Development of Automatic Calibration System for Solid-State DC Voltage Standards and Its Validation

A manual calibration system for the solid-state DC voltage standard has been established at the National Measurement Standard (SNSU-BSN).The manual calibration was timeconsuming, fatiguing, and difficult to collect data.To improve this measurement process, SNSU-BSN has developed an automatic calibration system for solid-state DC voltage standards using programmable software for data acquisition and a low thermal scanner for switching during the measurement.A differential measurement method is performed for automatic calibration system in 1.018 V and 10 V.This automatic calibration system has been validated with manual calibration mode for measurement repeatability in same environmental condition.The result shows that the standard uncertainties of repeatability for automatic and manual calibration at a nominal voltage of 1.018 V are 0.0035 μV and 0.0071 μV, and for a nominal voltage of 10 V are 0.090 μV and 0.038 μV, respectively.The normalized error (En number) values of nominal voltage 1.018 V and 10 V are less than 1, stating that the results of automatic and manual measurements are in good agreement.Therefore, the automatic measurement system can be applied to replace the manual process of measurement at SNSU-BSN since this method is faster and has better uncertainty values.