Publications

MERLET S., BODART Q., MALOSSI N., LANDRAGIN A., PEREIRA DOS SANTOS F., GITLEIN O. et TIMMEN L., “Comparison between two mobile absolute gravimeters: optical versus atomic interferometers”, Metrologia, 47, 2010, L9–L11.

MEURY P.A., MOLINS R. et GENEVÈS G, “Metallurgical characte-rization of materials for the reference mass standard of the French watt balance experiment”, Metrologia, 47, 2010, 659-669.

PINOT P., GENEVÈS G. et HIMBERT M., « Prototype du kilogramme ou/et constante physique fondamentale :La dissémination de l’unité de masse », Revue française de métrologie, 22, 2010, 3-18.

PINOT P., MACÉ S., GENEVÈS G., GOURNAY P., HADDAD D., LECOLLINET M., VILLAR F. et HIMBERT M., « Etude de lames flexibles en cuivre-béryllium pour l’expérience française de balance du watt », Revue française de métrologie, 21, 2010, 9-21.

Communications

MERLET S., BODART Q., CHAUVET A., LANDRAGIN A. et PEREIRA DOS SANTOS F., “Accuracy of a cold atom gravimeter”, Frontiers in Matter Wave Optics (FOMO 2010), Crète, Grèce, 6-11 avril 2010.

BIELSA F., “Present status of the LNE watt balance”, CCEM WKG Meeting, Daejon, Corée du Sud, 12 juin 2010.

GENEVÈS G, “The e-MASS project”, CCEM WKG Meeting, Daejon, Corée du Sud, 12 juin 2010.

BIELSA F.,. EICHENBERGER A., GILBERT O., JUNCAR P. et GENEVÈS G., “Characterisation of the coil displacement in the LNE and METAS watt balances”, Conference on Precision Electromagnetic Measurements (CPEM 2010), Daejeon, Corée du Sud, 13-18 juin 2010.

GENEVÈS G., VILLAR F., BIELSA F., GILBERT O., EICHENBERGER A., BAUMANN H., D'AGOSTINO G., MERLET S., PEREIRA DOS SANTOS F., PINOT P. et JUNCAR P., “The e-mass euramet joint research project: the watt balance route towards a new definition of the kilogram”, Conference on Precision Electromagnetic Measu-rement (CPEM 2010), Daejon, Corée du Sud, 13-18 juin 2010.

GILBERT O., BIELSA F., JUNCAR P., EICHENBERGER A. et GENEVÈS G. , “Optical alignment tools for the LNE and METAS watt balance projects”, Conference on Precision Electro-magnetic Measurements (CPEM 2010), Daejeon, Corée du Sud, 13-18 juin 2010.

MERLET S. D’AGOSTINO G., GERMAK A., BAUMANN H., BODART Q., LOUCHET A., LANDRAGIN A. et PEREIRA DOS SANTOS F., “Comparison of 3 absolute gravimeters based on different methods for the e-MASS project”, Conference on Precision Electromagnetic Measurements (CPEM 2010), Daejeon, Corée du Sud, 13-18 juin 2010.

VILLAR F., GENEVÈS G. et DAVID J., “Determination and minimization of parasitic forces and moments in the static step of the LNE watt balance”, CPEM 2010, Daejon, Corée du Sud, 13-18 juin 2010.

MERLET S., LANDRAGIN A. et PEREIRA DOS SANTOS F., « SYRTE cold atom gravimeter », Séminaire au KRISS, Corée du Sud, 17 juin 2010.

JIANG Z., TISSERAND L., KESSLER-SCHULZ K.U., SCHULZ H. R., PALINKAS V., ROTHLEITNER C., FRANCIS O., JOUSSET P., LEQUIN D., MERLET S., MÄKINEN J., COULOMB V et BECKER M., “Preliminary results of the BIPM relative gravity measurement campaign during the 8th international comparison of absolute gravimeters (2009)”, TGSMM 2010, St Petersbourg, Russie, 22-25 juin 2010.

MERLET S., BODART Q., LOUCHET-CHAUVET A., LANDRAGIN A. et PEREIRA DOS SANTOS F., « Exactitude d’un gravimètre atomique », PAMO 2010, Orsay, France, 29 juin-2 juillet 2010.

