The HP 4140B pA meter/dc voltage source is part of component-measurement instrumentation. It consists of an extremely stable picoampere meter and two programmable dc voltage sources, one of which operates as a ramp and staircase generator as well as a dc source. These features make the HP 4140B ideal for making dc characteristic measurements such as leakage current, current voltage characteristics, and quasi-static C-V measuremcnts, required by the semiconductor industry for new product development and for improving production yields. It is equally useful in measuring electronic components and materials to determine leakage currents or insulation resistances. The HP 4140B can contribute to the development, production, and quality control of semiconductor devices and to improvements in the reliability of electronic components and equipment.