scholarly journals Level gauges. Application features

2021 ◽  
pp. 38-42
Author(s):  
Gennadiy Narodnytskyi ◽  
Evgeniy Suhomlinov ◽  
Svitlana Tiupa ◽  
Oleksandr Marchenko
Keyword(s):  
Simulation Method ◽  
Measuring Instruments ◽  
Standard Unit ◽  
Metrological Control ◽  
Moving Parts

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.

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

2021 ◽  
pp. 51-57
Author(s):  
Oleg A. Leonov ◽  
◽  
NINA ZH. SHKARUBA ◽  
LAVRENTIY A. GRINCHENKO ◽  
◽  
...  
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Indirect Measurement ◽  
Measurement Tool ◽  
Measuring Instruments ◽  
Shape Deviation ◽  
Technical Performance ◽  
Measurement Tools ◽  
Surface Location ◽  
Metrological Control

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.

scholarly journals Procedures for Assessing the Conformity of Measuring Instruments — Structure, Design Principles and Approaches to Their Choice

2019 ◽  
pp. 56-61
Author(s):  
S. Cherepkov ◽  
V. Dulya ◽  
V. Maliavskyi
Keyword(s):  
Practical Interest ◽  
Metrological Certification ◽  
Structure Design ◽  
Assessment System ◽  
Conformity Assessment ◽  
Measuring Instruments ◽  
Assessment Procedure ◽  
Metrological Control ◽  
Assessment Procedures ◽  
Selection Of

Since January 01, 2016, new legislation in the field of metrology came in force in Ukraine. There have been significant changes in the regulation of metrological activity in accordance with the new Law of Ukraine “On Metrology and Metrological Activity”, which is harmonized with European legislation, in the country. Thus, the new Law lacks such forms of metrological control as state acceptance tests and state control tests, as well as state metrological certification of measuring instruments. Instead of these types of metrological control the conformity assessment system of measuring instruments according to established requirements has been implemented. Therefore, this article considers new approaches of the conformity assessment system of measuring instruments according to established requirements and is a logical continuation of an article published in Metrology and Instruments journal (1 (69), 2018), which considered the basics of development and operating the conformity assessment system of measuring instruments. This article considers some issues related to conformity assessment procedures. Criteria for the selection of modules for the conformity assessment procedure and their description are defined. The existing approaches for selection of conformity assessment procedures of measuring instruments and the cooperation of manufacturers (suppliers) of measuring instruments with designated conformity assessment bodies on the market are given. The article offers practical interest for manufacturers of measuring instruments for the legal regulated sphere.

scholarly journals Development of a system to increase the legal metrological control of measuring instruments in Brazil

2014 ◽  
Vol 5 (3) ◽  
pp. 304 ◽  
Author(s):  
A. Soratto ◽  
O. Pohlmann Filho ◽  
M.R. de Paiva ◽  
R.B. Giordani ◽  
C. Bringhenti
Keyword(s):  
Measuring Instruments ◽  
Metrological Control

scholarly journals Design of Industrial Standards for the Calibration of Optical Microscopes

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 29
Author(s):  
Alberto Mínguez Martínez ◽  
Cecilia Gómez Pérez ◽  
David Canteli Pérez-Caballero ◽  
Laura Carcedo Cerezo ◽  
Jesús de Vicente y Oliva
Keyword(s):  
Surface Characterization ◽  
Precise Measurement ◽  
Metrological Traceability ◽  
Measuring Instruments ◽  
Fields Of Study ◽  
Optical Measuring ◽  
Metrological Control ◽  
Focus Variation ◽  
Industrial Standards

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.

scholarly journals Surface and New Building Deformation Analysis of Deep Well Strip Mining

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yuanzhong Luan ◽  
Yue Dong ◽  
Yanhe Ma ◽  
Liyuan Weng
Keyword(s):  
Surface Deformation ◽  
Simulation Method ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Measuring Instruments ◽  
Strip Mining ◽  
Deep Well ◽  
Mining Depth ◽  
Mining Width ◽  
New Buildings

