Exceptional measurement integrity for a range of functions","Choose from three sensitive options for precision high resistance and low current measurements. The 5½-digit Model 6514 and Model 6517B Electrometers offer 1fA sensitivity, >200TΩ input impedance on voltage measurements, and charge measurements down to 10fC. The 6½-digit Model 6430 Sub-Femtoamp Remote SourceMeter SMU Instrument can measure current with 1aA sensitivity. Its low noise and drift performance make it ideal for research on single electron devices, highly resistive nanowires and nanotubes, polymers, and electrochemical applications.