| Zugriffsnummer | 22331 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Towards a more accurate and reliable source based radiometry and photometry |
| Autor(in); Institution |
Hartmann, Jürgen; 7.3, Hochtemperatur- und Vakuumphysik, PTB-Berlin
Anhalt, Klaus; 7.3, Hochtemperatur- und Vakuumphysik, PTB-Berlin
Taubert, Richard Dieter; 7.3, Hochtemperatur- und Vakuumphysik, PTB-Berlin
|
| Quelle/Jahr | Proceedings of the CIE Expert Symposium on Advances in Photometry and Colorimetry:(2008), 147 - 151 |
| Schriftenreihe | CIE X: 033 |
| ISBN | 978-3-901906-73-2 |
| Verlag | Vienna: CIE |
| Konferenzangaben | 2008 CIE Expert Symposium on Advances in Photometry and Colorimetry, Turin, 7-8, July, 2008, Italy |
| Zusammenfassung | The invention of cryogenic radiometers as primary detector standards in the late 1970s enables the measurement of optical radiation with relative uncertainties as low as 10-5. Basing on the cryogenic radiometer calibration of filter radiometers and photometers is performed at the Physikalisch-Technische Bundesanstalt (PTB) with relative uncertainties in the spectral responsivity of about 10-4. Realisation of this detector based scale is time consuming and requires a very high experimental skill level and costly equipment. The transfer of these low uncertainties to industry is often hindered by the lack of stable and accurate filer radiometers and photometers as transfer instruments in industrial environment. So far the level of uncertainty of the transfer instruments in industry is in most cases around 10-2, i.e. a factor of 100 higher than the level obtained at the PTB. An alternative attempt for transferring these low uncertainties to industry is the application of stable radiation sources as transfer standards. The radiation sources currently used in photometry, e.g. tungsten strip and FEL lamps, are not stable enough and do not supply calculable optical radiation over a wide wavelength range. Only seven years ago the invention of novel high-temperature fixed-point blackbodies based on metal-carbon and metalcarbide-carbon (M(C)-C) eutectics enables a promising solution for stable and calculable radiation sources for temperatures up to 3200 K. Table 1 gives an overview of the available M(C)-C eutectics. Meanwhile blackbodies based on M(C)-C eutectics have reached a high level of accuracy and stability (see Figure 1) and can now serve as high-quality instruments for transferring the low uncertainties of the cryogenic radiometer to industry. The talk describes the details of the M(C)-C eutectics and the transfer of the low uncertainties of cryogenic radiometers with the help of filter radiometers and photometers to science and industry with the aid of blackbody radiators based on MC eutectics. Practical examples for the application of M(C)-C eutectics in industry and calibration laboratories are given. Also available on CD-ROM. |
