The Keithley 6485 Picoammeter is a 5½-digit instrument engineered for highly sensitive current measurements from 20 fA to 20 mA across eight selectable ranges. This feedback picoammeter delivers measurement speeds up to 1000 readings per second while maintaining exceptionally low voltage burden—less than 200 µV on lower ranges and less than 1 mV on the 20 mA range—enabling accurate measurements in circuits with very low source voltages.
Technical Specifications
• Current measurement ranges: 20 fA through 2 nA to 20 mA DC
• Resolution: 5½ digits
• Measurement speed: Up to 1000 readings per second
• Voltage burden: <200 µV (all ranges except 20 mA); 5×10¹¹ Ω in parallel with <1 nF
• NMRR (50/60 Hz): 60 dB
– Key Features
• Feedback picoammeter architecture minimizes measurement loading
• Model 485 emulation mode eases legacy system upgrades
• One-touch front panel operation
• Temperature coefficient: 0.1 × (% reading + offset) per °C outside 18–28°C
– Interfaces & Integration
• GPIB (IEEE-488) and RS-232 programmable control
• Trigger Link interface with six independent selectable trigger lines on single connector
• Scaled, inverting ±2 V analog output for direct connection to DMMs, data acquisition boards, oscilloscopes, or strip chart recorders
– Physical Specifications
• Dimensions: 90 mm H × 214 mm W × 369 mm D
• Working depth (including cord and connectors): 394 mm
• Net weight: <2 kg
Successor to the Keithley Model 485, the 6485 adds a 20 mA range and dramatically higher measurement throughput.
