P. Arpaia, C. Petrone, S. Russenschuck
Errors in the transversal field of accelerator magnets are usually expressed in terms of the coefficients of a harmonic expansion on a circular trajectory in the magnet’s aperture. An elliptic trajectory more suited to apertures with large width-to-height ratios allows the field inside the domain to be reconstructed with a higher accuracy. Displacing an oscillating wire along an elliptical trajectory and acquiring the amplitude of the wire oscillation at each point yield a periodic signal to be expanded into the elliptic multipoles. The paper discusses the theoretical background, the...
XX IMEKO World Congress
· TC4
· 2012
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Po Gyu Park, Young Gyun Kim, Wan-Seop Kim, Mun-Seog Kim, V. Ya. Shifrin
We have carried out precision magnetic measurements utilizing a magnetic-resonance technique, aiming for improving the magnetic-field standard below 100 mT. The standard for measuring dc magnetic flux density is intended to cover the range from 10 mT to 100 mT, with an uncertainty ( k = 2) ranging from 4 mT/T to 10 mT/T.
XX IMEKO World Congress
· TC4
· 2012
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P. Arpaia, L. Fiscarelli, L. Walckiers
Synchrotron particle accelerators are mainly composed of magnets. Long dipole magnets are employed to bend and to contain the beam within a circular trajectory. Their field quality is usually tested by arrays of rotating coils. Typically the measurements must be affected by low uncertainty (±10 -4 ) and the calibration of the sensing coils, in terms of surface and angle, is critical. In this paper, a new method for the coil calibration is presented. The method is firstly stated formally and then validated in an actual use case. Experimental results demonstrate the capability of the method to...
XX IMEKO World Congress
· TC4
· 2012
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P. Arpaia, C. Petrone, L. Walckiers
A method to measure the magnetic axis position of a solenoid magnet by means of a vibrating wire is proposed. The method allows the magnetic axis to be found in spite of the low transversal field. The experimental results of the magnetic axis measurements on a prototype solenoid magnet of the linear accelerator for the low energy beam transport line at CERN are illustrated.
XX IMEKO World Congress
· TC4
· 2012
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Ján Šaliga, Linus Michaeli, Ján Buša, Jozef Lipták, István Kollár, Tamás Virosztek
ADC test methods require the best possible reconstruction of the input signal to the ADC under test from the acquired, therefore erroneous ADC output data. The commonly used LS fit and the recently introduced maximum likelihood estimation are competing methods. This paper presents an experimental comparative study of these estimation methods with the goal to investigate the behaviour of both methods and to determine their limits. An alternative algorithm for the calculation of the maximum likelihood fit is also examined. Some practical recommendations for the choice of optimal method for...
XX IMEKO World Congress
· TC4
· 2012
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K. Fukuda, K. Yoshida, T. Kinugasa, S. Fujimoto, K. Kanazawa
Real time design methods of FIR filters for weigh-in- motion have been proposed in order to improve the accuracy of measured axle weights. However, if the order of the filter is inappropriately set, the method fails to estimate the frequency of the vibratory component. The application of a reduced-tap sparse FIR filter, which has only one non-zero coefficient to be determined, has recently been studied for preventing miscalculation of axle weights. The latest results show that the adoption of the filter is very effective for estimating virtual vibration and static axle weights of weighing...
XX IMEKO World Congress
· TC3
· 2012
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Dan Mihai Stefanescu, Alexandru-Titus Farcasiu, Adrian Toader
The TensoDentar is a complex measurement system of dislodging forces for complete dentures or palatal plates. An original strain gauge force transducer (SGFT) and virtual instrumentation in NI and LabVIEW environment are used conforming to a rigorous clinical protocol to evaluate the efficiency of two surface treatments (sandblasting and plasma treatment) on complete denture base materials. The present work has the unprecedented goal to achieve in vivo comparison of the two techniques. First experimental results obtained are presented and interpreted.
XX IMEKO World Congress
· TC3
· 2012
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Zoltan Zelenka
The Austrian Federal Office of Metrology and Surveying (BEV) has developed and realized in cooperation with Sartorius AG (Göttingen) and the Vienna University of Technology, three handling systems for automatic calibration of weights on high-precision mass comparators. The metrological performance of these systems has been studied. Recent developments in BEV, like the new laboratories, improved techniques for the dissemination of mass unit required an update and further development of the previous study.
XX IMEKO World Congress
· TC3
· 2012
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Meng Feng, Zhang Yue, Zhang Zhimin, Li Tao
The paper describes a new multifunction torque standard machine at NIM. National institute of Metrology has established a multifunction torque standard machine. It has three main functions. One is hydraulic torque wrench calibration. The second function is torque multiply calibration. The third function is reference torque standard machine. This paper introduces the structure and the working principle of the equipment, performance parameters and the uncertainty evaluation.
XX IMEKO World Congress
· TC3
· 2012
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Goutam Mandal, Anil Kumar, Dinesh Chandra Sharma, Harish Kumar
The National Physical Laboratory, India (NPLI) is the custodian of National Prototype of the Kilogram (NPK) No. 57, which was provided by the BIPM in 1958 after its first calibration in 1955. The NPK has been recalibrated in 1985, 1992 & 2002 so far at the BIPM. The change in mass values are estimated 218 µg from 1955 to 1985 (7.3 µg/year), 36 µg from 1985 to 1992 (5.1 µg/year) and 24 µg from 1992 to 2002 (2.4 µg/year) between after cleaning and washing of previous calibration to before cleaning and washing of next calibration. Now, the recalibration period of NPK is maximum 10 years. The...
XX IMEKO World Congress
· TC3
· 2012
· Download