O. Mack
This contribution describes new methods to characterize and determine both, the drift and the non-linearity of piezoelectric force measuring devices. The influence of the drift and dif-ferent procedures for the drift calculation are presented. In addition the influence of different load regimes and evaluation procedures is discussed. The measurements carried out reveal that not the drift, but in particular the non-linearity is the criterion crucial for a classification of piezoelectric force transducers according to standards commonly applied to strain gauge force transducers. The results of...
TC3 Conference 2001
· TC3
· 2001
· Download
D. M. Stefanescu, A. Stefanescu
A thoroughgoing study idea of the sensitivity increasing methods for strain gauged force transducers sprang up many years ago in Romania. It's a theme that requires the knowledge of different fields: Applied Metrology, Deforming Solid Mechanics, Strength of Materials and Elasticity, Experimental Stress Analysis, Force & Torque Measurements, Electronic Instrumentation, Numerical Methods, Structural Optimization. The measurement and analysis of the forces and moments require special transducers with utmost precision and remaining robust in severe experimental conditions. Their design is based...
TC3 Conference 2001
· TC3
· 2001
· Download
D. M. Stefanescu, F. Stefanescu, L. Luca, T. Manescu
The living creatures provide a lot of gripping biomechanisms. The study of these biomechanisms makes possible the discovery of interesting equivalent mechanisms, which can be used for industrial robots in many fields of activity. It is possible to obtain some technical gripping mechanisms starting from the ones of the living creatures in their biological evolution: insects (stag beetle), birds (parrot), marine (crawfish) or terrestrial (elephant) animals, human beings. It is a good idea to try the synthesizing of a universal gripping mechanism.
TC3 Conference 2001
· TC3
· 2001
· Download
G. Navrozidis, F. Strehle, D. Schwind, H. Gassmann
The following paper gives a detailed overview of the characteristics of the new state-of-the-art force standard machine commissioned in July/August 2000 at site of the Hellenic Institute of Metrology by the manufacturing company GTM. The fully automated force standard facility is a combined dead weight - lever amplification machine with 110 kN direct load capacity and a 10:1 lever multiplication part and is to be the National Force Standard of Greece. The 110 kN dead weight section is equipped with a mass stack of nickel-plated steel weights realising discrete forces in compression and...
TC3 Conference 2001
· TC3
· 2001
· Download
T. Allgeier, H. El-Hakeem, A. El-Sayed, B. Glöckner
A new dead weight force standard machine covering the range from 10 kN to 1 MN has been designed and constructed at the National Institute for Standards (NIS)-Egypt, by GTM GmbH. This machine incorporates an electromechanical system that allows the generation of any load from 10 kN to 500 kN in steps of 5 kN with only 10 masses by selecting a suitable combination of these, while keeping the load on the transducer under calibration constant. Furthermore, it allows the generation of additional loads of up to 500 kN, so that 1 MN is reached by full deadweight action and full substitute load at...
TC3 Conference 2001
· TC3
· 2001
· Download
M. I. Mohamed, H. M. Abdel-Hakeem, A. A. El-Sayed
The universal calibrating machines are used extensively in industrial, governmental, and military laboratories for the calibration of various force transducers (load cells, dynamometers, proving rings, and other force measurement devices). There are many important factors that might affect the measurement process. These factors may be summarized as: the possibility of existing friction between moving and stationary parts, the rotational effect of the reference standard load cell, the repeatability of measurements, the effect of the number of runs, the eccentricity effect, hysteresis and...
TC3 Conference 2001
· TC3
· 2001
· Download
R. Kumme, O. Mack, B. Bill, H. R. Haab, C. Gossweiler
This contribution describes different measurement facilities and procedures for the calibration of piezoelectric force measuring devices. In National Metrology Institutes forces are generated in force standard machines in force steps. In force calibration machines of industrial calibration laboratories forces can be applied in steps or continuously. The traceability is realised with force transfer standards, which are calibrated in force standard machines. A comparison of these different calibration procedures is discussed in this contribution.
TC3 Conference 2001
· TC3
· 2001
· Download
T. Bruns, M. Kobusch
In addition to the dynamic force calibration with harmonic excitation, a new method for impulse forces is under development at PTB in Braunschweig. The forces of up to 20 kN are generated by the impact of two masses guided by air bearings. Traceability for force is realized via the measurement of acceleration with laser-Doppler-interferometers and the determination of the moving masses.
TC3 Conference 2001
· TC3
· 2001
· Download
Y. Fujii
In this paper, present status of the developing impulse generator based on the law of conservation of momentum is reviewed. Impulse responses of two commercial force transducers are evaluated by means of this method. In the experiment, an object levitated with sufficiently small friction using a pneumatic linear bearing is collided with a force transducer. The inertial force acting on the object is measured as the product of the mass and the acceleration. Approximately 160 sets of collision experiments, whose impulses with the maximum value of approximately 20 to 230 N with the half value...
TC3 Conference 2001
· TC3
· 2001
· Download
A.Marinescu, R. Tircomnicu, E. Marinescu
In the paper it is presented a possibility to reduce power demand of a magneto elastic laminated core transducer based on the using of a combination of electromagnetical active and passive sheets. Due to the different stiffness of the two types of sheets it is used the finite element method for the strain and stress field analysis in the sheet stack in three cases: sheets in contact without / with friction and adhesive stacked sheets. The results of this simulation are compared with the experimental results on the basis of some performance analysis criteria.
TC3 Conference 2001
· TC3
· 2001
· Download