Proceedings

EVALUATION OF PRESSURE DISTORTION COEFFICIENT FOR 200 MPa PISTON CYLINDER ASSEMBLY

Recently a special attention has been given to the design and metrological characteristics of pressure balance, in particular to the evaluation of pressure distortion coefficient of piston cylinder assembly effective area. In high pressure range namely above 50 MPa, a change of the effective area of piston cylinder units due to elastic distortions becomes one of the main sources of uncertainty of the measured pressure. The elastic distortion coefficient for piston cylinder unit of range 200 MPa used at National Institute of Standards (NIS) was measured through cross-floating experiment and...

ESTABLISHMENT THE TRACEABILITY OF NIS PISTON-CYLINDERS FOR THE 200 MPa RANGE OF HYDRAULIC PRESSURE

Pressure balances are excellent standards for measuring pressure with acceptable uncertainty and they are widely used at the primary pressure laboratories in the world. This study aims to establish the traceability of NIS piston cylinder assemblies for the 200 MPa hydraulic pressure range by calibrating them with the smallest uncertainty. All assemblies will be traceable to a transfer standard calibrated at BNM-LNE- France using di-ethylhexyl-sebacate as the pressure medium. The consistency of all calibration data available will be investigated in order to draw conclusions regarding the...

CHARACTERIZATION OF A PROTOTYPE PISTON-CYLINDER UNIT DESIGNED AND MANUFACTURED WORKING IN THE PRESSURE RANGE 0.5-35 MPA HYDRAULIC MODE

The prototype piston-cylinder unit covering a pressure range of 0.5-35 MPa in the hydraulic mode and its assembly was designed and manufactured. The elastic distortion coefficient, lambda (?) of the piston- cylinder unit of a prototype pressure balance, used in primary standard gauges, was experimentally and analytically determined using cross-floating method and a Finite Element Analysis (FEA) software respectively. Since it is a well-known phenomenon that the elastic distortions in the piston and cylinder materials contribute as a source of high uncertainty among the total uncertainty...

The unit kilogram, needs and experiments for a new definition

NEW WAYS TO DETERMINE VERY SMALL MASSES AND FORCES

The goal of this paper is to draw attention to mass determinations at nominal values well below 1 µg. Traceability to the International System of Units (SI) is challenging because mass standards having nominal values less than 1 mg are difficult to produce and thus not commonly available. We limit this burgeoning subject to only three examples: the calibration of atomic force microscopes with respect to calibrated dead-weights; the confirmation that a NEMS device has attogram resolution; and the direct determination of the gravitational mass of the neutron. We do not mention the important...

THE NEW 1.1 MN·m TORQUE STANDARD MACHINE OF THE PTB BRAUNSCHWEIG/GERMANY

Until 2003 it was impossible to perform traceable calibrations for torque measuring systems above applied torque values of 200 kN·m anywhere in the world. Up to this figure such calibrations are possible at LNE/Paris. This is despite the fact that a number of applications with considerably larger torque values are known (energy generation, shipbuilding etc.). In addition there are requests for calibrations above the largest measuring range so far available at the PTB (20 kN·m), as realised with a deadweight torque standard machine (20 kN·m TSM) acting on a double-sided lever arm supported in...

TC 3 – FROM THE BIRTH TO WORLDWIDE RECOGNITION

IMEKO TC 3 after 37 years of its founding organises the 19th Conference in Cairo, 2005. The paper gives a survey of the first 16 years, reporting the first 10 Conferences and round table discussions. The most important personalities are mentioned with the development of the field as well. This heroic period was a firm base of the next 20 years and of the future activities.

NON-GOVERNMENTAL COOPERATION IN MEASUREMENT

IMEKO is a non-governmental federation of 35 national Member Organisations, individually concerned with the advancement of measurement technology and instrument engineering. The Member Organisations are scientific/technical societies or committees. The membership consists of the representatives of metrological institutions, higher education, industry and the users of instruments. The paper deals with the objectives of the Confederation, informs on the structure and financial background, on IMEKO imeko_proceedings and on the activities of 20 Technical Committees. Finally the future World...

Role of the national institute of standards (NIS) in the development of nation

The effective vibration speed of web offset press

The purpose of this study was to investigate the existing maintenance models of web offset presses, and to propose the method which increases the reliability of the printing press exploitation, but does not require big investments. Doctor motors allowed constant monitoring by measuring instruments, which allowed insight in current status of motors at any time, so they could be repaired or replaced before malfunction. The effective vibration speed ( v RMS ) was measured a few times during the year 2006. Standard ISO 2372-1974 (E) defines values and boundaries of the effective vibration speed...