J.A. Cruz, R.R. Machado, S.P. Oliveira. A.R. Martins, A.C. Vidal, J.A.S. Pereira, I. Caminha, I. Abud , C. Barbosa
In the present work, part of a large project, developed in partnership among INMETRO, ITUC/PUCRio and INT since 1995, to establish a national hardness metrological system in Brazil to Brinell, Vickers and Rockwell hardness scales, is presented, e.g. the development of reference blocks, for different ranges of Rockwell B and C hardness scales. These results and the installation of a hardness standardization machine and an indenter calibration system at INMETRO will fill the existing voids up in the Brazilian traceability chain in hardness metrology.
XVIII IMEKO World Congress
· TC5
· 2006
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Takashi Yamamoto
Looking at the current status of hardness standards, we occasionally come across the view that it is sufficient that hardness measurements can be matched somewhat forcibly to the hardness values of standard blocks. However, if the direct accuracy of a hardness tester and indenter and loading conditions are well managed and appropriate testing procedures are taken, the measurement of hardness should naturally agree with the value indicated on a standard block, and “hardness” should be an industrial quantity obtained in that way. Therefore, we should recognize anew the original purpose of a...
XVIII IMEKO World Congress
· TC5
· 2006
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Satoshi Takagi, Kazuyuki Kamijo, Takashi Usuda, Haruo Kawachi, Kazutomi Hanaki
The three different methods, the NRLM-type Vickers indenter verification instrument, the scanning white light interferometry and the atomic force microscope, are used for the wide-range verification of a Vickers indenter. Those methods are available in different range of indenter surface and it was found that the integration of different instruments are helpful for the better understanding of the thorough geometry of a Vickers indenter. In addition, an improved instrument is developed for low-force and microhardness range and evaluated its availability. The results show that it can indicate...
XVIII IMEKO World Congress
· TC5
· 2006
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John Song, Samuel Low, Alan Zheng
Standard Rockwell diamond indenters play an important role for a worldwide unified Rockwell hardness scale. In 1994, the National Institute of Standards and Technology (NIST) established a Microform Calibration System with sufficiently small calibration uncertainty for the calibration of standard Rockwell indenters. In 1995, NIST established a group of Rockwell diamond indenters characterized both by high geometrical uniformity and hardness performance uniformity. One of them, No. 3581, was selected as the NIST’s primary Rockwell diamond indenter for the calibration of NIST’s Standard...
XVIII IMEKO World Congress
· TC5
· 2006
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Sergio Desogus, Alessandro Germak, Claudio Origlia, Giulio Barbato
Much work has been done on Rockwell diamond indenters to evaluate the relationship between geometry and hardness measurement results. However, it has been observed that the residual after geometrical correction is significant (within ±0,3 HRC). Some investigations on the non-geometric parameters of the Rockwell diamond indenters, as mechanical properties of the diamonds and the soldering of the diamond prism into the holder, were carried out in the past. Recently, using the INRiM primary machine, some experimental tests were carried out to investigate the possibility to correlate the...
XVIII IMEKO World Congress
· TC5
· 2006
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Zdenek Havranek
The paper describes theoretical design and simulation results of the high precision amplifier for use in metrology especially for measurement of low AC voltage in a wide frequency range. The whole device will be used in process of calibration of common multimeters with AC/DC comparation technique.
XVIII IMEKO World Congress
· TC4
· 2006
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Paul Roberts
Calibrating a Spectrum Analyzer usually involves a variety of measurements, with each requiring a suitable input signal. A typical procedure generally utilizes a number of signal generators together with other pieces of equipment to generate the signals and ensure their accuracy. This paper provides an overview of spectrum analyzer calibration with discussion of the most common calibration tests, their signal requirements, and approaches for meeting those requirements.
XVIII IMEKO World Congress
· TC4
· 2006
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L. S. Palma, A. Oliveira, R. C. S. Freire, A. B. Fontes
This work presents the system performance analysis, in terms of frequency response and system resolution, of a 1-bit first-order Σ-&Delta thermal modulator. In this system model, some of the operations conversion is performed by the thermoresistive sensor, which operates at constant temperature method. The system performance analysis was realized with a sampled version of the continuous time thermal Σ-&Delta modulator. It will be shown that system performance is dependent on the system oversampling ratio (OSR) and the system transfer function pole and zero which depends on thermal and...
XVIII IMEKO World Congress
· TC4
· 2006
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Mariana-Rodica Milici, Leon Mandici, Laurentiu-Dan Milici
The described measurement system is recommended for the measurement of the water level in hydroenergetical accumulations because permits the measurement of the water level in large limits with the error e desirable by user, eliminates the possible measurement errors due to the zones which could appear in the cold season between the water level and the appeared ice bridges and due to the fact that are used two distanced contacts systems are eliminated the situations appeared when the sensors register erroneously by reason of some objects appeared in the sensors placed above the water level.
XVIII IMEKO World Congress
· TC4
· 2006
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M. Caciotta, F. Leccese, A. Trifirò
The Perceived Power Quality by costumers has been faced, starting from ISO 9000 Quality definition. An experimental investigation is presented on customers of Rome (Italy). By the results one demonstrates that fluxes of parameters defined on own manner by costumers, can be determined.
XVIII IMEKO World Congress
· TC4
· 2006
· Download