Fully-Automatic DMM Calibration System
White Papers
This paper describes a fully-automatic calibration system for digital multimeters (DMMs), and uncertainty estimation of the DCV measurements of the system. A connection mechanism whose rating is more than 1000 V/1 A/1 MHz was developed for the system. By using compressed air to drive the mechanism, we were able to eliminate operator bias, as well as improve the thermal electromotive force and measurement repeatability of the system. For the standard in the system, an 8½-digital multimeter was used, which was calibrated by the standards laboratory of Keysight Technologies Japan Ltd. The measurement uncertainty was estimated by referring to the ISO Guide to the Expression of Uncertainty in Measurement (GUM).