Calibration Of Measuring Equipment Research Articles

Comparing measured sound strength to theory as a function of reverberation time and room volume

ISO Standard 23591 demonstrates how the sound pressure level in a room may be estimated with a knowledge of (1) the sound power of sources in that room and (2) the sound strength G of that room as defined in ISO 3382-1. In this presentation, the theory connecting room volume V, reverberation time T60, and sound strength G is summarized, and a comparison of measured sound strength G to this theory is explored for a wide range of rooms. After an explanation of the mathematical model, a description of the calibration of measurement equipment using Odeon software is discussed, including measurements taken in a reverberation chamber. A brief review of the rooms in which sound strength was measured is provided. Both measured and theoretical sound strength results are presented for the rooms reviewed. The difference between measured G and theoretical G using this mathematical model is analyzed statistically both for data measured with this test setup and with concert hall data from Beranek’s book. This model lends itself to designing rooms of appropriate reverberance and loudness for a given context, musical or otherwise.

The influence of primary measured parameters and electricity consumption in automatic solid fuels-fired boilers on the seasonal space heating energy efficiency

Commission Regulation (EU) 2015/1189 of 28 April 2015 implementing Directive 2009/125/EC of the European Parliament and of the Council with regard to Ecodesign requirements for solid fuel boilers presents the way to determine the seasonal space heating energy efficiency (ηs). These requirements are important to develop environmental-friendly sources for space heating. The value of ηs depends on (inter alia) a negative contribution to the ηs by auxiliary electricity consumption. In the current work, the analysis of sensitivity of electricity consumption measurement on ηs has been presented. The analysis includes also other specific measured parameters like water flow rate, water temperature, fuel consumption and higher heating value. Moreover, the impact of specific heat losses on the efficiency of the boiler is discussed and analyzed. The experimental and analytical investigations of 69 boilers (52 coal-fired and 17 biomass-fired) were carried out in the power range of 12–517 kW (nominal) and thermal efficiency of 83.1–96.3%. It was proved that the available relative uncertainty of electricity consumption gauge (i.e. <5%, guaranteed by suppliers) is acceptable to obtain accurate analysis. The seasonal space heating energy efficiency in automatic solid fuels-fired boilers was experimentally determined for 69 units, and the electricity consumption demand was less than 1% of nominal thermal power. The uncertainty of water temperature measurement has the strongest influence on the ηs uncertainty. The absolute uncertainty of temperature measurement at level of 5 °C caused the increase of ηs relative uncertainty to the level higher than 100%. The presented analysis has significant meaning from the practice of the ηs determination and the strategy of uncertainty budget, as well as measurement equipment calibration.

Methods to measure the radiant flux of light-emitting diodes

To measure the radiant flux of light-emitting diodes, sphere integration, goniophotometric, and pulsed methods have been considered. A convenient method to calculate the radiant flux using the indicatrix of radiant intensity and an integrating sphere design to measure the total radiant flux of light-emitting diodes with a wide angular distribution of radiation have been proposed. Moreover, the calibration of measurement equipment has been considered. The proposed methods and measurement tools help enable the measurement of the radiant flux of light-emitting diodes in the range of 1 mW to tens of watts. The measurement results are compared using different methods. A method to estimate the absolute measurement error is proposed.

Interval type-2 fuzzy TOPSIS method for calibration supplier selection problem: a case study in an automotive company

Product standardization has gained importance with the increase of customer demands and developments of technology. Products must be tested with measurement equipment to ensure quality standards. In quality management, the variability between products is targeted to be minimum. Products are produced at a target value with specific tolerance levels. Measurement equipment are used to confirm that the dimensions be in accordance with the required tolerance levels. The calibration of measurement equipment is crucial for acquiring certain measurements. The calibration process aims to minimize the measurement error by providing the accuracy of measurement equipment. The companies can carry out their calibration processes in the company structure for certain equipment. However, companies may need outsourcing for the calibration of complex equipment. This study includes a model to select the most appropriate calibration supplier by using the interval type-2 fuzzy Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method. The proposed approach is presented with a case study for torque-limiting wrench calibration in an automotive company. In the case study, ten different evaluation criteria were determined from the decision-makers and the literature for the calibration suppliers’ evaluation and selection. Within the scope of these criteria, three alternative suppliers (A, B, and C) were evaluated and supplier C was selected as the most suitable calibration supplier.

