Maintaining 10 VDC at 0.3 PPM or Better in Your Laboratory

There is a need today to maintain dc voltage at an uncertainty of 0.3 ppm or better. We believe that most standards laboratories can do this without using an expensive Josephson Junction Array System. DC Reference Standards commonly in use today are capable of this performance providing that they are properly calibrated and that the effects of temperature, pressure and seasons are taken into account. This paper develops supporting uncertainty equations and applies them to useful scenarios.