Comparison of MIKES and PTB precision current sources based on capacitor charging

A new traceable low current source based on charging a capacitor by a ramp generator consisting of two digital-to-analog converters has been developed by MIKES. The current source has been compared with the ramp generator current source of PTB at currents between 10 fA and 100 pA. No significant deviations were observed at uncertainty levels ranging from about 20 μA/A at 100 pA to about 7 mA/A at 10 fA.