재생골재를 함유한 콘크리트의 열팽창계수 측정

PURPOSES : This study was performed to determine a systematic approach for measuring the coefficient of thermal expansion (COTE) of concrete specimens. This approach includes the initial calibration of measurement equipment. Test variables include coarse aggregate types such as natural aggregate, job-site produced recycled concrete aggregate, and recycled aggregate processed from an intermediate waste treatment company. METHODS : First, two cylindrical SUS-304 specimens with a known COTE value of . were used as reference specimens for the calibration of each measurement system. The well-known AASHTO TP-60 COTE apparatus for concrete measurement was utilized in this study. Four different measurement apparatuses were used with each LVDT installed and a calibration value was determined using each measurement apparatus. RESULTS : In the initial experimental stage, calibration values for each measurement apparatus were assumed to be almost identical. However, using the SUS-304 samples as a reference, the calibration values for the four different measurement apparatuses were found to range from 3.49 to . Using different adjusted values for each measurement apparatuses, COTE values for the three different concrete specimens were obtained. The COTE value of concrete made with natural coarse aggregate was , that of job-site produced recycled coarse aggregate was , and that of recycled aggregate processed from the intermediate waste treatment company was . CONCLUSIONS : We observed that the COTE value of concrete made from recycled concrete aggregates (RCA) was higher than that of concrete made from natural coarse aggregate. This difference is due to the fact that the total volumetric mortar proportion in the RCA mix is higher than that in the concrete mix made with natural coarse aggregate.

Implementation of Confirmation of Methods in Measurement Equipment Calibration as a Normalized Strategy to Ensure the Quality of Measurements Made in the Construction, Repair, and Modernization of Ships and Naval Artifacts in COTECMAR

The naval, maritime and riverine industry is one of the sectors, which has greater contribution to theworld economy, hence, quality assurance is one of the main priorities in all maritime activities, especiallythe ones related to ship building. The monitoring of different variables that allows good performance of aship involves assessing equipment in order to assure data taking with greater precision and accuracy; thisis where metrology takes place as a science for studying inherent problems to measurement data collection,focusing on equipment calibration. The grade of uncertainty produced by data taking procedures of eachequipment on board of ship depend on techniques and results control specifications, which are knownas Methods Confirmation. The metrology laboratory at COTECMAR applied this method to guaranteequality by estimating validity and reliability of the obtained results through different measuringequipment related to ship construction and repairing.

The Electrochemical Principle of Measuring Underwater Electric Field

Whether electric stealth ship, or ship by ship to achieve the electric field detection, location can’t be separated to provide high-precision measuring equipment field measured data, underwater electric field to discuss the principle of electrochemical measurements and underwater electric field measurement equipment calibration, field measurements of underwater deep understanding of electrochemical principles and calibration of measuring equipment underwater electric field can improve the accuracy of the electric field experiments, and finally according to proposed calibration method, calibration of measuring equipment of a type of electric field.

Electric Field Distribution Measurement Equipment Calibration Based on Electric Field Calculation of Space

Electric Field Distribution Measurement Equipment Calibration Based on Electric Field Calculation of Space

Remote calibration of ionization chambers for radioactivity calibration

A new calibration technique, referred to as e-trace, has been developed by the National Institute of Advanced Industrial Science and Technology (AIST). The e-trace technique enables rapid remote calibration of measurement equipment and requires minimal resources. We calibrated radioisotope calibrators of the Japan Radioisotope Association (JRIA) and the Nishina Memorial Cyclotron Center (NMCC) remotely and confirmed that remote calibration provided results that are consistent with the results obtained by existing methods within the limits of uncertainty. Accordingly, e-trace has been approved as the standard calibration method at AIST. We intend to apply remote calibration to radioisotope calibrators in hospitals and isotope facilities.

Final report on comparison EURO.QM-S1: Automotive exhaust gas

Automotive gas mixtures of carbon monoxide, carbon dioxide, oxygen and propane in nitrogen are used for the calibration of measurement equipment for automotive exhaust gases. This comparison involved four laboratories. Two have used their own gravimetric primary standards, one of them used standards prepared by an accredited laboratory and the other used their own gravimetric primary standards together with gravimetric primary standards prepared by other national laboratories.CEM operated as the coordinating laboratory in this comparison. The selected primary gas mixtures for this comparison were individually prepared gravimetrically and thoroughly studied for their chemical composition and stability.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by EUROMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Uncertainties in EMC compliance testing

After an EMC compliance test has been successfully applied to an equipment and the test engineer declares that this equipment does or does not comply with the specified requirements, a relevant question seems to be 'How certain is this test engineer that indeed the equipment does or does not comply with the requirements?' In other words: 'What uncertainties play a part in EMC compliance testing and what is-with a certain level of confidence-the magnitude of the associated compliance uncertainty?' Important contributors to this uncertainty are given together with illustrative examples. These contributors include aspects of the way the (standardized) EMC test is formulated, measuring equipment tolerances and calibration, EMC test-engineer skill, and traceability of the (standardized) EMC compliance test. Some consequences for today's EMC standards, and the writers of EMC standards are discussed. Incorporating EMC compliance uncertainty in a compliance criterion is only possible after improving the traceability of the EMC standards, the formulation of the specifications, the calibration of measurement equipment and description of test set-ups. Also a sound estimate of the maximum allowable compliance uncertainty is needed.

