8 research outputs found
Formations en « Instrumentation-Mesure-Qualité » pour des métiers à haute technologie
Devant les exigences métrologiques spécifiques des métiers à haute technologie, et afin de répondre efficacement et de manière cohérence à l’émergence des besoins en termes de formation dans le domaine de l’instrumentation, de la mesure et de la qualité, le Conservatoire National des Arts et Métiers (Cnam) propose pour cette spécialité de dimension transversale forte, des modules d’enseignement (niveaux I à III, en formation initiale, en hors temps ouvrable, en formation continue ou en alternance) dans les grandes thématiques du Cnam (industrie, santé, environnement, qualité...)
Transitions hyperfines de l'iode moleculaire au service de la metrologie des frequences optiques
SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Caractérisation du rendu des couleurs des nouvelles sources (les diodes électroluminescentes)
PARIS-CNAM (751032301) / SudocSudocFranceF
Visual experiment on LED lighting quality with color quality scale colored samples
International audienceA psychophysical experiment developed to evaluate light quality of Light Emitting Diodes (LEDs) is described. It is based on coloured samples used in the “Color Quality Scale” (CQS) proposed by the NIST to replace the “Colour Rendering Index” (CRI). Predictions of the CQS and results from visual measurements are compared
MESURES OPTIQUES POUR LA CARACTERISATION D’ECLAIRAGES A LED
International audienceNEOLUX, a French company specialized in the development of LED lightings, built a photometry laboratory for the complete characterization of luminaries. During the metrological evaluation process of its equipments, the measurement accuracy of portable spectroradiometers was studied by comparison with instruments from the French national metrology institute called “Laboratoire commun de métrologie LNE-Cnam”. Huge measurement differences were observed between the portable spectroradiometers.NEOLUX, société française spécialisée dans la conception d’éclairages à LED, s’est dotée d’un laboratoire de photométrie pour la caractérisation complète de luminaires. Dans le cadre de l’évaluation métrologique de ses équipements, l’exactitude de mesure de spectroradiomètres portatifs a été étudiée par comparaison à des équipements du Laboratoire Commun de Métrologie LNE-Cnam. D’importants écarts de mesures entre les spectroradiomètres portatifs ont été observés
The synthetic double wavelength technique: a simple robust method for thermodynamic temperature determination
International audienceThis paper describes a new relative technique developed at LNE-Cnam, for the determination of the thermodynamic temperature of blackbodies without recourse to a radiometric reference. This technique is referred to as the 'synthetic double wavelength technique' (SDWT) as it is considered to be a particular case of the 'double wavelength technique' (DWT). It offers a new experimental technique for the determination of the thermodynamic temperature at high temperature and as such a new means for the mise-en-pratique of the new definition of the kelvin achievable by any national metrology institute provided a multi-wavelength radiation thermometer combining large and narrow bandwidths is available. In this work, a first experimental implementation of this technique based on a wavelength-tuneable spectroradiometer providing both narrowband and broadband signals with the particularity of the broadband signal being virtually synthesised from the spectral distribution of the narrowband signals sampled over a wide spectral range. SDWT determination of the thermodynamic temperature of a blackbody at 2760 K was performed with a level of uncertainty that confirms the promising capabilities of this technique
A high resolution set up devoted to the measurement of the Bidirectional Reflectance Distribution Function around the specular peak, at LNE-CNAM
We see objects because they reflect light. This reflected light contains information that allows us not only identify the shape of the object but also its appearance. The overall appearance of an object is a combination of different visual attributes like gloss, texture, color or transparency, which are produced by the interaction between the object, the light falling upon it and the visual system [1].
Our interest in this article is to characterize the gloss of a surface. Our approach is the measurement of the Bidirectional Reflectance Distribution Function (BRDF) of the surface in, and around the specular direction, where the specular peak is located. For this, we developed a dedicated gonioreflectometer with a very high angular resolution. In this paper we present the equipment and measurements made on different surface
A New Optical Wavelength Ratio Measurement Apparatus: The Fringe Counting Sigmameter
International audienceA new, compact and achromatic Michelson-type interferometer with a variable path difference is presented. This "fringe-counting" sigmameter allows measurement of optical wavelength ratios between a laser of unknown wavelength and a reference laser of known wavelength. This apparatus, maintained in a vacuum, measures interference order variations in two stages: integer counting of around 400 000 and fractional counting (also called "excess fraction") with an uncertainty of 10. From these measurements, this "sigmameter" can determine laser wavelength from 0.36 m to 1.5 m with an accuracy of 1.10 using a reference stabilized He-Ne laser