PINOT P., MACÉ S. et GENEVÈS G., « Comportement statique et dynamique de matériaux utilisés comme pivots flexibles », Matériaux 2010, Nantes, France, 18-22 octobre 2010.

Publications

BICH W., D’AGOSTINO G., PENNECCHI F. et GERMAK A., “Uncertainty due to parasitic accelerations in absolute gravimetry”, Metrologia, 48, 2011, 212-218.

D’Agostino G., Merlet S., Landragin A. et Pereira Dos Santos F., “Perturbations of the local gravity field due to mass distribution on precise measuring instruments: a numerical method applied to a cold atom gravimeter”, Metrologia, 48, 2011, 299-305.

LOUCHET-CHAUVET A., FARAH T., BODART Q, CLAIRON A., LANDRAGIN A., MERLET S. et PEREIRA DOS SANTOS F, “Influence of transverse motion within an atomic gravimeter”, New J. of Phys., 13, 2011, 065025.

LOUCHET-CHAUVET A., MERLET S., BODART Q, LANDRAGIN A., PEREIRA DOS SANTOS F., BAUMANN H., D’AGOSTINO G. et ORIGLIA C., “Comparison of 3 absolute gravimeters based on different methods for the e-MASS project”, IEEE Trans. on Instrum. Meas., 60, 2011, 2527-2532.

PINOT P. et GENEVES G., “Numerical simulation for designing tuned liquid dampers to damp out double pendulum oscillations”, Meas. Sci. Technol., 22, 2011, 065103.

Communications

MERLET S., FARAH T., LOUCHET-CHAUVET A., CLAIRON A., LANDRAGIN A. et PEREIRA DOS SANTOS F., “Continuous g monitoring with atom interferomerty”, IFCS-EFTF 2011, San Francisco, Etats-Unis d’Amérique, 1-5 mai 2011.

MERLET S., “WP3: Gravimetry”, JRP e-MASS dissémination meeting, Watt Balance Technical Meeting (WBTM), Metas, Bern, Suisse, 22 juin 2011.

BIELSA F., « Capteurs optiques pour l’expérience de balance du watt du LNE », 15e Congrès international de métrologie, Paris, France, 3-6 octobre 2011.

GENEVES G., « Une méthode de détermination des effets de désalignement dans les expériences de balance du watt », 15e Congrès international de métrologie, Paris, France, 3-6 octobre 2011.

JIANG Z., PALINKAS V., FRANCIS O., BAUMANN H., BECKER M., COULOMB A., JOUSSET P., KESSLER-SCHULZ K.U., LEQUIN D., MÄKINEN J., MERLET S., SCHULZ H.R., SVITLOV S., TISSERAND L. et WANG L., “Accurate gravimetry at the BIPM watt balance bite”, IUGG/IAG 2011, Melbourne, Australie, 28 juin - 7 juillet 2011.

PINOT P. et GENEVES G., « Amortisseurs à ballottement de liquide pour l’expérience de balance du watt », 15e Congrès international de métrologie, Paris, France, 3-6 octobre 2011.

Publications

OUEDRAOGOA K., TOPSU S., GAYHMOUNI J., CHASSAGNE L., ALAYLI Y., JUNCAR P., GOURNAY P., BIELSA F. et GENEVÈS G., “Accurate ellipsometric magnetic-field sensor used to align the watt balance magnetic circuit of the French National Metrology Institute”, Sensors and Actuators, A, 175, 2012, 9-14.

Communications

MERLET S., FARAH T., GUERLIN C., CLAIRON A., LANDRAGIN A. et PEREIRA DOS SANTOS F., « Gravimètre atomique absolu », Séminaire Géosciences Montpellier, Montpellier, France, 2 février 2012.

GUERLIN C., FARAH T., CHAUVET-LOUCHET A., CLAIRON A., LANDRAGIN A., MERLET S. et PEREIRA DOS SANTOS F., “High sensitivity absolute atom gravimeter”, QIM 2012, Berlin Allemagne, 19–21 mars 2012.

