One of the main tasks of the National Metrology Institutes (NMIs), besides the realization and improvement of standards for the different physical and other quantities, is to carry out comparisons between their own standards and those of other NMIs. At the highest level, the CIPM key comparisons involve at least the standards with the smallest uncertainties of measurement in the world and should cover - if possible - all geographical regions through the corresponding Regional Metrological Organizations (RMOs). It is also intended to compare different realization techniques of the given...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
The highest level of torque calibration is achieved by direct loading and, due to the use of mass stacks, is associated with the step-by-step method. In order to fit the demand of applications especially in industry, calibration devices with the ability of performing continuous loading were developed which are working as reference machines. A benefit of continuous methods is that the time for a loading-unloading cycle can be ten times or more shorter than using the step method. This fast change in torque leads to conditions of use that cannot be represented in the national torque standards....
Force, Mass and Torque Measurements · TC3 · 2005 · Download
This article deals with the vertical 20 kN·m torque reference calibration device newly built by MIKES- RAUTE. It widens the possibilities of the MIKES-RAUTE Mass and Force Laboratory in the field of torque calibrations from 2 kN·m up to 20 kN·m. A brief overview about the construction and setup of the device is included in this report. Also some information about the applied calibration process is given. The main part of this article describes comparison measurements with the PTB, Germany, from summer 2004 and presents their results. They show that the device will attain an uncertainty level...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
Measuring of large forces up to 10 MN with high accuracy is a complex subject, blending theory, practice and applications, with a special accent in the field of Metrology. It is simply to generate complex shapes of mono-block elastic structures starting from simple shapes of strain gage measuring sections, the axisymmetrical ones being the best suited in this respect. The body of the force transducer is easy to design by 2D axisymmetric FEM and easy to manufacture. The paper have in view a unified approach of square (type A) and rectangle (type B). Square section is among the few with an...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
Strain gauges are an important tool in measuring techniques applied to determine loads and detect damages. Due to their high signal-resolving power, they are also suitable for stress analysis in building constructions. Without specific encapsulation, they are, however, suitable only for short-term measurements. Therefore, a completely new encapsulation type was developed at PTB. The strain gauges were placed in a sensor housing which protects the sensitive technology - similar to common force transducers - and is fitted into a small measurement borehole of the structure. These applied...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
A revised draft of OIML R111 has been approved recently. Among the many notable changes to the previous edition are specific requirements for both the magnetic susceptibility and residual magnetization of weights used in legal metrology. The highest class of such weights is E1, for which a 1 kg weight has a manufacturing tolerance of ± 0.5 mg. It therefore follows that better magnetic properties might be needed for weights having mass uncertainties substantially better than E1 tolerances. The work presented below shows how this problem was approached at the BIPM and supports our conclusion...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
In conjunction with low-drift charge amplifiers static force and weighing measurements get more and more important for piezoelectric force transducers if the measuring time and time of load change are in the range of a few minutes. The presented investigations according to the international recommendation OIML R60 [7] point out, that piezoelectric sensors can be used for static applications with low accuracy requirements (e.g. class D for ordinary accuracy weighing instruments). With suitable methods for compensation or adjustment the sensors even meet the higher requirements of medium...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
J. W. Chung, M. Borys, M. Firlus, W. G. Lee, R. Schwartz
Buoyancy artefacts (BAs) are used for the experimental determination of air density. The artefacts used for this comparison were manufactured at the PTB and the KRISS respectively and consist of one hollow cylinder and one bobbin. Mass differences of the PTB and the KRISS BAs in vacuum and in air are measured simultaneously by using the PTB prototype mass comparator. Results of the bilateral comparison including uncertainty budgets and the deviation between air densities obtained by the BAs and those calculated by the CIPM formula are presented. Additionally, a comparison with a correction...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
In this paper, we investigate the characteristics of commercial AFM cantilevers and force calibration cantilevers in the range of 10 nN ~ 1000 µN by use of a high precision balance with resolution of 1 nN and 1-D fine positioning stage. This document is a guideline to the authors of papers to be presented at the TC3 2005 conference. These directions are written in the format required for papers. We advise you to download these directions as a MS Word document and use it as the template for your paper because it contains all necessary formats and styles. Papers should be submitted before...
Force, Mass and Torque Measurements · TC3 · 2005 · Download
In this contribution new experiences with a force measuring facility [1] for the range from 1 mN to 5 N consisting of a piezoelectric positioning unit for force generation and a precision compensation balance for force measuring are presented. The enhancement of the facility by means of a rotational table allows to rotate the force transducer under test around its axis and to measure the sensitivity of the transducer at different positions. By averaging the measured sensitivities of a complete rotation cycle the rotation effect can be taken into account and the deviation from the calibration...
Force, Mass and Torque Measurements · TC3 · 2005 · Download