The purpose of this work is to propose the implementation of methodology for high-dose measurements using traceable dosimeters related to the international metrology system, and to establish in the country, a standard for high-dose related to industrial irradiation facilities and research irradiators.

As part of the cooperation between two National Standardizing Institutes, Istituto Elettrotecnico Nazionale "Galileo Ferraris" (IEN) and National Institute of Metrology, Standardization and Industrial Quality (Inmetro), a colorimetric material characterization study has been initiated in 1999. With the main purpose of check the preliminary performance of the reference system used in the Radiometry Laboratory of Inmetro, four color samples were measured. On the first stage, the characterization of the samples was done at the IEN using a special goniophotometer, which doesn't need calibration of the detector and use an absolute measurement technique. Spectral measurements were made on typical configurations of lighting and reflecting conditions for colorimetric characterization of materials, 0/45 and 45/0. Photometric measurements were carried out by using a V(λ) filter in front of the detector and an illuminant A source at incident angles 0° and 45°. In the colorimetric and photometric cases, the results of measurements were respectively the three chromaticity coordinates calculated by the reflection factor (ρ), and the luminance associated to each direction. On the second and actual stage, measurements have been realized using an experimental set up for spectral reflectance and transmittance measurements at Inmetro. This work presents the results of measurements made by IEN.

The uncertainty for methylmercury determination in fish samples by cold vapor atomic absorption spectrometry technique was estimated based in the guide for quantifying uncertainty in analytical measurement of EURACHEM and ISO to the expression of uncertainty in measurement. The expanded uncertainty (9,5%) was obtained with 95% confidence level (k = 2).

The calibration process of a Fizeau interferometer using a liquid reference plane in an accredited secondary laboratory is presented. Influence factors involved, mainly vibration effects, are considered. The interferograms obtained, are then processed by two means: with self- developed software, based on mathematical morphology theory; and with free available web software. For validation, the results of measurement are compared with two previous calibrations made with commercial interferometers. An uncertainty of 26 nm is associated to the calibration process.

The organizations responsible for the maintenance of the measuring standards according the SI at international, regional and national levels are facing new challenges. A worldwide efficient and transparent metrology requires a new model of organization. The authors give an overview of the actual challenges and explain their thinking about where to go and how to built up it in the future.