6485

Measures low currents quickly, accurately, and economically

The 5½-digit Keithley 6485 Picoammeter combines Keithley’s expertise in sensitive current measurement instrumentation with enhanced speed and a robust design. With eight current measurement ranges and high-speed auto-ranging, this cost-effective instrument can measure currents from 20fA to 20mA, taking measurements at speeds up to 1000 readings per second.

The Keithley 6485’s 10fA resolution and superior sensitivity make it well suited for characterizing low current phenomena, while its 20mA range lets it measure currents high enough for applications such as measuring 4-20mA sensor loops.

Although it employs the latest current measurement technology, it is significantly less expensive than other instruments that perform similar functions, such as optical power meters, competitive picoammeters, or user-designed solutions. With a price that’s comparable to a general-purpose DMM, the Keithley 6485 makes picoamp-level measurements affordable for virtually any laboratory or production floor.

Low-Voltage burden and Higher accuracy

While DMMs typically employ shunt ammeter circuitry to measure current, the Keithley 6485 is a feedback picoammeter. This design reduces voltage burden by several orders of magnitude, resulting in a voltage burden of less than 200µV on the lower measurement ranges. The low voltage burden makes the Keithley 6485 function much more like an ideal ammeter than a DMM, so it can make current measurements with high accuracy, even in circuits with very low source voltages.

Successor to the Model 485

The Keithley 6485 builds on the strengths of one of Keithley’s most popular picoammeters, the Model 485, offering an additional 20mA measurement range, as well as much higher measurement speeds. With a top speed of up to 1000 readings per second, the Keithley 6485 is the fastest picoammeter Keithley has ever made. It offers ten times greater resolution than the Model 485 on every range. A time-stamped 2500-reading data buffer provides minimum, maximum, and standard deviation statistics. A built-in emulation mode simplifies upgrading existing applications originally configured with a Model 485. This emulation mode makes it possible to control the Keithley 6485 with any custom code written to control the Model 485. Refer to the comparison table for additional information.