A method for precise RF admittance measurement

An improvement in the theory of the dual admittance bridge with self-calibration ability for precise RF measurement is described. The approach to the bridge function analysis extends utilization of its high resolution and accuracy in immittance standardization into the UHF range. No detailed information about the bridge's internal structure is needed for the theory, which describes it as a multiport device. Thus, the theory has not only contributed to bridge arrangement, but also enables simple and efficient calibration of measurement equipment based on the classical twin-T admittance bridge. Improvement in the accuracy and frequency range of the calibrated equipment should be expected. The theory has been verified on a special coaxial bridge circuit at 100 and 1000 MHz. >

Calibration systems for laser power or energy measuring apparatus.

Calibration of laser measurement equipment requires the use of an accurate and stable source of power. Lasers are not generally suitable for this purpose. The Bureau of Radiological Health, Food and Drug Administration, has been supplied with two National Bureau of Standards C-Series Calorimeters which rely upon high accuracy D.C. electrical power substitution as a calibration reference. The NBS-supplied system is discussed. An alternate, moderate cost commercial electrical substitution calorimeter system is discussed with respect to its applicability and accuracy when performing laser measurement equipment calibration.

Bioimpedance spectroscopy and dielectric properties of biological tissues

Event Abstract Back to Event Bioimpedance spectroscopy and dielectric properties of biological tissues Igor Lackovic1* 1 University of Zagreb, Faculty of Electrical Engineering and Computing, Netherlands Aim: For accurate forward and inverse modelling in EEG and MEG head tissues dielectric properties are of utmost importance. The purpose of this presentation is: (i) to give an overview of impedance spectroscopy, a powerful method for characterizing dielectric properties and (ii) to present a survey of dielectric properties of various tissues. Methods: Biompedance spectroscopy, which is measurement of dielectric properties (electric conductivity and permittivity) as a function of frequency, requires special attention and careful calibration of measurement equipment. To interface the instrument (LCR bridge, impedance analyzer, network analyzer) to biological sample, various configurations of electrodes, impedance cells and open-end coaxial probes are used. When measuring dielectric properties at low frequencies (up to a few kHz) electrode polarization is the main problem since electric double layers that form at the electrode-electrolyte interface cause large capacitance which has to be corrected for. Electrochemical processes at electrodes are very complicated and depend on electrode material, state of electrode surface, current density, etc. On the other hand, biological tissue, as a measurement object, is very complex in terms of conduction/polarization mechanisms and is generally inhomogeneous (properties vary with space coordinates), anisotropic (properties are different for different directions of propagations), dispersive (properties depend on the frequency of the field) and nonlinear (properties depend on the intensity of the field). At low frequencies biological tissue is predominantly an electrolytic conductor since there are always free ions to migrate. At the same time, biological tissue, due to its complex structure, exhibits in the presence of electric field characteristics of dielectric materials such as polarization. Besides, tissue electrical properties are temperature dependent. Moreover, pathological processes (e.g. tumours) can alter tissue electrical properties. Additionally, as measurements cannot always be performed in vivo post-mortem tissue changes should also be considered. Results: Based on our experimental studies and literature data we illustrate all the above mentioned tissue characteristics (inhomogenity, anisotropy, dispersions, nonlinearity, post mortem changes etc.) and factors affecting accuracy of conductivity and permittivity measurements. We also present results from literature survey on various head tissue conductivities. Apart from results obtained by bioimpedance spectroscopy, which is the main focus of this presentation, we also cover recent magnetic resonance electrical impedance tomography (MR EIT) studies for imaging head tissues conductivity distribution. Conclusion: Results of this presentation may carry important information for EEG/MEG source imaging since accurate solution of EEG/MEG inverse problem depends on accurate values of head tissues conductivities. Conference: NeuroMath COST Action BM0601: Neurodynamic Insight into Functional Connectivity, Cognition, and Consciousness, Dubrovnik, Croatia, 27 Mar - 28 Mar, 2010. Presentation Type: Oral Presentation Topic: Talks Citation: Lackovic I (2010). Bioimpedance spectroscopy and dielectric properties of biological tissues. Front. Neurosci. Conference Abstract: NeuroMath COST Action BM0601: Neurodynamic Insight into Functional Connectivity, Cognition, and Consciousness. doi: 10.3389/conf.fnins.2010.05.00004 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 24 Jul 2010; Published Online: 24 Jul 2010. * Correspondence: Igor Lackovic, University of Zagreb, Faculty of Electrical Engineering and Computing, Atlanta, Netherlands, igor.lackovic@fer.hr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Igor Lackovic Google Igor Lackovic Google Scholar Igor Lackovic PubMed Igor Lackovic Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.