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Dan Mihai Stefanescu
Strain gauged elastic elements for force and related quantities measurement

Force, Mass, Pressure, Acceleration, Vibration and other mechanical quantities are strongly connected by their physical formulas, by their like measurement principles and – last but not least – by the complex scientific program of the jointly 20th TC3, 3rd TCl6 & 1st TC22 IMEKO Conference, held in Merida, Mexico, in November 2007. Force as an important mechanical quantity has a privileged position inside the Asian "planetary system" of units or atop the "Newton apple tree" suggesting SI units system. Force can be measured with a lot of elastic elements using various measurement principles. Among them those based on strain gauges as resistive transducers are predominant. Three complex and spectacular applications concerning Force and associated quantities measurement are shown in three different environments: solid, liquid and air.

Marinel Temneanu, Romeo Ciobanu, Codrin Donciu
Amorphous wire based stress sensor working with low carrier frequency

Impedance spectroscopy methodology is used in this article to evaluate the influence of axial applied stress on complex impedance components of as cast CoFeBSi wires in the 100 Hz to 300 kHz frequency range, at 10 mA ac current. Based on the obtained results, problems of practical significance are discussed since the envisaged application is the construction of sensitive stress sensors for detection of such as pressure, tension and stream speed for liquid and gases.

Mladen Franz, Željko Alar, Tamara Aleksandrov
Implementation of the reference force standard in the Croatian Metrology and Interlaboratory Comparison

Laboratory for Testing Mechanical properties (LIMS) at the Faculty of Mechanical Engineering and Naval Architecture in Zagreb is accredited laboratory for force and a holder of National standard for force in the Republic of Croatia. Reference force standard with measuring range 10 - 500 kN was installed in LIMS at the end of 2005 with the intent of continuous improvement of the metrology infrastructure of Croatia. The load is obtained hydraulically and the measuring system consists of double placed reference transducers with the nominal force 100 kN and 500 kN. Preliminary investigations have shown that the relative measurement uncertainty will be less than 5 x 10-04. Further investigations are current.
LIMS has planned to participate in the interlaboratory comparison between two more laboratories. Intercomparison will be done in measuring range 10 – 500 kN using two commercial force transducers of 100 kN and 500 kN nominal values. The best measurements capability (CMC) of the participating laboratories varies from 0,002% to 0,05%. The calibration of the force transducers will be carried out using the laboratories own calibration procedure, the relevant classification data, i.e. rotation effect, repeatability, hysteresis as described in DIN EN ISO 376. Intercomparison will increase the level of Croatian metrology thus providing further cooperative investigations in association with European and Global National laboratories for force.

David Kimetto
The use of strain gauges in the Kenyan industry for measurement

The rapid development of micro-electronics has produced an increasing demand for small sensors offering high quality performance. Strain gauges are an important aid in all areas of experimental stress analysis, for determining the strain on the surface of components. In addition, the uses of strain gauges in the manufacture of transducers for measuring mechanical quantities has proven to be extremely reliable technology, giving excellent results.

J.A. Robles Carbonell, J.A. Fernández García,Jorge L. Robles Verdecia
Enlargement of the force capability at CEM: development of a 10 MN hydraulic force standard machine

This paper describes the constructive characteristics of 10 MN tension– compression hydraulic force standard machine installed at CEM during the period 2006-2007 and its traceability to national standard.

González Espinosa David, Pérez Ramírez Edgar
Load cells temperature effect in force applications for automotive industry requirements

In Technical Development Department of Volkswagen de México (VWM) have been make test to some parts of the cars like body, chassis, interiors, safety and electric. Examples of these tests are the life time of covering of the doors, servo-brake, brake pedal, and others. For these tests generally the standard requirement are -35 °C, ambient temperature (23 °C ± 5 °C) and 80 °C with force applying on the functional parts e. g. 8 000 cycles applying 100 N at every temperature on interior covering of the door; but what happened with the load cell at these different temperature that ambient. This article describes two different responses of the two load cell @ -35 °C and +80 °C.

M. Ueki, T. Kobata, K. Ueda and A. Ooiwa
Automated volume measurement for weihts using acoustic volumeter

An automated method using an acoustic volumeter to measure the volume of weights mass ranging from 1 g to 100 g is described. The automated system consists of a manipulator of three-axis motion, a container lifting mechanism, a stationary weight magazine with 30 weights positions, a control unit, a personal computer and an acoustic volumeter. The acoustic volumeter with the weight exchanging system enables to perform fully-automated volume measurements. The reliability of the automated acoustic volumeter is experimentally examined, and the measurement uncertainty of the volume of the small mass weights is evaluated. Combined standard uncertainty is estimated to be 0.0021 cm³ in case of volume measurement of a 100 g weight, whose nominal volume is 12.5 cm³. It is confirmed that the automated acoustic volumeter can be applied to volume measurements of small weights with sufficient accuracy for the OIML class E1.

Gasper Vindisar, Matej Grum, Martin Terlep
Evaluation of standard uncertainty of measured mass difference on 10 kg comparator balance

Three pairs of different weight support plates, which are needed in the procedure of multiplication of 1 kg value, were used on Sartorius C10000S comparator balance in order to study their influence to the measurement results. In the study a pair of 2 kg weights was compared with the aid of different support plates. The mean values and the standard deviations of the measurements with the support plates were compared to the results of measurements without the use of the support plates. The analysis confirmed the differences in the means and in the standard deviations of measured results when various support plates were used but in a smaller extent as it had been noted in earlier routine measurements. The analysis showed that the use of a certain pair of the plates assured smaller standard deviations and better agreement with the results of measurements where the plates were not used.

T. Fröhlich, T. Fehling, B. Gatzemeier, S. Osang, D. Heydenbluth
Mass dissemination using a fully automated mass comparator robot system

We used a new mass comparator robot system which covers 6 decades from 1kg down to 1mg in a single system to calibrate an entire 1kg-1mg OIML (5, 2, 2*, 1) weight set against one 1kg reference by subdivision in less than 1.5 days using a fully automatic robot system with no operator action except loading the magazine at begin.
Due to the possibility to perform subdivision comparisons of one weight against combinations of up to four other weights we don’t need the "5" check standards. We use one additional "1" check standard and 8 equations for the 5 unknown in each decade. The mean values of the weighing differences of 6 ABBA cycles are used for the adjustment calculation. A detailed description of the weighing design and the adjustment calculation is given.

Christian Buchner
Fully automatic mass laboratory from 1 mg up to 50 kg – Robots perform high precision mass determination

In order to meet the requirements for a state-of-the-art metrology institute and in an endeavour to build a fully automatic mass laboratory, the Austrian Federal Office of Metrology and Surveying (BEV) has developed and realized in cooperation with Sartorius AG in Goettingen and the Vienna University of Technology three different handling systems for automatic testing weights on high-precision mass comparators.
Fully automatic System for alternating weights on mass comparators with different weighing capacity have been realized; one from 1 mg up to 10 g, one from 10 g up to 1 kg an the third one from 1 kg up to 20 (50) kg using two comparators. The resulting load alternator "robot" holds between ten and eighty test weights and a corresponding number of reference Standard weights. All weights are transported without pallets. The Systems are based on Computer control and linear drive trains, and are used at the BEV to disseminate mass and for the calibration and verification of weights.

Page 830 of 938 Results 8291 - 8300 of 9371