الفهرس | Only 14 pages are availabe for public view |
Abstract ABSTRACT The units of voltage and resistance are maintained in the national standards laboratories by the Josephson Effect and the Quantum Hall E!Tect. The Saturated Standard Cell, the Zener-diode standards and the standard resistors are used to transfer these units for direct current measurement from the national standards laboratories to othe:r users. The standard cells and zener-diode standard as well as standard resistor are preserved in the standards laboratories. With these and a variety of equipment, direct current and voltage can be measured with high accuracy. Since there is no ac counterpart to the standard cell, measurements of alternating current, voltage, and power are made relative to these same standards. The chain of measurements is extended to these alternating quantities by AC-DC Transfer instruments. They have a flat and known frequency response and hence may be calibrated on direct current and then used for alternating current measurements. |