Level gauges. Application features

This paper considers various aspects of application of the most common types of level gauges – magnetostrictive, servo-driven, radar and reflex. Much attention is paid to accuracy of level gauges, expressed in error and uncertainty, including those referred to the legally regulated measuring instruments. Due to the fact that the most of the level gauges are installed on tanks, the requirements for them, given in the standards, and possible ways to improve the accuracy of level gauges installed on tanks have been analyzed. Methods of verification and calibration of level gauges are considered, including both verification on standard units using water, and carried out by the simulation method. The requirements for the metrological control of level gauges with moving parts are stated. It is shown that for verification of such level gauges, it is necessary to carry out measurements when the water moves both up and down. However, there is no need to take measurements, as in determining the variation, at the same points when the water moves up and when the water moves down. Some known caution is needed when using the results of the verification of level gauges by the simulation method. Especially big differences in the results of verification on the standard unit with water and the simulation method are observed for magnetostrictive level gauges. This difference is due to the fact that in these level gauges, the float slides along the pipe with a certain friction, and in the simulation method, the float moves by hand and its movement does not depend on friction.

Analysis of automation technology for quality management of surface layer during turning

Quality management of the surface layer during turning is one of the most relevant areas today. Study relevance is related to the fact that automated control is a promising strategy for manufacturers in the modern world. Automated tools improve the quality of products, as well as stimulate emerging innovations and eliminate gaps in existing production skills. Automated quality management of the surface layer during turning has been examined. The sub-tasks of this work are to study the main advantages of using metrological control devices, to prove the advantages of automated quality management of the surface layer during turning on a particular example, as well as to study the main terms and definitions. One of the main methodologies is theoretical research, as well as analysis of domestic and foreign publications related to a given topic. As a result of this study, imperfection proofs of modern technical means of non-automated quality management of the surface layer during turning are presented. Relevance and advantages of using the automated quality management technologies of the surface layer during turning are discussed.

Particularities of metrological control of non-contact systems for measuring the geometric dimensions of metal products.

OJSC “BSW–Management Company of the Holding “BMC”, non-contact systems for measuring the outer diameters of products are widely used for measuring geometric dimensions. Diameter measurement systems are used to obtain reliable, true and accurate measurements. The method that provides continuous and non – contact control of these systems is the light -and – dark method of measuring the diameter.To ensure the reliability of the measurement results, the diameter measurement systems must undergo metrological control – calibration. Calibration is carried out according to the developed methodology, which specifies the order of work, requirements for standards, processing of measurement and evaluation results, and registration of calibration results. To assess the extended uncertainty, a mathematical model is created that takes into account all the corrections that affect the result of the assessment, each of which is subjected to a thorough analysis.Calibration of diameter measurement systems allows to evaluate their real deviations in operating conditions, which allows to ensure the accuracy and reliability of measuring the geometric dimensions of metal products at all stages of its production.

NORMALIZATION OF THE PERMISSIBLE ERROR AND THE CHOICE OF MEASUREMENT TOOLS FOR CONTROLLING DEVIATIONS IN THE SHAPE AND LOCATION OF SURFACES

The reliability of repaired engines is determined by many factors, among which the accuracy of the geometric parameters of engine parts plays an important role. Errors in the shape and location of the surfaces of parts cause additional acceleration of moving parts and reduce the accuracy of kinematic pairs. Violation of the movement kinematics of parts leads to a deterioration in the technical performance of the engine. In this regard, increasing the level of metrological control of shape deviation and surface location is one of the ways to improve the quality of engine repairs. Analysis of the measurement tools recommended in the reference literature has shown that they were chosen irrespective of the controlled values and without taking into account the type of measurement. The purpose of this study is to develop recommendations for improving metrological control of deviations in the shape and location of surfaces of parts during engine repairs. The paper provides theoretical grounds for choosing the criteria for selecting measuring instruments to control deviations in the shape and location of the surfaces of parts, taking into account the relevant formula. The result of indirect measurement and the measurement error (deviation of the shape and location of the surfaces of parts) are considered random values functionally related to the measured values (diameters of a part). The limits of permissible measurement errors and measurement tool errors are determined to control the deviation of the shape and location of the surfaces of new engine parts and parts subject to troubleshooting. The authors have carried out a comparative analysis of the obtained values with the error values of measuring instruments recommended in the reference literature. It has been established that most of the recommended measuring instruments have an error greater than the allowed measurement error. To reduce the risk of accepting parts that exceed the deviation norms relating to the shape and location of surfaces, it has been suggested using special criteria when selecting measuring instruments.

Design of Industrial Standards for the Calibration of Optical Microscopes

One of the most important fields of study in material science is surface characterization. This topic is currently a field of growing interest as many functional properties depend on the surface texture. In this paper the authors, after a short a review of different methods for surface topography characterization and the determination of the traceability problems that arise in this type of measurements, propose four different designs of material standards that can be used to calibrate the most common optical measuring instruments used for these tasks, such as measuring microscopes, metallurgical microscopes, confocal microscopes, focus variation microscopes, etc. The authors consider that the use of this type of standards (or others similar to them) could provide a step forward in assuring metrological traceability for different metrological characteristics that enables a more precise measurement of surface features with optical measuring instruments. In addition, authors expect that this work could lay the groundwork for the development of custom standards with specialized features tuned to gain a better metrological control when measuring specific geometrical surface properties.

Application of Metrological Approaches in the Design of Calibration Equipment for Verification of Float Level Gauges

The paper deals with a scientific approach for an increase of accuracy of measurement and possibilities for automation of the standard equipment for calibration and verification of float level gauges. They are applied in high-capacity fuel storage tanks, and they are intended to measure the level of stored liquid hydrocarbons. In the submitted paper, we describe original approaches towards metrological control of float level gauges. Firstly, we present and describe the current ways of control by means of the standard equipment of the first generation with a precision caliper and manual measuring wire with the application of modern scientific and developing processes. A new system, whose design is based on research and development, represents a fully automated measuring system which utilizes the incremental optical encoder with a precision graduated ring and a rewind pulley. The paper deals with the issue of a design of the standard equipment and its measurement system from the standpoint of metrology and construction. Based on scientific procedures, we solve reasons of errors in measurement and their reduction on concrete components of the measurement system. The result is that, following the scientific approach and mathematical description of the determination of measurement uncertainties, constructors are able to design suitable tolerances for the production of components of measuring devices and related materials and technologies.

Measuring instruments metrological monitoring in a medical organization based on a process approach

A model of the process of metrological control of measuring instruments is presented. The model includes 6 or9 stages, depending on the results of metrological control. Based on the list of measuring instruments, a contract is concludedfor metrological control. After the conclusion of the contract, the collection of documents necessary for verification iscollected. Further, the measuring instruments are transferred to an accredited organization. An accredited organization carriesout verification. If, according to the results of verification, the tool is deemed suitable for use, then the stage of obtainingconfirmation of the verification is carried out. The output at this stage will be a verification certificate. If, according to theresults of verification, the measuring instrument is not suitable for operation, then the stage of canceling the verificationcertificate is carried out. The next steps in this case are to receive notice of unsuitability for use and write-off of the measuringinstrument. At this process is considered complete. The target indicators (indicators) of the process are: the measurementerror of specific measuring instruments within the established limits. Monitoring (control) of the process is carried out bya metrology engineer of a medical organization. Control methods are: control of the calibration intervals of measuringinstruments. The model is recommended as a model for use in medical organizations. The use of this model in the presenceof a target indicator (indicator) of the process of metrological control will ensure the necessary quality of metrological workin a medical organization within the framework of the internal quality control system.