Keithley KEITHLEY 485 Autoranging Digital Picoammeter

The Keithley 485 Autoranging Picoammeter provides 100fA sensitivity with 4 1/2 -digit resolution in a low-cost, highly sensitive, easy-to-use instrument. The 485 measures DC current on seven ranges covering 10 decades from 100fA to 2mA. The input can withstand overloads as high as 1000V (with 100k-ohm limiting resistor). An analog output linearly converts the incoming current to voltage for hard copy output or control loop applications. The 485 has several features that facilitate measuring low current. In the AUTORANGE mode, the 485 maximizes resolution. The REL button makes readings relative to the baseline (the reading prior to touching the button). The LOG button converts the display to the logarithm (base 10) of the absolute value of the measured current. Digital calibration is performed from the front panel or over the bus. A 100-point DATA STORE buffer collects and stores measurements at one of six automatic reading rates from three per second to one per hour, or manually with the STORE button. Minimum and maximum readings are continuously updated at three per second in the DATA STORE mode. Display: 41/2-digit LCD, 0.5 in height; polarity, range, and status indication. Measures from 2 nA to 2 mA full scale with a 1 year accuracy of ±(0.4% + 4 counts) on the 2 nA range (worst case). Manual or autoranging. Analog output (+1 V = -10000 counts, except +100 mV on 2 nA range). DC voltage input 50V to 350V.