The stability of some Zener-diode-based voltage standards

• Published in: IEEE transactions on instrumentation and measurement 1995-04, Vol.44 (2), p.226-229
• Main Authors: Witt, T.J., Reymann, D., Avrons, D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Diodes; Electronics; Exact sciences and technology; Frequency; Humidity; Laboratories; Measurement standards; Metrology; Metrology, measurements and laboratory procedures; Physics; Spectral analysis; Stability analysis; Temperature; Testing, measurement, noise and reliability; Units and standards; Voltage
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/19.377817

We report on a study, carried out from the point of view of users of Josephson array voltage standards, of factors limiting the precision of Zener-diode-based electronic voltage reference standards of the type (Fluke 732A) most widely used for Josephson voltage measurements. Frequency-dependent voltage noise was studied with a very low-frequency spectrum analyzer, and was found to be the major factor limiting short-term stability to about one part in 10/sup 8/. For two of the three reference standards tested, humidity effects were the principal factors limiting the medium- and long-term stability of the 1.018 V outputs. These effects were studied by subjecting the standards to step-function changes in relative humidity. For example, increases in ambient relative humidity of 0.01 were found to provoke decreases of 0.05-0.15 /spl mu/V in the 1.018 V output of one Zener. The time lag between the humidity change and the voltage change is characterized by a time constant /spl ges/19 days.< >