New techniques and industrial processes emit infrasound or ultrasound (wind turbines, heat pumps, ultrasonic cleaning systems...), while the mechanism of sound perception outside the hearing range is currently not well understood. Manufacturers and operators of these installations need noise emission regulations to be well-founded and not unnecessarily restrictive: it is therefore necessary to define rational and substantiated criteria to prevent the risks associated with these sounds.

Objectives

Understanding human perception of non-audible sounds

Define the metrological structure necessary to apply safety criteria based on sound perception thresholds

Provide traceability to national standards through the development of a universal ear simulator to model human ear impedance for both adults and children

Summary

Find here the detailled description of the project:

http://www.ptb.de/emrp/ears-project.html

Publications et communications

LAVERGNE T., RODRIGUES D., NEIMANNS V., OLSEN E. S. et BARHAM R., “Universal ear simulator: Specifications and artificial ear canal design”, Internoise 2013, Innsbruck, Autriche,  September 15th-18th 2013.

RODRIGUES D., LAVERGNE T., FEDTKE T., OLSEN E. S., BARHAM R. et DUROCHER J.-N., “Methodology of designing an ear simulator”, Internoise 2013, Innsbruck, Autriche, September 15th-18th 2013.

RODRIGUES D., LAVERGNE T., OLSEN E.S., FEDTKE T., BARHAM R. et DUROCHER J.-N., “Methodology of Designing an Occluded Ear Simulator”, Acta Acustica united with Acustica, 101, 5, 2015, 1007-1015, DOI: 10.3813/AAA.918895.

RODRIGUES D., LAVERGNE T., OLSEN E.S., BARHAM R., FEDTKE T. et  DUROCHER J.-N., “Design of a new ear simulator”, Inter-Noise 2015, San Francisco, United States of America, August 9th-12th 2015.

 

Partners

Laboratoires nationaux de métrologie :

  • PTB (coordinateur du projet),
  • NPL,
  • LNE,
  • DFM,
  • Tubitak UME,
  • BKSV-DPLA

The development of practical means to ensure traceability between a new definition of the kilogram and the current mass scale is necessary both to initially fix the value of the Planck constant consistent with the current scale (based on the International Prototype of the Kilogram), and for the dissemination of the mass unit that will be materialized under vacuum from the new definition.

Objectives

Development of artefacts and methods to ensure the traceability of the kilogram from a materialization in vacuum

Summary

Find here the detailled description of the project:

http://www.newkilo.eu/

Publications and communications

PLIMMER M. D., DU COLOMBIER D., IRAQI HOUSSAINI N., SILVESTRI Z., PINOT P. et HANNACHI R., Apparatus to measure adsorption of condensable solvents on technical surfaces by photothermal deflection, Review. Sci. Instrum., 83, 114905 ,2012,  DOI: 10.1063/1.4767245

SILVESTRI Z., AZOUIGUI S., BOUHTIYYA S., MACÉ S., PLIMMER M. D., PINOT P., TAYEB-CHANDOUL F. et HANNACHI R., Thermal desorption mass spectrometer for mass metrology, Review. Sci. Instrum., 85, 045111, 2014, DOI: 10.1063/1.4870921

DAVIDSON S., BERRY J., SILVESTRI Z., HOGSTROM R. et GREEN R., Addressing the requirements for the practical implementation and ongoing maintenance of the redefined kilogram, IMEKO International TC3, TC5 and TC22 Conference, Cape Town, South Africa, 2014.

 

Partners

  • NPL (GB),
  • CMI (CZ),
  • CNAM (FR),
  • DFM (DK),
  • EJPD (CH),
  • LNE (FR), MGRT (SI),
  • MIKES (FI),
  • PTB (DE), 
  • SMU (SK),
  • TUBITAK (TR),
  • INRIM (IT),
  • NRC (CA)

In Europe, the metrological connection needs in force are not covered beyond 15 MN. This corresponds to industrial applications in many fields (mechanics, construction, energy). The needs are estimated up to 50 MN.

Objectives

Extending the range of force measurements above 15 meganewton

Consolidate force measurement uncertainties with force pyramid benches

Improve the calibration control of multi-component sensors

Summary

Find here the detailled description of the project:

http://www.ptb.de/emrp/forcemetrology.html

Publications and communications

RABAULT T., AVERLANT P., and BOINEAU F., “Numerical modeling of hysteresis applied on force transducer”, XXI IMEKO World Congress “Measurement in Research and Industry, Prague, Czech Republic,  30 août - 4 Septembre 2015,

KUMME R., TEGTMEIER F., RÖSKE D., BARTHEL A., GERMAK A. and AVERLANT P., “Force traceability within the meganewton range”, IMEKO 22nd TC3, 15th TC5 and 3rd TC 22 International Conferences, Cape Town, Republic of South Africa, 3 -5 Fevrier 2014

Partners

  • PTB (DE),
  • BAM (DE),
  • CEM (ES),
  • CMI (CZ),
  • INRIM (IT),
  • METAS (CZ),
  • MG (PL),
  • MIKES (FI),
  • NPL (GB),
  • TUBITAK (TK)

Abstract

Some national laboratories of metrology carry out the continuous expansion method to ensure measurements traceability for low absolute pressure. This method implies to generate a reference molar gas flow rate ranging from 4 × 10-12 mol·s-1 to 4 × 10-7 mol·s-1. To improve calibrations uncertainties for pressures below 10-3 Pa, Laboratoire national de métrologie et d’essais (LNE) had to initially design a primary reference for gas flow measurement in the aforementioned range, with an expected expanded uncertainty better than 1%. With the gas flowmeter, it will also be possible to calibrate reference leaks, which is an usual activity of the pressure department of the LNE, for the leaks with reference to vacuum between 4 × 10-12 mol·s-1 and 4 × 10-7mol·s-1 (from 1×10-8 Pa·m3·s-1 to 1×10-3 Pa·m3·s-1) and leaks of the cooling agent R-134a with reference to atmospheric pressure between 3×10-9 mol·s-1 and 2 × 10-8 mol·s-1 (from 10 g per year to 60 g·per year). The calibration results of a capillary leak are compared with the pressure rise calibration method, usually performed for this kind of instrument. An uncertainty budget on the gas flow measurement is established for this calibration and applied to the continuous expansion method.

