Final report on APMP key comparison of local realization of ITS-90 above the silver point using radiation thermometers as transfer standards, APMP-T-K5-97

Abstract

In key comparison APMP.T-K5, a radiation thermometer was used as a transfer standard for radiance temperature measurements at a blackbody radiation source or a standard lamp at nominal temperatures Tnom from 962 °C to 2800 °C. The transfer standard was hand-carried from the pilot laboratory, NMIJ (Japan), to a participant where it was compared with the participant's standard within the range from 962 °C to 2800 °C and was returned to the pilot laboratory. In the case of the blackbody comparison, a copper-point blackbody was carried along with the thermometer to ensure the thermometer stability. The pilot calibrated the thermometer before and after each transport. Seven institutes joined the comparison: KRISS, NIM, NMIA, NMIJ, A*STAR, KIM-LIPI and CMS/ITRI. Five institutes participated in both key comparisons CCT-K5 and APMP.T-K5, and among them four institutes acted as the linking laboratories: KRISS, NIM, NMIA and NMIJ. The linkage process is described in the Addendum of the APMP-T-K5 Final Report.The degree of equivalence of each laboratory with respect to the CCT-K5 key comparison reference value, TR, is given by a pair of terms: Di = (Ti − TR) and Ui, its expanded uncertainty (at 95% confidence level), both expressed in kelvin. This uncertainty includes the uncertainties in the original laboratory calibrations, the standard deviation of the average difference, the uncertainties of the key comparison reference values and of the link between the APMP and CCT key comparison from 962 °C to 1700 °C. From 1800 °C to 2800 °C the APMP reference value was determined from the average of the participating laboratories including the pilot.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).