Guildline’s 6623A Series of High Current Range Extenders / Sources is based on patented technology and provides the best in performance and modularity. The 6623A Series consists of a family of range extenders, with available current outputs from 3 A to 10,000 A.

*Range Extender manuals available for download - 6623A Manuals


  • Unique Guildline PATENTED Design
  • Dual Design – Extender and Precision DC Source
  • Includes Built-in Precision Current Source with Electronic Polarity Switching
  • Linearity: ± 0.01 ppm of Full Scale
  • Output Current Stability Typically < 10 ppm for 1000 A and Higher - Best in the World!
  • Advanced Modular Design, Over 64 Expandable Outputs in 150 A Increments to 10,000 A, Investment Protection
  • Measures Resistances Down to 0.1 μΩ
  • Automatic Control from 6622A Series Bridge
  • Automatic Load Balancing
  • NO External Power Supplies Required
  • NO Need for any Mechanical Reversing Switches and Compressed Gas
  • Unique USB Programmable Controller (model 66259) Allows 6623A to be Used as Stand-Alone Precision DC Current Source
  • Safety (Fault) Protections in Place
  • Complete Shunt Measurement Systems Available