Aiming at the problem of surface movement and long-term stability of a work plane of deep well strip mining in Shandong Province, an observation station is set up on the surface of strip mining, and the surface deformation value during strip mining is measured with advanced measuring instruments; on the stable surface of the old mining area, the surface deformation monitoring work is also carried out for new buildings. In addition, the FLAC3D simulation method is used to determine the subsidence factor of different mining depth, mining width, mining length, and mining thickness, and the mathematical model between the subsidence factor and mining depth, mining width, mining length, and mining thickness is established. After the surface of the old goaf is basically stable after strip mining, the high-rise buildings are built. By changing the size of the new buildings and the amount of the load imposed on the surface, the surface deformation is simulated and calculated, and the relationship between the different load positions, load sizes, loading building sizes, and the surface activated deformation is obtained. The measured value of the surface deformation confirms that the load of the new buildings can induce the activation of the old goaf and make the surface generate secondary deformation, but the activated deformation makes the new building within the range of 1, so the new building is safe.

scholarly journals Legal Metrology and System for Calibration and Verification of the Radar Level Sensors

2016 ◽  
Vol 20 (1) ◽  
pp. 95 ◽  
Author(s):  
Jaromír Markovič ◽  
Jozef Mihok ◽  
Stanislav Ďuriš ◽  
Zbyněk Schreier
Keyword(s):  
Measurement Accuracy ◽  
Practical Knowledge ◽  
Research Work ◽  
Measuring System ◽  
Measuring Instruments ◽  
Legal Metrology ◽  
Research Activities ◽  
Normative Requirements ◽  
Practical Performance ◽  
Metrological Control

<p><strong>Purpose:</strong> The paper deals with the legal metrology that is principally responsible for assuring the uniformity and correctness of measurements and presents the results of the scientific and research work in the cross-disciplinary fields. The design of the new measuring system for the verification of the radar level gauges. <br /><strong>Methodology/Approach:</strong> The requirements on performing verification of the measuring instruments are changed significantly, especially the requirement for reducing the time necessary for putting the measuring instruments out of service. Slovak legal metrology (SLM) has developed a number of its own systems for verification of the legally controlled measuring instruments. <br /><strong>Findings:</strong> The paper presents the results of the research activities aimed to refine and improve metrological continuity and metrological control of selected types of measuring instruments.<br /><strong>Research Limitation/implication:</strong> This paper are based on the theoretical and practical knowledge from the field of metrology, the analysis of the legislative and normative requirements on the measuring instruments metrological assurance, and knowledge gathered during the practical performance of the measuring instruments metrological control. <br /><strong>Originality/Value of paper:</strong> In the paper, there are presented those results of solving the tasks in the research and development fields that lead to the higher measurement accuracy, and to the elimination of the undesired influences that may occur during a measurement.</p>

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

2020 ◽  
Vol 22 (2) ◽  
pp. 138-141
Author(s):  
S. A. Mendel
Keyword(s):  
Process Approach ◽  
Internal Quality ◽  
Measuring Instruments ◽  
Control Methods ◽  
Medical Organization ◽  
Target Indicator ◽  
Metrological Control ◽  
To Receive ◽  
Metrological Monitoring

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.

Concept of a new PZT

1978 ◽  
Vol 48 ◽  
pp. 271-278
Author(s):  
Chr. Kühne
Keyword(s):  
Mirror System ◽  
Measuring Instruments

The PZT according to MARKOWITZ, undoubtedly one of the most accurate measuring instruments, has become an integral part of astronomy in the last years. Yet there are two reasons why I still tried to improve the MARKOWITZ basic idea.For the MARKOWITZ process the use of a lens objective is imperative. Because of the diameter limitations of the lens objectives the magnitude is reduced. Although a 65 cm PZT has been put into operation in Washington recently, the thermal difficulties encountered made it necessary to control the temperature actively. In addition, the 65 cm diameter of a lens equipped with 4 elements can be considered as the very limit, but not for a mirror system.In addition there are still more disadvantages using lens objectives. The useable field is restricted by astigmatism, reducing the range of declination. The transmission, especially in the blue wavelengths, decreases very rapidly with the thickness of lenses. For large multilens objectives the transmission is less than for a mirror system.

Power of Modified Brown-Forsythe and Mixed-Model Approaches in Split-Plot Designs

Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero
Keyword(s):  
Repeated Measures ◽  
Statistical Power ◽  
Mixed Model ◽  
Covariance Structure ◽  
Simulation Method ◽  
Future Research ◽  
Repeated Measures Design ◽  
Fixed And Random Effects ◽  
Split Plot ◽  
High Level

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.

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