A new automatic system for calibrating the solid state DC voltage reference standards at NIS,Egypt

A new automatic system for calibrating the solid state DC voltage reference standards (Zener Diode reference standards) has been established at National Institute for Standards (NIS), Egypt to disseminate the unit of volt in the country. Besides, this system has been implemented as a coherent structure that, from the national DC voltage reference standards, can disseminate the traceability of all the instruments under calibration. The system consists of a set of programmable instruments and proper software. The software of the system has been built using the Laboratory Virtual Instrument Engineering Workbench (LabVIEW) graphical language. The system hardware is configurable by the operator on the basis of the specific calibration to be performed and it allows large number and different models of Zener diodes to be act either as reference units or as units under calibration. The design and the implementation of the system software have been discussed in details. Furthermore, the system validation has been carried out for the measurement repeatability and the results compatibility in both automatic and manual modes.