In order to increase the capacity of the NIST 10V Josephson Voltage Standard System for automatic calibration of Zener reference standards from the present 32 channels, a 64 channel low thermal scanner was procured. In the NIST JVS system, the scanner output lines are cross-connected to cancel the thermal emf of scanner channels. The new scanner has, therefore, been fully characterized in this mode to simulate the same measurement condition as in "NISTVolt" software used for automatic calibration of Zener reference standards. The results of this characterization show that thermal emfs of the scanner channels are well within the required 50 nV, and hence, it was put in use with the conventional NIST 10 V Josephson Voltage Standard system. The control charts of automatic calibrations of Zener reference standards using this new 64 channel scanner and the previous 32 channel scanner show that the trend of the data taken over several months follows the same trend line, and hence, the new scanner is taken to be verified and to be working satisfactorily.
Proceedings Title: Proceedings of Measurement Science Conference
Conference Dates: January 22-26, 2007
Conference Location: Long Beach, CA
Conference Title: Measurement Science Conference
Pub Type: Conferences
Calibration, Josephson voltage standard, low thermal scanner, Zener reference standard