FARAH T., GUERLIN C., LANDRAGIN A., MERLET S. PEREIRA DOS SANTOS F., BOUYER PH., AUGUSTE M., CAVAILLOU A., BOYER D., POUPENEY J., SUDRE CH. et GAFFET S., “Absolute atom gravimeter at LSBB : a first step toward MIGA”, i-DUST, Apt, France, 9–11 mai 2012.

PEREIRA DOS SANTOS F., “The LNE-SYRTE atom gravimeter”, Symposium on Geodesy with Inertial Quantum Sensors, Hanover, Allemagne, 9–12 juin 2012.

BIELSA F., “The LNE watt balance: progress report”, CCEM working group on electrical methods to monitor the kilogram, Washington, États-Unis, 30 juin 2012.

THOMAS M., ESPEL P., BIELSA F., JUNCAR P., PINOT P. et GENEVÈS G., “Present status of the LNE watt balance”, Conference on Precision Electromagnetic Measurements (CPEM-2012), Washington DC, États-Unis, 1–6 juillet 2012.

BIELSA F., « Balance du watt », Journée des métrologues, Paris, France, 17 septembre 2012.

GENEVÈS G., “LNE watt balance”, Kick-off meeting projet KNOW, Trappes, France, 26–27 septembre 2012.

GENEVÈS G., “LNE watt balance”, CCM workshop on the mise en pratique of the new definition of the kilogram, BIPM, Sèvres, France, 21–22 novembre 2012.

GENEVÈS G., « Une détermination de la constante de Planck en vue de la redéfinition du kilogramme », Journée nationale du réseau Mesures, Modèles et Incertitudes, Orsay, France, 23 novembre 2012.

Publications

FRANCIS O. et al., « The European comparison of absolute gravimeters 2011 (ECAG-2011) in Walferdange, Luxembourg: results and recommandations », Metrologia, 50, 3, 2013, 257-268, DOI: 10.1088/0026-1394/50/3/257.

JIANG Z., PALINKAS V., FRANCIS O., BAUMANN H., MAKINEN J., VITUSHKIN L., MERLET S., TISSERAND L., JOUSSET P., ROTHLEITNER C., BECKER M., ROBERTSON L. et ARIAS E.F., “On the gravimetric contribution to the redefinition of the kilogram”, Metrologia, 50, 2013, 452-471, DOI: 10.1088/0026-1394/50/5/452.

Communications

MERLET S., « Redéfinition du kilogramme, balance du watt et gravimétrie », Séminaire Temps-Espace, Observatoire de Paris, France, 8 avril 2013.

FARAH T., GUERLIN C., LANDRAGIN A., MERLET S., PEREIRA DOS SANTOS F., Pushing the limits of an atom gravimeter, ECAMP11, Aarhus, Danemark, 24–28 juin 2013.

MERLET S., FARAH T., LANDRAGIN A., PEREIRA DOS SANTOS F., “Mobile LNE-SYRTE Cold Atom Gravimeter - Comparison and on field measurement “, TGSMM, Saint Pétersbourg, Russie, 17–20 septembre 2013,

THOMAS M. et al., « Une méthode de mesure de la constante de Planck : la balance du watt », Congrès International de Métrologie, Paris, France, 7–10 octobre 2013.

MERLET S., FARAH T., LAUTIER J., LANDRAGIN A. et PEREIRA DOS SANTOS F., “Performances and capabilities of the mobile LNE-SYRTE Cold Atom Gravimeter”, AGU Fall Meeting, San Francisco, Etats-Unis, 9–13 décembre 2013.

Publications

FARAH T., GILLOT P., CHENG B., LANDRAGIN A., MERLET S. et PEREIRA DOS SANTOS F., “Effective velocity distribution in an atom gravimeter: Effect of the convolution with the response of the detection”, Phys. Rev. A, 90, 2014, DOI: 10.1103/PhysRevA.90.023606.

FARAH T., GUERLIN C., LANDRAGIN A., BOUYER PH., GAFFET S., PEREIRA DOS SANTOS F. et MERLET S., “Underground operation at best sensitivity of the mobile LNE-SYRTE Cold Atom Gravimeter”, Gyroscopy and Navigation 5, 2014, 266-274, DOI: 10.1134/S2075108714040051.

