Vol.3 No.3 2010
Research paper : National electrical standards supporting international competition of Japanese manufacturing industries (Y. Nakamura et al.)−223−Synthesiology - English edition Vol.3 No.3 (2010) 4 Situation at the NMIs of other countriesQuestion (Katsuhisa Kudo)In “3.2 Development of the new method to respond to the demands”, you describe the method for deriving the capacitance from the quantized Hall resistance, and this is something to be proud of. Please add the percentage of the NMIs that derive the standard from cross capacitance and those that do from quantized Hall resistance, as well as any foreign NMIs that employ the method newly developed by AIST.Answer (Yasuhiro Nakamura)Among the NMIs that use cross capacitors, the ones that realize high-precision capacitance are NMIA (Australia), NIST (USA), PTB (Germany), and LNE (France), as described in the text. Other than these, NIM (China) and VNIIM (Russia) realize the standard using the cross capacitor. The ones that derive their capacitance from the quantized Hall resistance, other than AIST, include NPL (England), CMS (Taiwan), and BIPM. However in all cases, the capacitance standard is realized using the conventional quadrature bridge circuit, and the multi-frequency system of AIST is a step ahead internationally.5 New method of standard provisionQuestion (Katsuhisa Kudo)It is written in “5 Future issues” that you are “considering the development of a new dissemination method…”. While this may be a common issue for the metrological standards, do you have any ideas you can add?Answer (Yasuhiro Nakamura)Other than the “remote calibration method” described in this paper, another consideration is a system where a “long-term stable standard” is installed at the industrial sites, and this will enable calibration of the devices easily and at any time on site. For example, it may be possible to realize a “long-term highly stable standard voltage-current generation device” by combining the Josephson voltage standard and the thin-film thermal converter AC/DC standard. By developing such “technology that allows direct calibration at industrial sites” and then transferring this technology to industry, it may be possible to reduce the cost and time required for calibration. I think this will allow further rationalization of the traceability system.