| Zugriffsnummer | 12795 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Cryogenic radiometer facility of the CENAM and first international comparison |
| Autor(in); Institution |
Stock, Klaus D.; 4.11, Radiometrische Einheiten, PTB-Braunschweig
Hofer, Helmuth; 4.11, Radiometrische Einheiten, PTB-Braunschweig
Su.aacute.rez Romero, José G.; Centro National de Metrología (CENAM), Querétaro, MEXICO
Gonz.aacute.lez Galv.aacute.n, Laura P.; Centro National de Metrología (CENAM), Querétaro, MEXICO
Schmid, Wolfgang; Centro National de Metrología (CENAM), Querétaro, MEXICO
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| Quelle/Jahr | Metrologia: 37 (2000), 4, 269 - 271 |
| ISSN | 0026-1394 |
| Verlag | Sèvres: BIPM |
| Freie Schlagworte | Cryogenic radiometer ; radiometric comparison |
| Zusammenfassung | A new modern cryogenic radiometer facility has recently been installed at the Centro National de Metrología (CENAM), Querétaro, Mexico. The radiometer head is a CryoRad II (CRI Inc., Boston, USA). In a specially designed laboratory with clean-room atmosphere, the facility is now ready for calibrations of detectors with power-stabilized laser radiation. This cryogenic radiometer facility will be the basis for most of the radiometric and photometric calibrations of the CENAM. A first radiometric comparison between the CENAM and the Physikalisch-Technische Bundesanstalt (PTB), Germany, was carried out with trap detectors at the He-Ne laser wavelength of 632.8 nm. Two reflection trap detectors, each with three photodiodes, were used: one with 10 mm x 10 mm and the other with 18 mm x 18 mm Si photodiodes. The results were very encouraging. At power levels of about 100 µW the calibrations showed a relative difference of 7 x 10-5 or even less. The PTB calibrations are based on a modified LaseRad II (CRI) radiometer that has been compared with cryogenic radiometers of other types and from other national metrology institutes |