GILLOT P., FRANCIS O., LANDRAGIN A., PEREIRA DOS SANTOS F. et MERLET S., “Stability comparison of two absolute gravi-meters: optical versus atomic interferometers”, Metrologia 51, 5, 2014, L15-L17, DOI: 10.1088/0026-1394/51/5/L15

JIANG Z., PALINKAS V., FRANCIS O., MERLET S. et al., “Accurate gravimetry at the BIPM Watt balance site”, Earth on the Edge: Science for a Sustainable Planet, Springer-Verlag Berlin Heidelberg, 139, 2014, 371-376.

MERLET S., GILLOT P., FARAH T., BODART Q., LE GOUËT J., CHEINET P., GUERLIN C., LOUCHET-CHAUVET A, MALOSSI. N., KOPAEV A., FRANCIS O., D'AGOSTINO G., DIAMENT M., GENEVES G., CLAIRON A., LANDRAGIN A. et PEREIRA DOS SANTOS F., « Détermination de l'accélération de la pesanteur pour la balance du watt du LNE », Revue française de métrologie, 36, 4, 2014, 11-27, DOI: 10.1051/rfm/2014013.

THOMAS M., ESPEL P., BRIAND Y., GENEVÈS G., BIELSA F., PINOT P., JUNCAR P. et PIQUEMAL F., “Minimization of the coil movement of the LNE watt balance during weighing mode and estimation of parasitic forces and torques involved”, Metrologia, 51, 2014, 54, DOI: 10.1088/0026-1394/51/2/S54.

Communications

JIANG Z., PALINKAS V., FRANCIS O., MERLET S. et al., “Accurate gravimetry at the BIPM Watt balance site”, Earth on the Edge: Science for a Sustainable Planet - International Association of Geodesy Symposia 139, Melbourne, Australie, 28 juin-2 juillet 2014.

MERLET S., GILLOT P., CHENG B., LANDRAGIN A. et PEREIRA DOS SANTOS F., “Wavefront aberration bias in LNE-SYRTE Cold Atom Gravimeter”, Meeting of IAC, kNOW, and CCM WGR-kg, Rio de Janeiro, Brésil, 22 août 2014.

THOMAS M., ESPEL P., BIELSA F., PINOT P., JUNCAR P., GENEVÈS G. et PIQUEMAL F., “Progress report on the LNE watt balance”, CCEM WGkg meeting, Rio de Janeiro, Brésil, 23 août 2014.

ARNOLD T., BAUMANN H., BETTIN H., BIELSA F., EICHENBERGER A., KURAMOTO N., MANA G., MASSA E., MERLET S., PEREIRA DOS SANTOS F., PICARD A., PINOT P. et PIQUEMAL F., “European Metrology Research Program: Advances on the Realization of the kilogram Redefinition”, Conference on Precision Electromagnetic Measurements (CPEM 2014), Rio de Janeiro, Brésil, 24-29 août 2014, DOI: 10.1109/CPEM.2014.6898441.

MERLET S., GILLOT P., CHENG B., LANDRAGIN A. et PEREIRA DOS SANTOS F., “Continuous free fall acceleration determination for the LNE Watt balance”, Conference on Precision Electromagnetic Measurements (CPEM 2014), Rio de Janeiro, Brésil, 24-29 août 2014, DOI: 10.1109/CPEM.2014.6898411.

THOMAS M., ESPEL P., BIELSA F., GENEVÈS G., PIQUEMAL F., JUNCAR P. et PINOT P., “Progress report of the LNE watt balance”, Conference on Precision Electromagnetic Measu-rements (CPEM 2014), Rio de Janeiro, Brésil, 24-29 août 2014.

MERLET S., GILLOT P., CHENG B. et PEREIRA DOS SANTOS F., “Gravimetry for the LNE Watt balance”, Géodésie Géophysique Colloque G2, Strasbourg, France, 17-19 novembre 2014.

MERLET S., GILLOT P., CHENG B. et PEREIRA DOS SANTOS F., « Gravimetre atomique du SYRTE – Performances - mesures au LSBB », Workshop MIGA, LSBB Rustrel, France, 28 novembre 2014.

Publications

CHENG B., GILLOT P., MERLET S. et PEREIRA DOS SANTOS F., “Influence of chirping the Raman lasers in an atom gravimeter: Phase shifts due to Raman light shift and to the finite speed of light”, Physical Review A, 92, 2015, DOI: 10.1103/PhysRevA.92.063617.