Key words

constant pressure flowmeter
gas flow rate
continuous expansion method
low absolute pressure
reference leak

Abstract

Within the research project “surface activity analysis”, stretching over different metrological and technological topics, mass and nanotechnology for instance, improvements and adaptation have been carried out on different surface analysis devices in laboratories. The goal of this paper is to propose a review of the different developed devices, describing their main improvements for the past four years and to present the experimental results they produced.

Key words

mass metrology
nanodimentional metrology
surface characterization
sorption phenomena
roughness

Abstract

The kilogram is still defined in terms of an artefact, namely, the same prototype sanctioned by the 1st CGPM in 1889. It has three main limitations: available in one place, not really invariant in terms of physical mass and not universal as based on an artefact. The definition of the mass unit could be revised as early as 2011 by basing it on exactly fixed value of a fundamental constant of nature. Thus, the possibility of redefining the kilogram in function of a true natural invariant has been discussed for about 30 years. In this context, the French metrology decided in 2002 to undertake the realisation of a watt balance experiment aiming at linking the kilogram to the Planck constant. The adoption of a new definition of the kilogram based on an atomic or a fundamental physical constant has to take its dissemination into account by avoiding great change for the accredited institutes and most of users. Of course, this will have consequences for the transfer mass standards used by the National Institutes of Metrology.

Key words

references and standards
units of measurement
kilogram
watt balance
silicon single crystal
planck constant
avogadro constant
dissémination

Abstract

The design of a watt balance experiment requires skills in several scientific fields and needs to carry out numerous studies about every element of this experiment. That can be illustrated by the experimental study presented in this article. In order to have a single point of application of a weight and an electromagnetic force balancing this weight, a system of double gimbals with flexure pivots was made out of copper-beryllium alloy. It allows the articulation of the suspensions of the mass and coil generating the electromagnetic force round four coplanar axes which intersect in one point (virtual centre of rotation). The static characteristics of these elastic pivots have been studied in terms of stiffness and elasticity limit. In addition, the study of the dynamic behaviour under vacuum of this device has been carried out in terms of resonance frequency, damping due to internal frictions and coupling between the two systems of gimbals.

Key words

flexure pivot
stiffness
gimbals
watt balance
copper-beryllium alloy

Abstract

Air velocity is a quantity often used in specifications of industrial processes or buildings. In these applications, the velocity is generally below 1 m·s-1, the air temperature can be different from ambient one and the air can flow in any direction whatever. Furthermore, to reach minimum uncertainty measurements, a minimum calibration uncertainty of the used anemometer is needed as well as a calibration as close as possible to measurements conditions. To answer these needs, CETIAT has built a new anemometer calibration test rig. Its evaluation is presented in terms of stability, homogeneity on humidity, temperature and velocity fields as well as calibration uncertainty.

Key words

anemometer
low air velocity
wind-tunnel
calibration
uncertainty
laser doppler velocimetry

Abstract

The smallest mass standard sold until now had a nominal value of one milligram. In order to address emerging needs, the joint LNECNAM metrology laboratory decided to produce and calibrate micromass standards with nominal values down to 100 µg. These standards were developed, then tested through multiple comparisons. They have since been qualified and calibrated through a weighing design, repeatedly and over an extended period of time, so as to establish their stability with respect to oxidation and harmlessness of the handling and storage procedures associated with their use. After five successive calibrations no significant drift was found. Finally, in order to enhance this development, the laboratory obtained an extension of its accreditation to perform mass calibration allowing the extension of the lower limit of the scope of accreditation from 1 mg down to 100 µg.

Key words

microweight
micro-mass standard
submilligram
sensitivity error of mass comparators

Abstract

The national accelerometry references in France are provided by the LNE. Such traceability to national standards is essential for industrial organisations using processes in which an understanding of acceleration related parameters is of primary importance in terms of quality and safety. These fields include the armaments, nuclear, aerospace and automotive industries. The calibration of reference accelerometers for industries and other laboratories has been carried out on the LNE site at Trappes since 2006, using an absolute method involving a Michelson laser interferometer in accordance with standard ISO 16063. The bench used, which is described in “Transfert of the french accelerometry reference from CEA/Cesta to LNE” (RFM n° 10, 2007) is however of an old design and an upgrading program has been drawn up and carried out. This article describes the upgrade of this bench and the improvements. The characteristics of the components of the bench are described. These are the laser interferometer, the shaker and the acquisition and analysis system. In order to cover requirements for traceability chains for vibration frequencies below 10 Hz, a specific shaker for low frequencies has been sourced. Metrological approval was based on the consistency achieved between the calibration results for given accelerometers obtained using the new bench and those obtained using the original bench and on the interlaboratory comparisons.

Key words

accelerometer
vibration
calibration