The 6220 model DC current source and the 6221 model AC/DC current source combine ease of use with extremely low current noise. In testing environments, from research and development to production, particularly in the semiconductor, nanotechnology, and superconductor industries, low current sources are crucial for applications. The 6220 and 6221 models feature high-precision sources and built-in control functions, making them ideal for applications such as incremental mode, pulse measurement, and differential conductivity measurements using Hall measurements, resistance measurements, etc.