JIANG Z., PALINKAS V., FRANCIS O., MERLET S., BAUMANN H., BECKER M., JOUSSET P., MÄKINEN J., SCHULZ H.R, KESSLER-SCHULZ K.U., SVITLOV S., COULOMB A., TISSERAND L., HU H.  et ROTHLEITNER CH., “Accurate gravimetry at the BIPM watt balance site”, Chapter “Earth on the Edge: Science for a Sustainable Planet”, Book Series: International Association of Geodesy Symposia,”, 139, 371-376, 2015, DOI: 10.1007/978-3-642-37222-3_49.

THOMAS M., ESPEL P., ZIANE D., PINOT P., JUNCAR P., PEREIRA DOS SANTOS F., MERLET S., PIQUEMAL F. et GENEVÈS G., “First determination of the Planck constant using the LNE watt balance”, Metrologia, 52, 2015, 433-443, DOI: 10.1088/0026-1394/52/2/433.

Communications

THOMAS M., ESPEL P., BIELSA F., PINOT P., JUNCAR P., GENEVÈS G. et PIQUEMAL F., “A determination of the Planck constant in air by the LNE watt balance”, CODATA workshop, Eltville, Allemagne, 2-6 février 2015.

CHENG B., GILLOT P., LANDRAGIN A., MERLET S.  et PEREIRA DOS SANTOS F., “Residual clock effect in Cold Atom Gravimeter”, AG First-TF, Besançon, France, 16 mars 2015.

GILLOT P., CHENG B., LANDRAGIN A., MERLET S. et PEREIRA DOS SANTOS F., “Residual clock effect in cold atom gravimeter”, Coloq14, Rennes, France, 6-9 juillet.

LANDRAGIN A., DUTTA I., GILLOT P., KOHLHAAS R., LAUTIER J., MEUNIER M., SAVOIE D., CHENG B., FANG B., GARRIDO ALZAR C., GEIGER R., MERLET S. et PEREIRA DOS SANTOS F., “Atom Interferometry for inertial sensors: fundamental and practical sensitivity limits”, 23e Congrés général de la SFP, Strasbourg, France, 24-25 août 2015.

PINOT P., ESPEL P., THOMAS M., ZIANE D. et PIQUEMAL F., « Expérience française de balance du watt: composantes d’incertitude associées à l’étalon de masse pour la détermination de la constante de Planck », 17e Congrès international de métrologie, Paris, France, 21-24 septembre 2015, DOI: 10.1051/metrology/20150018001.

PINOT P., LIU Y., ESPEL P., THOMAS M., ZIANE D. et PIQUEMAL F., « Expérience française de balance du watt : conception d’un fléau de balance monobloc et étude de son comportement mécanique », 17e Congrès international de métrologie, Paris, France, 21-24 septembre 2015, DOI: 10.1051/metrology/20150018002.

SILVESTRI Z. et DAVIDSON S., “How to disseminate the new mass unit?”, 17e Congrès international de métrologie, Paris, France, 21-24 septembre 2015, DOI: 10.1051/metrology/20150018003.

GILLOT P., CHENG B., MERLET S. et PEREIRA DOS SANTOS F., « Des performances ultimes d'un gravimètre atomique transporbale à l'hybridation avec un accéléromètre classique », Workshop Atomes froids et applications embarquées, Toulouse, France, 9 décembre 2015.

Many industrial processes emit infrasound or ultrasound (wind turbines, heat pumps, ultrasonic cleaning systems, etc.). However, the mechanism for perceiving sounds outside the audible range is not currently well understood. Manufacturers and operators of installations that emit this type of sound need noise emission regulations to be well-founded and not unnecessarily restrictive: it is therefore necessary to define rational, evidence-based criteria to prevent the risks associated with these sounds.

In order to define criteria for limiting exposure and protecting the population, it is necessary to have a metrological infrastructure with reference standards, calibration methods and appropriate measuring equipment to quantify the harmful effects of ultrasound and infrasound.

