SI quantities and units are the subject to various IMEKO technical committees, not assigned to a certain TC (e.g. time). On the horizon of the adoption of a new SI, the connection between quantities and units remains the same, and their complexity is noticeable in the three graphical representations given (tree, planetary and subway map), reflecting the significance of the Chinese proverb that a suggestive picture values more than a thousand of words.
Diverse fields of Metrology reveal manifold perceptions concerning the meaning of the classical procedure «measurement» and of the trendy procedure «observation». No common consensus has become visible so far. The following systematic investigations of metrological tasks and structures develop and propose a self-evident definition of both procedures and the resulting analytical relationship. This is feasible by modelling and visualising dynamic subsystems by means of Signal and System Theory. In particular, one can consistently demonstrate and justify the complementary tasks of measurement...
The 25 th General Conference on Weights and Measures (CGPM) adopted its Resolution 1 "On the future revision of the SI". According to this Resolution, new definitions for the kilogram, the ampere, the kelvin and the mole will be based on fixed numerical values of selected constants. The Consultative Committee for Mass and Related Quantities (CCM) and the Consultative Committee for Units (CCU) established a joint roadmap in order to ensure that all necessary steps are completed in time for the 26th CGPM in 2018. The paper present these steps and reviews the situation with the criteria...
Uncertainties in results caused by human factors of test persons are well known in the area of testing the speech quality of telephone connections. The presence of this kind of uncertainty components were already known when this test methodology was introduced. For elimination or reduction a new approach by using emotion detection is presented. First results and limits are given. In order to get a universal method standardization is urgently needed.
The Physikalisch-Technische Bundesanstalt (PTB) is currently elaborating a concept for the maintenance and dissemination of the SI unit kilogram on the basis of silicon spheres. For this purpose, handling procedures and work instructions are elaborated. These contain, for example, the cleaning procedures of the spheres, the safe transport and storage as well as procedures for the monitoring of the growth of oxide on the sphere surface. Realisation of the redefined kilogram by means of 28 Si spheres and nat Si qp spheres as primary respectively "quasi primary" mass measurement standards and...
The General Conference on Weights and Measures agreed in principle at its 24 th meeting in October 2011 on new definitions for four of the seven base units of the International System of Units (SI). Kilogram, ampere, kelvin, and mole will be defined in terms of fixed numerical values of the Planck constant, elementary charge, Boltzmann constant, and Avogadro constant, respectively. A refined value of the Boltzmann constant suitable for defining the kelvin is presently determined by fundamentally different primary methods like acoustic gas thermometry, dielectric constant gas thermometry,...
While for measurements on the macro-scale the applied measurement systems and typical influences are generally well understood, this does not hold true for measurements on the micro-scale. This limited knowledge results in a rather high value of measurement uncertainty. Thus, to support a suitable analysis of measurement uncertainty and at the same time enable a targeted improvement of the implemented measurement strategy, an empirical method for the determination of measurement uncertainty based on a systematic approach for system analysis is proposed. On the example of inspecting parts...
The reference thin metal film to calibrate for the thermal diffusivity is being developed in NMIJ. Mo thin film with a nominal thickness of 400 nm is candidate for the reference film. To inspect the fabrication process of the reference material, test films were prepared and estimated in terms of scatter of the physical properties. Thermal diffusivity of those films were measured using the pulsed light heating thermoreflectance apparatus originally developed by NMIJ. The measured thermal diffusivity is 3.46 × 10 -5 m² s -1 and the standard deviation is 0.05 × 10 -5 m² s -1 (1.6%) for 8 films...
The peculiarities of 3D objects image formation with clear shadow projection under their illumination by partially coherent and perfectly incoherent light based on the constructive theory of 3D objects formation are investigated. Threshold algorithms for determining the position of 3D object geometric boundary, taking into account its thickness, the light source angular size and the projection system angular aperture are developed. These algorithms are based on the application of true (calculated) threshold or standard one using the corrective component for threshold. The cases of weak and...
This paper introduces the design and calibration of a capacitive position sensor used for measuring the mechanical deflection of a beam with sub-nanometer resolution. It is known that the most accurate and SI traceable method for displacement measurement is the laser interferometry. However, in our application we need to know not only the displacement of the object under measurement but also its distance to a reference origin. To measure the distance with a common two-beam interferometer, in which the measured displacement is proportional to the number of fringes counted, one needs to move...