Abstract

The French National Metrology Laboratory, the LNE-LCM, uses a cryogenic radiometer as the basis for its optical radiation measurement scales. This instrument is an absolute radiometer operating at 4.2 K based on the electrical substitution method. It allows absolute measurements of the optical power of laser beams with a relative standard uncertainty in the range of 5 parts in 105. A new cryogenic radiometer was installed in the laboratory and the present paper describes its complete metrological characterization which allows to achieve this level of uncertainty.

Key words

optical radiation
cryogenic radiometer
primary reference
spectral responsivity

Abstract

Spectrophotometers allow measurement of the optical properties of materials such as transmittance or reflectance. They are used in many industrial fields: health, transport, energy. . . To ensure the traceability of the measurements through the calibration of transmittance and reflectance standards, the LNE uses spectrophotometers that are qualified along the lifetime of these instruments. We present the qualification steps. The results are used to evaluate the uncertainties. The procedure followed can be used as a guideline for spectrophotometer users who want to evaluate their measurement uncertainties.

Key words

spectrophotometer
transmittance
qualification
measurement uncertainty

The European project, coordinated by the SFI-Davos (Switzerland), aims to develop methods for measuring direct, diffuse and global solar spectral irradiance between 290 nm and 400 nm with an uncertainty of 1% to 2% and new instruments for rapid measurement of spectral irradiance (UV to TF spectroradiometers) to take into account rapid variations in atmospheric conditions (measurement duration less than 10 s and repetition time less than 1 min).

Objectives

Improved measurements of UV radiation from the solar spectrum reaching the ground

Estimation of uncertainties of matrix spectroradiometers

Development of a photodiode array spectroradiometer optimized for spectrum measurement between 290 nm and 400 nm and with minimization of stray light

Summary

Find here the detailled description of the project:

http://projects.pmodwrc.ch/env03/

Publications and communications

DUBARD J. et  ETIENNE R., “Monte Carlo uncertainty evaluation of UV solar spectral irradiance measurements using array spectroradiometer”, 7th Workshop on Ultraviolet radiation measurements (UVNET), Davos, Suisse, 27-28 août 2013.

DUBARD J., VALIN T., ETIENNE R. et EBRARD G., “EMRP-ENV03: Traceability for surface  spectral solar ultraviolet radiation”, 16e Congrès International de Métrologie, Paris, France, 7-10 octobre 2013, DOI: 10.1051/METROLOGY/201318001.

Partners

JRP-ENV03 partners:

  • SFI Davos (Switzerland),
  • EJPD/METAS (Switzerland),
  • PTB (Germany),
  • VSL (Netherlands),
  • CMI (Czech Republic),
  • LNE (France),
  • INRIM (Italy),
  • Aalto (Finland),
  • CMS (Austria),
  • Kipp&Zonen (Netherlands),
  • IMU (Austria).

Solid-state emitter-based lighting (LED type) is considered to be twice as efficient as that produced by conventional incandescent lamps. The generalisation of their use requires the development of metrological methods and instrumentation in order to characterise their performance in an univocal manner.

Objectives

Improve the qualification of LED (light-emitting diode) lighting: evaluate colour rendering metrics applied to LED-based lighting

Better qualify LED lighting: develop a basic model for predicting the visual comfort of LED lighting.

Summary

Find here the detailled description of the project:

http://www.m4ssl.npl.co.uk/

Publications and communications

RENOUX D., NONNE J. and SABOL D., “Contribution to the assessment and the improvement of colour rendering metrics of artificial light sources”, CIE 2012 – Lighting Quality and Energy Efficiency, Hangzhou, China, September 19th 2012.

ROSSI L, SIRAGUSA S., NONNE J. and RENOUX D., “Correlating eye movements with indoor visual comfort perception under artificial lighting”, 17th European Conference on Eyes Movements (ECEM), Lund, Sweden, August 11th-16th 2013.

NONNE J., RENOUX D. and ROSSI L., « Metrologie pour les éclairages à état solide », 16e Congrès International de Métrologie, Paris, France, October 7th-10th 2013, DOI: 10.1051/METROLOGY/201314004.

BAUMGARTNER H., RENOUX D., VASKURI A., PULLI T., POIKONEN T., KÄRHÄ P. and IKONEN E., “Lifetime projection of LED light sources”, Proceedings of the Finnish Physics Days, 2013, 10.18.

Partners

  • INRIM (Italy) : hosting a scientist (February-March-April 2012) to work on colour rendering.
  • SMU (Slovakia) : hosting a scientist (August-September-October 2012) to work on visual comfort metrics.
  • Mitsubishi Chemical : use of this company's LEDs and exchange on the results.

JRP-ENG05 partners :

  • VSL (Netherlands),
  • Aalto (Finland),
  • CMI (Czech Republic),
  • CSIC (Spain),
  • EJPD (Switzerland),
  • INRIM (Italy),
  • IPQ (Portugal),
  • LNE (France),
  • MKEH (Hungary),
  • NPL (United Kingdom),
  • PTB (Germany),
  • SMU (Slovakia),
  • SP (Sweden),
  • Trescal (Denmark),
  • CCR (Italy),
  • TU-IL (Germany),
  • UPS (France).