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 AND RESULTS

This European project comprised five technical work packages:

1 - Measurement technology for determination of brain responses to non-audible sound

2 - Measurement requirements for non-audible sound

3 - Brain response thresholds and hearing thresholds for non-audible sound

4 - Design of a wideband universal ear simulator

5 - Test and validation of the universal ear simulator and determination of reference data

LNE participated in the fourth work package, which focused on developing a tool to simulate the acoustic behaviour of the ears of newborns, children and adults. The aim was to be able to calibrate audiometers, adjust hearing aids (prostheses) and detect hearing loss from an early age.

Initially, the work consisted of establishing specifications in line with user needs, developing a design methodology to highlight the key parameters, and gathering the information necessary for this design through an extensive literature review. Based on the results of the literature review, five age groups were established: newborns, 1-3 months, 3-6 months, 3-24 months, 2-7 years, and adults.

Vue en coupe du simulateur d'oreille pour nouveaux nés.
Cross-sectional view of the newborn ear simulator. 𝘛𝘩𝘦 𝘶𝘱𝘱𝘦𝘳 𝘰𝘱𝘦𝘯𝘪𝘯𝘨 𝘳𝘦𝘱𝘳𝘦𝘴𝘦𝘯𝘵𝘴 𝘵𝘩𝘦 𝘳𝘦𝘧𝘦𝘳𝘦𝘯𝘤𝘦 𝘱𝘭𝘢𝘯𝘦 𝘰𝘧 𝘵𝘩𝘦 𝘦𝘢𝘳 𝘤𝘢𝘯𝘢𝘭, 𝘢𝘯𝘥 𝘢 ¼″ 𝘮𝘪𝘤𝘳𝘰𝘱𝘩𝘰𝘯𝘦 𝘪𝘴 𝘯𝘰𝘳𝘮𝘢𝘭𝘭𝘺 𝘱𝘰𝘴𝘪𝘵𝘪𝘰𝘯𝘦𝘥 𝘰𝘯 𝘵𝘩𝘦 𝘶𝘯𝘥𝘦𝘳𝘴𝘪𝘥𝘦 𝘵𝘰 𝘮𝘦𝘢𝘴𝘶𝘳𝘦 𝘢𝘤𝘰𝘶𝘴𝘵𝘪𝘤 𝘱𝘳𝘦𝘴𝘴𝘶𝘳𝘦 𝘴𝘪𝘨𝘯𝘢𝘭𝘴, 𝘴𝘪𝘮𝘶𝘭𝘢𝘵𝘪𝘯𝘨 𝘵𝘩𝘦 𝘦𝘢𝘳𝘥𝘳𝘶𝘮.

Following completion of this initial task, ear simulators were designed for each of the five age groups. This task was accomplished using both analytical and numerical acoustic modelling.

For cost reasons, only the prototype for the newborn group was manufactured. The prototypes were qualified in parallel by four national metrology laboratories, including the LNE. This qualification mainly consisted of measuring the acoustic transfer impedance of the simulator (ratio between the input flow and the acoustic pressure on the simulator's microphone) and comparing it with that calculated by the LNE during the design phase. The results of this qualification show measurements that are well aligned with the theoretical curve over a wide frequency range, except at high frequencies (above 6 kHz).

 

Prototypes de simulateurs d'oreille néonatal
Prototypes of neonatal ear simulators (photo from the Ears project)

PUBLICATIONS ET COMMUNICATIONS

BARHAM R., OLSEN E.S., RODRIGUES D., BARRERA-FIGUEROA S., SADIKOGLU E. and KARABÖCE B., “The calibration of a prototype occluded ear simulator designed for neonatal hearing assessment applications”, The Journal of the Acoustical Society of America, 2016, 140, 2, DOI: 10.1121/1.4960517.

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

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

RODRIGUES D., LAVERGNE T., FEDKE T., SANDERMANN OLSEN E., BARHAM R. and DUROCHER J.-., “Methodology of designing an ear simulator”, Internoise 2013, Innsbruck, Austria, 15-18 September 2013.

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

PARTNERS

National metrology institutes:

  • PTB (project coordinator),
  • NPL,
  • LNE,
  • DFM,
  • Tubitak UME,
  • BKSV-DPLA.

