Keithley 486 Picoammeter

The Keithley 486 Picoammeter is a 5½-digit autoranging instrument engineered for precision measurement of low-level DC currents from 2 nA to 2 mA. It delivers 10 fA resolution with fast reading rates up to 180 readings per second and autoranging within 100 ms, making it ideal for rapid data acquisition in sensitive current measurement applications.

– Technical Specifications

Measurement Performance
• Current ranges: 2 nA to 2 mA
• Resolution: 10 fA
• Display: 5½-digit
• Reading rate: 180 readings/second
• Autoranging time: <100 ms typical; <200 ms to final range (analog filter OFF)

Accuracy (1 Year, 18–28°C, properly zeroed)
• 2 nA range: ±(0.3% of reading + 500 fA)
• 20 nA range: ±(0.2% of reading + 3 pA)
• 200 nA range: ±(0.15% of reading + 20 pA)
• 2 µA range: ±(0.15% of reading + 200 pA)
• 20 µA range: ±(0.1% of reading + 2 nA)
• 200 µA range: ±(0.1% of reading + 20 nA)
• 2 mA range: ±(0.1% of reading + 200 nA)

Input Specifications
• Maximum continuous input voltage: 505 VDC
• Voltage burden: <200 µV (inputs <100 µA); <2 mV (inputs ≥100 µA)
• Temperature coefficient (voltage burden): 20 µV/°C
• Maximum input capacitance: 10 nF (nA/2 µA ranges); 1 µF (20 µA/200 µA/mA ranges)
• Overload protection: 350 V peak (nA and 2 µA ranges); 50 V peak (20 µA, 200 µA, 2 mA ranges)

Stability & Noise
• Temperature coefficient (0–18°C, 28–50°C): ±(0.15 × applicable accuracy specification)/°C
• Time stability (24 hours, constant temperature): ±(0.003% + 1 mV)
• Wideband noise: 60 dB at 50 Hz or 60 Hz integration

Data Acquisition
• Measurement buffer: 512 readings
• Programmable reading interval: 10 ms to 999.999 s (1 ms increments)
• Programmable trigger delay: 1 ms to 999.999 s (1 ms increments)
• Selectable current limit: 2.5 mA ±0.5 mA or 25 µA ±5 µA
• Triggering: Front panel, IEEE-488 bus, rear panel BNC (one-shot or continuous)

– Key Features

• Selectable analog and digital filters optimize noise performance and wide-band response
• REL (Relative mode), ZERO CHECK, and CORRECT functions compensate for offset errors
• Display with three selectable intensity levels for varied lighting conditions
• Fastest IEEE-488 mode: 100 readings/second at 4½-digit resolution

– Typical Applications

Photodiode and photodetector measurements, ultra-low-current semiconductor characterization, leakage current testing, radiation detection, and electrostatic discharge monitoring.

– Compatibility & Integration

IEEE-488 interface enables seamless integration into automated test systems and computer-controlled measurement setups.