PHOTOMETRY, RADIOMETRY AND RADIOFREQUENCIES
The Laboratory of Photometry, Radiometry and Radiofrequencies has the incumbencies of materialize, maintain and disseminate of the measurement units of luminous intensity, illuminance, regular transmittance and regular reflectance, refractive index of aqueous solutions and road speed, and of develop and implement measurement new methods and capabilities.
The activities of the Laboratory have the following objectives:
- Guaranteeing the traceability of the units assigned to it, enabling its dissemination at national level;
- Participating in or coordinating R&D projects and interlaboratory comparisons;
- Supporting Legal Metrology.
Meet the ongoing project here.
The fields of activity of the Photometry, Radiometry and Radiofrequencies Laboratory, for which it has international recognition, are:
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- Luminous intensity from 5 cd to 1000 cd; illuminance from 5 lx to 1000 lx; responsivity of photometers, expressed in V/lx;
- Refractive indexes of liquid solutions between 1,332 98 and 1,580 00; saccharose or glucose mass fraction in aqueous solutions up to 85,00 cg/g; ethanol potential volume fraction in aqueous solutions up to 55 cL/L;
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- Road speed up to 350 km/h.
In an advanced stage of obtaining international recognition:
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- Regular transmittance between 0,01 and 0,90; regular reflectances between 0,01 and 0,90;
- Colorimetry.
Base unit
The candela, symbol cd, is the SI unit of luminous intensity in a given direction. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, igual a 683, quando expressa em lm W¯¹, unidade igual a cd sr W¯¹, ou cd sr kg¯¹ m¯² s³, sendo o kilograma, o metro e o segundo definidos em função de h, c e ΔvCs.
Derived units
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- Photometric
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- Radiometric
Luminous intensity, illuminance, regular transmittance and reflectance
A photometric bench with standard lamps and a standard photometer and, on one hand, high performance spectrophotometers with standard filters and standard ceramic tiles, calibrated by the national Metrology Institutes (NMIs) of France, the LNE, for the Photometry and of the United Kingdom, the NPL, for spectrophotometry with participations in interlaboratory international comparisons guarantee the traceability to SI.
Refractive index
In the field of Refractometry, the traceability to SI is obtained through a high performance refractometer and reference materials produced by the NMIs of Poland, the GUM, from Germany, the PTB and from the United States of America, the NIST.
Road speed
In this field, the traceability to SI is obtained through the calibration of reference speedmeters, GPS receptors, by the NMI of Switzerland, the METAS. The metrological traceability of the measurement results of the quantity time is obtained from the national standard of the second. No domínio do comprimento, esta rastreabilidade é obtida do padrão nacional do metro.
External documents:
Principles governing photometry, 2nd edition, BIPM, 2019
Jornal Oficial das Comunidades Europeias, L 272, 3 de outubro de 1990, Anexo 2.
See here available services.
International Recognition
The calibration services displaying the symbol are covered by the Calibration and Measurement Capabilities available in the CIPM Mutual Recognition Arrangement (CIPM MRA) database, the KCDB.
Olivier Pellegrino
Tel.: +351 212 948 179
E-mail: opellegrino@ipq.pt
Refractometry:
Ricardo Mendes
Tel.: +351 212 948 315
E-mail: ricardom@ipq.pt
Road Speed:
Mário Condeço
Tel.: +351 212 948 386
E-mail: mcondeco@ipq.pt