When this European project was launched, there was no coverage for metrological force measurement needs above 15 MN in Europe. This corresponds to industrial applications in many fields (mechanical engineering, construction, energy, etc.). To cover most of the requirements, it was estimated that it would be necessary to be able to measure up to 50 MN. This project focused on the study of “build-up systems” which are the combination of several force sensors in parallel in order to measure forces higher than those that each sensor can measure individually.

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 AND RESULTS

Référence à pyramide de capteurs de force du LNE
Reference using Buid-Up System

The LNE has long developed systems combining parallel force sensors called “Build-Up Systems” (BUS) used to calibrate force sensors between 500 kN and 9 MN. The work of this JRP focused on studying these systems and qualifying new force transfer standards. The reference pyramids, solutions implemented in the laboratory, were studied in particular in this project.

At the LNE, the BUS was only applied under increasing loads, meaning that it was not possible to determine the hysteresis of the sensors to be calibrated. For the LNE, this project was an opportunity to model the phenomena of hysteresis, creep, and relaxation in order to quantify the uncertainties of its BUS when used under decreasing loads.

 

Study of the behavior of Build-Up Systems

Various types of BUS in the meganewton range were studied, notably by cross-referencing measurements taken using different measurement benches implemented by the laboratories participating in the project. For the LNE-LCM, the good consistency between the individual calibration of the sensors in its BUS and their calibration in assembled position was confirmed up to 9 MN, demonstrating the absence of effects related to the introduction of forces and confirming the uncertainties announced by the laboratory.

 

Study of the effects of parasitic forces

Lateral forces

A 5 MN BUS capable of measuring lateral forces and moments superimposed on the main axial force was developed by INRiM based on the hexapod principle. At the same time, the calibration procedures for multi-component sensors were identified and an inter-laboratory comparison was carried out between PTB, LNE, and INRiM. The differences obtained show that the LNE-LCM test bench performs well, with low parasitic forces and consistent measurements for both vertical forces and superimposed parasitic forces.

Effect of eccentricity

On the other hand, the effect of an eccentricity between the force and the axis of the BUS. A series of measurements were taken by aligning and offsetting a sensor by 3 mm with a BUS. These showed that there is no significant effect on the LNE BUS. This confirms the uncertainties of the laboratory, which uses a device that ensures centering of around 0.1 mm for routine calibrations.

 

Effect of durations and loading mode

The initial aim of the work was to acquire data in order to better understand the behavior of force sensors in relation to preloads, creep, relaxation, and hysteresis.

Logiciel de calcul d'hystérésis et d'identification des paramètres des capteurs de force
Hysteresis calculation and parameter identification software

As part of this European project, a total of 229 tests were carried out using 44 different sensors covering ranges from 50 N to 5 MN. These tests focused on creep, zero return, and reversibility. Armed with this data, the objective was to develop numerical models to correct the effects associated with force sensor loading procedures. These effects include creep, zero drift (relaxation), and reversibility (or hysteresis). Hysteresis modeling software was developed. Modeling was defined for creep and relaxation.

 

Project outlook...

For the laboratory, the claimed uncertainties of the reference pyramids up to 9 MN have been confirmed as entirely justified, both in terms of internal stress transmission phenomena and sensitivity to parasitic forces. In addition, modeling of creep, relaxation, and hysteresis phenomena makes it possible to consider systematic corrections to the reference pyramids for measurements under decreasing loads. This will enable LNE-LCM, for forces above 500 kN and up to 9 MN, to determine the hysteresis of the sensors used by the laboratories and manufacturers it connects, and thus to better meet their needs.

 

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 August - 4 September 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, South Africa, 3-5 February 2014.

PARTNERS

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

The noise produced by machinery or equipment is a technical characteristic generally expressed in terms of acoustic power (power level in dB relative to a reference acoustic power of 10-12 watts). When this project was started, the experimental determination of power was based on acoustic pressure measurements taken using microphones. The acoustic power was then evaluated by calculation, under various assumptions and conditions that were not perfectly met. As a result, the connection to the international system of units was achieved by linking pressure levels through microphone sensitivity measurements. This resulted in a ‘true’ assessment of acoustic power being marred by all kinds of biases, uncorrected influencing factors and methodological errors. The situation was made even more complex by the fact that some of the acoustic power measurements used a method of comparison with reference sound sources, which were themselves calibrated using the pressure method and were quite sensitive to environmental conditions.

