for studying the conductive tracks of printed circuit boards. In the course of this development, a subminiature eddy-current transducer and a measuring system capable of performing measurements using the newly developed transducer were created. The paper contains descriptions of the main parameters of the developed measuring system, and also presents the results of experiments conducted with various printed circuit boards, both with defect-free and those with artificial model defects. These experiments made it possible to confirm the possibility of using the developed measuring system and eddy-current transducer for controlling the conductive tracks on printed circuit boards and determining their quality.

CLUSTER ANALYSIS FOR DETECTING GROUPS OF DEFECTS ROTARY SUPPORT SYSTEM

Cluster analysis is widely used in the machine diagnostic and monitoring field. This article discusses the issue of recognizing the states of rotary-support systems with fluid-friction bearings. An experiment was carried out to investigate the effect of tightening the bolts that connect rotor-support unit body to the frame; to investigate the effect of tightening the bolts that connect electric motor to the frame; to investigate the rotor imbalance, as well as a combination of these factors. Cluster analysis based on the K-means method was applied. The readings of the eddy- current transducer were used as an input data for training. Analysis of the results revealed two groups of defects. During testing, the accuracy of group identification was 100%.

Scanning the steel 08G2B using superminiature eddy current probe

The article describes a hardware and software complex designed for defectoscopy and study of material properties. Sections of high-strength steel 08G2B pipes were scanned in the course of the research. The purpose of this study is to determine dependency of eddy current sensor signal and mechanical and operational properties of the base metal (K65 steel grade) and demonstrate the ability of developed eddy current probe to detect continuity defects and corrosion in this type of metal. The steel is ultra-low-carbon, which makes it possible to study their properties using the eddy current method. The eddy current method is a non-contact one being used both for cracks identification and determination of their characteristics. A special superminiature eddy current probe was developed, which includes three coils - stabilizing, measuring and exciting. The coils were placed on a pyramid-shaped core made of alloy 81NMA. The eddy-current transducer runs under the control of the developed hardware-software complex with a system for suppression of noise and amplification of signal received from the eddycurrent transducer. Signal processing makes it possible to separate the effects of closely spaced cracks on the eddy-current transducer signal and evaluate the contribution of each crack separately. As a parameter containing information about the presence of defects in the object of control, the voltage arrived at the measuring coil of the eddy current probe signal was used. The work studied sections of pipes with model continuity defects – cracks and holes. A research that allows to simulate the presence of corrosion in the metal was also conducted. The extreme values of the eddy current probe signal over defects of different types are obtained at various velocity, that allows to identify the type of defect, while changing the frequency of the signal on the probe allows to determine the depth of the defect.