Renato Reis Machado, Cláudio Afonso Koch, Rafael Soares de Oliveira, Ana Rosa Martins, Carlos Rodrigo Roesler, Ieda Caminha
Orthopaedic implants should be designed and manufactured in such a way to protect the patient and user against imperfections and damages. These medical devices require specific tests to evaluate their performance like: tensile strength, resistance to wear and fatigue, among others. These tests represent a way to ensure that the implants are both reasonably safe and effective for their intended use. Due to design requirements dictated by the anatomy, and physiology of the skeletal structure of the human body, these devices present complex geometric forms and so fatigue tests often involve...
XIX IMEKO World Congress
· TC3
· 2009
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Luca Callegaro, Vincenzo D'Elia, Bruno Trinchera
National Metrology Institutes employ the quadrature bridge in the traceability chain to derive the farad from the ohm (represented with the quantum Hall effect). The bridge calibrates the capacitance product of the two capacitors being measured; a separate measurement with a ratio bridge is usually required to estimate each capacitor independently. We describe here a method which, by measuring three capacitance standards with the quadrature bridge only, permits to derive the value of each capacitor without resorting to other measurement systems. The method has been checked with an automated...
XIX IMEKO World Congress
· TC4
· 2009
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Albert Weckenmann, Teresa Werner
Measurement results provide important information about the measured objects. In industrial application, this is used to inspect products and control processes. To enable reliable statements based on the measurement results, all concerned employees need sufficient competences to fulfil their specific tasks, e.g. a correct execution of the measurement task, but also a proper interpretation of measurement results or inspection-oriented and functional dimensioning. So far, many training offers for operators in metrology have been developed. But other user groups in an industrial enterprise also...
XIX IMEKO World Congress
· TC1
· 2009
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Gustavo Ripper, Ronaldo Dias
This paper discusses the effect of residual components on type A uncertainties determined by multiple linear regression of quadrature homodyne output signals. Primary accelerometer calibrations employing the sine-approximation method allow the determination of the fit uncertainty through the covariance matrix. Frequency components that are not included in the regression model lead to increased uncertainties. The uncertainty obtained from the regression is therefore not exclusively due to random data variance at the calibration frequency, but due to deterministic error of the model. Analysis...
XIX IMEKO World Congress
· TC22
· 2009
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Koichiro Hattori, Yutaka Seino, Takashi Usuda
In the instrumented indentation test including nanoindentation, the mechanical parameters are calculated by test force and indenter contact/surface area. The area is determined as a function of depth, which is measured as the displacement from surface of sample. Therefore how to determine the surface is important, however, it is not easy to determine sample surface exactly during the test. Because nanoindentation machines detect the surface as a velocity decreasing point or stiffness increasing point with monitoring the indenter motion at the surface finding process. The detected surface...
XIX IMEKO World Congress
· TC5
· 2009
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Norbert Greif, Graeme Parkin
Software is an intrinsic part of measurement. It is used in instruments to control experiments, store and process measurement data, analyse and display results and to implement mathematical techniques. Some innovations in measurement have been enabled through the use of software for simulations or complex analysis. For example, the international temperature scale ITS90 requires the processing of high order polynomials and can only be implemented using software. Given this reliance, improvements in the quality of software and reduced cost of its development are vital to the effective delivery...
XIX IMEKO World Congress
· TC21
· 2009
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Roberto Buccianti, Marco Cibien, Luca Mari, Bruno Rebaglia
The paper analyzes the concept of accuracy, and the related ones of trueness and precision, as aimed at characterizing the behavior of measurement processes, and highlights how such concepts, as currently defined by some relevant standards, should be reformulated to guarantee their consistency. Finally, some preliminary suggestions are proposed to this goal.
XIX IMEKO World Congress
· TC7
· 2009
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Jorge C. Torres-Guzmán, Salustiano Ruiz, Pablo Olvera, Mª. Nieves Medina
The results of a comparison in differential pressure between CEM-Spain and CENAM-Mexico are presented here. The comparison was performed in 2008. A high accuracy digital manometer was used for the comparison. The manometer had good behaviour during the period of the comparison, having a small drift which had no effect in the comparison. The results of the measurements showed very good agreement between the measurements performed by CEM and CENAM. For the range of the comparison it can be said that CEM and CENAM have equivalence of measurements.
XIX IMEKO World Congress
· TC16
· 2009
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Elsa Batista, Nelson Almeida, Eduarda Filipe, Peter Lau
The EURAMET Key comparison "Volume comparison at 20 L", between fourteen National Metrology Institutes (NMIs), was performed with a gravimetric method procedure. This paper describes the data evaluation (determination of the reference value and a chi-square test) and uncertainty analysis of the results.
XIX IMEKO World Congress
· TC9
· 2009
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Li Tao, Dai Ming, Lin Jing, Zhang Yue, Zhang Zhimin
This paper describes the development of torque standard machines in China, its measurement range and its measurement uncertainty information etc. Also, the situation of torque standard machines which are in building process or will be built in the future is described in this document. In 1970's, the first standard machine for measuring torques was developed in Shanghai and it initiated the history of torque measurement in China. In the whole development process, there appeared four types of machines, which are: a) the rolling bearing type, b) the knife-edge type, c) the air-bearing type and...
XIX IMEKO World Congress
· TC3
· 2009
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