The aim of this project was therefore to develop and characterise a primary standard sound source and then disseminate it via transfer standards (which are the sound sources that were previously used as references). The application to machine noise was then to be carried out by developing new procedures for measuring sound power in different environments and evaluating the associated measurement uncertainties.

OBJECTIVES

Develop a reference sound source whose acoustic power can be calculated from measurements of vibration velocity, dimensions, and environmental air properties, with an uncertainty of 0.5 dB.

Measure the acoustic power of this reference sound source using sound intensity instruments calibrated in accordance with IEC 61043 and explain any deviation from the expected behaviour. This is necessary to distinguish the phase shift between the speed of sound and the acoustic pressure on the surrounding surface.

Develop methods for calibrating non-calculable sound sources by comparison with the reference sound source. The focus will be primarily on broadband sources, which generate sounds aerodynamically. Another aspect addressed is the development of a new concept for tonal sound sources.

Develop qualification procedures for measuring devices, analyse uncertainties associated with determining sound power in practice, and develop a substitute method using sound intensity for machine noise.

SUMMARY AND RESULTS

Exemple de source sonore de référence utilisée au LNE
Example of a reference sound source used as a transfer standard at the LNE.

Primary standard sound source

The objective of this part was to produce a primary standard for the acoustic watt in air. This is based on a baffled vibrating solid body (piston). The sound power of this device can be determined from the vibration speed of the body's surface, measured by laser interferometry, and several other variables such as static pressure and temperature. The various candidates for primary sources are based on two techniques: an electrodynamic pot or a loudspeaker ‘motor’. The electrodynamic pot is a vibration source commonly used in laboratories. It drives the movement of a metal piston. The latter must have as much overall movement as possible and as little parasitic movement as possible, due to its lack of rigidity and its natural modes/frequencies at high frequencies. The other method involves using a loudspeaker ‘motor’ that drives a lighter piston. Guiding the piston in a unidirectional and free movement is difficult to achieve. In this project, primary sources were developed by PTB, SP, INRiM and TUBITAK UME.

Diffusion of the ‘acoustic watt’ unit

The objective of this part was to develop a system for disseminating the acoustic watt unit using appropriate transfer standards. This made it possible to examine whether existing aerodynamic reference sound sources could be used as transfer standards. The answer was positive, provided that their sensitivity to atmospheric conditions was known. The uncertainty of the sound power emitted by the transfer standards was determined. The objective was for this uncertainty to be only slightly greater than the uncertainty of the primary standard. The LNE developed a scanning apparatus for automated measurement of acoustic power by measuring the acoustic pressure on a 2 m radius hemisphere centred on a reference source flush with the ground.

At LNE, unlike other partners, a single microphone is used, moved to each position by an automatic device and controlled by software that manages both the scanning device and the acoustic signal analyser acquisition. The first movement is made along a rail describing a 90° vertical arc. The second movement consists of moving this arc around a vertical axis to cover the entire hemispherical surface. A third movement moves the microphone along a 1 cm radius to evaluate the intensity in two stages.

"Scanning apparatus" du LNE : vue d'ensemble et détail de la tête de mesure
LNE scanning apparatus: overview (left) and detail of the measuring head (right)

Project website:

http://www.ptb.de/emrp/sib56-home.html

PUBLICATIONS AND COMMUNICATIONS

BREZAS S., CELLARD P., ANDERSSON H., GUGLIELMONE C. and KIRBAS C., “Dissemination of the unit Watt in airborne sound: aerodynamic reference sound sources as transfer standards”, INTER-NOISE 2016, Hamburg, Germany, 21-24 August 2016.

CELLARD P., ANDERSSON H., BREZAS S. and WITTSTOCK S., “Automatic sound field sampling mechanisms to disseminate the unit watt in airborne sound”, INTER-NOISE 2016, Hamburg, Germany, 21-24 August 2016.

Partners

The work was carried out as part of the European project JRP SIB56, which included the following national metrology laboratories:

  • PTB (DE),
  • INRIM (IT),
  • LNE (FR),
  • SP (SE),
  • 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